# Parting tool chatter



## OrangeAlpine

What causes it?  I've made a very rigid parting tool holder that mounts directly on the compound and makes a very rigid setup.   Usually works like a dream, but sometimes get chatter.  It really seems to be a random event as it comes and goes with the same setup.  Sometimes touching up the tool helps, but not always.  The tool is spang on center and flat on top.  I've tried varying the grind angle, sometimes it helps, usually does not.  When it does  smooth the cut, the next cut may chatter.  Using a .090" wide blade.  Chatter starts the moment the tool touches the part.

Using a WWII era HSS blade.

Any suggestions?

Bill


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## stevehuckss396

I usually reduce the speed of the spindle. Sometimes getting below 100rpm on some metal and well above 500rpm on others. If I get chatter my go to solution is less rpm


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## WOB

A rigid toolholder is not a cure for a flexible compound/cross slide arrangement.  The best you can do is make sure the tool holder is centered on the compound to cross slide pivot axis, minimize tool overhang,  sharp tool, and tighten the compound gibs.    Try setting the tool a little above center so that when it flexes down in the cut it approaches center.  Starting on center allows the tool to flex down and away from the cut, reducing engagement setting up a chatter situation.  Always use power cross feed when parting to maintain constant pressure on the tool.

WOB


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## fabricator

It's all about the rigidity of the entire saddle assembly. The machine size and mass has a lot to do with it also as does the material being parted.


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## SmithDoor

Increase the rake angel on the cut off blade

Dave


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## SmithDoor

There one other trick is put around 7° on the front of cutter .
This will give a cleaner cut off. If everything is right there will tip and end of the cut.
I have trick in download section under cutters

Dave


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## goldstar31

I'm using a rear mounted parting tool blade, projecting an 1" to part off round mild steel bar 2" in diameter but am using it as a lathe tool proper as my front tool is set to cut a chamfer in a bit of 3/4" round bar- down to 1/2" round at one end and the rear tool to reduce the stock to 0.3125". Both ends are going to be tapped. The thin end- with a female 2BA thread and the thicker end M6 female . 

It's for the forerunner to the Worden grinder- called the Kennet.  Lubrication? Good old lard lard oil.
Ironically, both tools were by the same guy as wrote and designed the GHT Rear parting tool.

Basically, i'm merely following 'the book'

Norman


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## SmithDoor

I use very thin blades
It gives better cut and less chatter The down side is the blade may brake if move the carriage

Dave



goldstar31 said:


> I'm using a rear mounted parting tool blade, projecting an 1" to part off round mild steel bar 2" in diameter but am using it as a lathe tool proper as my front tool is set to cut a chamfer in a bit of 3/4" round bar- down to 1/2" round at one end and the rear tool to reduce the stock to 0.3125". Both ends are going to be tapped. The thin end- with a female 2BA thread and the thicker end M6 female .
> 
> It's for the forerunner to the Worden grinder- called the Kennet.  Lubrication? Good old lard lard oil.
> Ironically, both tools were by the same guy as wrote and designed the GHT Rear parting tool.
> 
> Basically, i'm merely following 'the book'
> 
> Norman


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## Fred Madsen

First, I am using a mini lathe and have experienced all of the above problems. My "solution " was to turn the tool upside down and run the lathe lathe in reverse. Remember that the cutting edge of the tool is now just slightly above the C/L. Try this and experiment with the height adjustment.
Please let me know if this has helped you?
P.S.   My speed depends on the material and what I am prepared to suffer in breakages, (remember I am using a mini lathe).


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## goldstar31

I have two 'mini lathes. a Myford Super 7 with a gear box and power crossfeed- which will swing ( just) 7 inches across the shears and a SiegC4 with no gear box but will swing 8 inches- and no gap like the ML7

I have only broken one thin blade and that was on a then clapped out other ML7B- now reconditioned and sold for the newer machine.

Years ago, I made a GHT Thomas rear parting tool and it is on the new-er Myford. Again, it will go on the Sieg( as will almost ALL my Myford bits from years back- and now.

The TWO most obvious answers are the probability of a worn or  or badly adjusted lathe.
The other is parting off from the front. 

For the umpteenth time, a front mounted parting tool will 'go into cut' whereas a rear mounted and  inverted and the lathe running normally  will lift "out of cut' and avoids breakage etc.

Actually, the much vaunted and coveted Myford Super7's saddle is weaker than the Sieg C4. 
As has been explained times without number, once one has bought a Myford which is not cheap, buying the appropriate books by expert owners is relatively  inexpensive.

Instead of rushing off to seek a an internet course - from whoever fancies themselves as an expert, it is better to read, learn and inwardly digest.

Something to think about- and try?

Norman


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## Steamchick

Wierd.. reversing the lathe and using the tool upside-down! The saddle is designed to be "more rigid" in normal mode... In reverse the gib-strip and taper slide loading is reversed.... but maybe this induces more friction with the changed leading and thus damps-out the chatter? 
Not something I will try, as after setting the saddle and cross slides correctly my chatter dissapeared. I do not have a power feed (luxury) but 2-handed feed is good (55 years practice?). Don't  wind with the handle, work the circular disc of the feed handle hand-over-hand to keep the feed constant and slow, and you should learn to feel good cutting. And slow the speed of the work. While I may be machining at hundreds of rpm, I probably part at 1/2 to 1/3 speed. The material being removed instead of being say 10 this wide is 100 thou wide when parting, slow as the cross sectional area of the cut is related to the work you can do, the feed-rate must be 1/10th of your normal facing speed. Also, the cutting speed reduces as the diameter of cut reduces, so you must slow down the feed, or speed up the rotation as the diameter of cut reduces. SHARP TOOLS are a must, with text book relief. Chatter suggests the tool is too flexible when everything else is good. Shorten the overhang to minimum required.
Enjoy!


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## Steamchick

I agree other comments - and I am one of those  authors of "Internet advice" but not an expert machinist. Just an engineer with a bit of machining experience. Please teach me anything where my advice is off-line.
Ta!


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## Fred Madsen

Wow   I want to know more!


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## Fred Madsen

Steamchick said:


> Wierd.. reversing the lathe and using the tool upside-down! The saddle is designed to be "more rigid" in normal mode... In reverse the gib-strip and taper slide loading is reversed.... but maybe this induces more friction with the changed leading and thus damps-out the chatter?
> Not something I will try, as after setting the saddle and cross slides correctly my chatter dissapeared. I do not have a power feed (luxury) but 2-handed feed is good (55 years practice?). Don't  wind with the handle, work the circular disc of the feed handle hand-over-hand to keep the feed constant and slow, and you should learn to feel good cutting. And slow the speed of the work. While I may be machining at hundreds of rpm, I probably part at 1/2 to 1/3 speed. The material being removed instead of being say 10 this wide is 100 thou wide when parting, slow as the cross sectional area of the cut is related to the work you can do, the feed-rate must be 1/10th of your normal facing speed. Also, the cutting speed reduces as the diameter of cut reduces, so you must slow down the feed, or speed up the rotation as the diameter of cut reduces. SHARP TOOLS are a must, with text book relief. Chatter suggests the tool is too flexible when everything else is good. Shorten the overhang to minimum required.
> Enjoy!


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## lemelman

A rear-mounted tool-post is one of the best ways of reducing parting-off chatter.


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## Peter Twissell

As stated several times above, rigidity of the whole setup is key. This is not just the toolholder, cross slide and saddle, but also the whole machine, spindle bearings, chuck and the workpiece itself.
Sometimes it is possible to reduce or eliminate chatter just by changing speed. Everything has a natural frequency and if the frequency of your setup is close to the spindle speed, chatter is more likely.
Beware of suggestions to run in reverse - if you have a screw-on chuck, it is a disaster waiting to happen.


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## tornitore45

Slow the RPM/Feet-per-Minute considerably below the regular turning and
 (I know this is controversial) keep the tool an hair lower.


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## Fred Madsen

I was going to  make a funny comment, then I thought   better of it . I only want to turn on a lathe a tailstock   040854348


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## Fred Madsen

This is not what I thought it was, I have a 67 " lasy mill but it looks as if it can do more


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## Fred Madsen

Steamchick said:


> I agree other comments - and I am one of those  authors of "Internet advice" but not an expert machinist. Just an engineer with a bit of machining experience. Please teach me anything where my advice is off-line.
> Ta!


What advice can you give me


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## Fred Madsen

lemelman said:


> A rear-mounted tool-post is one of the best ways of reducing parting-off chatter.


and is from knowledge?


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## packrat

Quote 
"Chatter starts the moment the tool touches the part."

Did you try cutting fluid when you cut off..? Sorry if this has been asked.


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## Fred Madsen

Yes the tool did tuch.


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## Richard Hed

Peter Twissell said:


> As stated several times above, rigidity of the whole setup is key. This is not just the toolholder, cross slide and saddle, but also the whole machine, spindle bearings, chuck and the workpiece itself.
> Sometimes it is possible to reduce or eliminate chatter just by changing speed. Everything has a natural frequency and if the frequency of your setup is close to the spindle speed, chatter is more likely.
> Beware of suggestions to run in reverse - if you have a screw-on chuck, it is a disaster waiting to happen.


Absolutely!  My 8tpi even with the setscrew set tightly will come loose and make a disaster.  However, I am waiting, praying and waiting for a new lathe with which I can test this rear cutoff idea out.  In the mean time, some times I can cut maybe 100 thou in but I have to make a cut about half the blade thick extra, that is, I use blades about 50 thou so naturally, I needs a cut about 75-100 thou wide which virtually eliminates side friction problems.  Also, sometimes, I have a problem (where I needs to eliminate all the probs spoken of above) in which I must be some how work hardening the material for it acts as if it has a tough skin.  Once I gets thru the "skin" it cuts well but I have to feed faster than I would like.  When I first started doing cut offs, I broke more blades than I could count (in Chinese anyway.)

Anyways, Orange Alpine, can you tell us more characteristics of the chattering?  Slow speed?, special type of metal?  cutting oils?  any thing else?


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## SmithDoor

I use very thin blades
It gives better cut. The down side is the blade may brake if move the carriage

Dave



goldstar31 said:


> I'm using a rear mounted parting tool blade, projecting an 1" to part off round mild steel bar 2" in diameter but am using it as a lathe tool proper as my front tool is set to cut a chamfer in a bit of 3/4" round bar- down to 1/2" round at one end and the rear tool to reduce the stock to 0.3125". Both ends are going to be tapped. The thin end- with a female 2BA thread and the thicker end M6 female .
> 
> It's for the forerunner to the Worden grinder- called the Kennet.  Lubrication? Good old lard lard oil.
> Ironically, both tools were by the same guy as wrote and designed the GHT Rear parting tool.
> 
> Basically, i'm merely following 'the book'
> 
> Norman


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## awake

One thing that I have both read and experienced is that sometimes chatter can be eliminated not only by slowing the rpm but also by increasing the feed. This is of course a matter of balance! Someone else mentioned using power feed for consistency, and I've read that elsewhere ... but haven't had good results doing that on my lathe. I do better with hand feeding, being able to push it more when I need to "dig under the chatter," then pull back to clear chips.

On the rigidity of an upside down parting blade - this is something that gets beat to death, with proponents for and against. On the one hand, using the parting tool right side up seems like it would be more rigid because the pressure is down onto the bed. On the other hand, there is an argument to be made that the lifting pressure of a reverse mounted setup increases the wedging action of the crossfeed dovetails, thus making it more rigid.

I would tend to say, try both and see what works *on your machine*. My suspicion is that this is not a one-size-fits-all decision.


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## tornitore45

> but also by increasing the feed.


There lay the learning process. Is a fine line between too aggressive a feed and digging in and to timid a feed and scraping which result is chattering.
Think of the tool/part as the Fiddlestick/String relationship.  A gentle rubbing plays the violin, I have no experience on what a heavy paw does to the violin.

Like everyone starting out I was chattering, digging and busting tools to no end until, by a slow learning process I learned to grind the tool right, slow down and keep that curl coming out.   It was a white knuckles, clenched teeth experience until learning the stay in the right conditions envelope.

We can write and share but is one of those thing one has to learn the feel.


As for the rear post or equivalent Upside down/reverse method the principal issue has nothing to do with altered rigidity of the set up.

Consider the tool post as being hinged down on the cross slide toward you.

By pressing on the cutting edge the tool goes Down AND Advances toward the part. This increase the downward pressure increasing the dig in until either the chip is cut or the tool breaks in the former case the cycle restarts.

With the tool upside down, an increase pressure lift the tool and pushes it away from the part until an equilibrium is reached.

In other words the two situations can be explained in term of positive feedback versus negative feedback.


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## Ozwes007

Speed should be 2/3 of your cutting speed, don’t go slow, it makes it worse! Check your chuck to ensure you have zero play in the job, you would be surprised as to how many lathes have small amounts of play in the head bearings and have bellmouth chuck jaws. Use a TDI to check, and put some decent pressure on the job to check it. I’ve probably broken 2 part off tools in 40 years of machining , center height and crappy jaws. If you cant get rid of the play then you will need to set up a rear mount parting off system, it’s the only way you can get old lathes to part off sometimes. As to feed to part off at, that should be the same as your facing speed, just slow it down near the last part. Use a catcher to keep the parting off safe, I.e. a tool up the middle for a bush, or a bush over the outside  for a solid part. Tools angles? I’ve seen nearly every angle you can imagine, but high front clearance (7 to 10) is good with a top rake to suit the material. Center height is critical, I go slightly high to allow for tool flex in older holders, lathes etc, but only half a thou. Hope this helps. At high speeds the tool loads quickly so you need to feed to maintain that load. Any play in the cross slide will kill your tool.


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## Peter Twissell

"Consider the tool post as being hinged down on the cross slide toward you.

By pressing on the cutting edge the tool goes Down AND Advances toward the part. This increase the downward pressure increasing the dig in until either the chip is cut or the tool breaks in the former case the cycle restarts."

I have a Drummond Roundbed lathe.
Discuss....


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## Timehunter

I agree with Awake and tornitore45, plus good ideas rom WOB, Fabricator, gpldstar31, Peter Twissell, and smith door except for the thin blade part.
The OP has not posted again so I wonder if he found the problem or is still having the problem.
I always use slow to really slow rpm and hand feed.
For cutting fluid I use an acid brush dipped in dark thread cutting oil and hold it on the part just above the parting blade.
Make sure it is not sticking too far out the chuck and the tool as close to the holder as possible.
I hate having to use (and seldom do), a live center in the tailstock for support as when you get close to the end things get dicey.
And can not stress the importance of what was previously posted as to keeping your machine well oiled and adjusted.
Good luck!!!


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## justintime

Fred Madsen said:


> What advice can you give me


Primary importance is properly adjusted spindle bearings including preload. Solid tool & holder with “textbook” grind ( On Center ) will help you get the best results. Good luck.


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## tornitore45

Nothing wrong with using the tailstock center, but make sure you pull it back before cutting trough.  If the cut off piece is heavy protect the ways with the protector you have built.  You did build a way protector for when changing chucks, did you?


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## tornitore45

> I have a Drummond Roundbed lathe.
> Discuss....



I am not familiar with the construction details of your lathe but the hinge I was referring to is not a real hinge is just a mental picture.   The actual hinge is distributed all along the "beam" that connects the bed to the cutting edge.  No matter the shape and construction, the beam flex under strain.


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## Peter Twissell

In the round be lathe, the 'virtual' hinge axis is directly below the spindle axis, so downward pressure on the front mounted tool tends to push it away from the job. Conversely, upward pressure on a rear mounted tool would tend to push it into the job.
The location of the virtual hinge axis will vary with the design of the machine and the relative stiffness of the components, so it is not surprising that we see a variety of individual experiences with the benefits or otherwise of rear parting tools.


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## goldstar31

tornitore45 said:


> Nothing wrong with using the tailstock center, but make sure you pull it back before cutting trough.  If the cut off piece is heavy protect the ways with the protector you have built.  You did build a way protector for when changing chucks, did you?



I would disagree.  This is one of the jobs which a fixed steady is recommended


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## Ken I

Having had the experience of production parting off 4" solid mild steel stock with a 3/8" blade on a "monster" Bardons & Oliver cut off lathe down through various size autos to my Chinese 20mm spindle hobby lathe - that can barely part off anything - let me add my 2c worth.

Firstly the laws of physics are out to get you - cutting forces reduce with increasing velocity - that creates the very propensity for all cutting operations to chatter - hence you need rigidity to avoid flexing.
If the whole shebang flexes (there will always be some) then the cutting speed reduces and the cutting force force increases - thus further reducing the speed and increasing the force until the machines' resultant forces "win" and the reverse happens - hey presto chatter.

So obviously anything that reduces the forces and increases rigidity is going to help.

Use the narrowest blade that will safely do the job with the minimum of stick out for the job.

Part off as close to the chuck as you can - my experience tells me you get less chatter on a 4 jaw and less again on a collet chuck or profiled soft jaws - but I'll be hornswoggled if I can give a rational explanation for that. I suspect three pressure points induce vibrations that just simply go from bad to worse - more support - less propensity to vibrate ?

Upside down (backslide) or reverse parting can help inasmuch that it helps to clear swarf - but you can achieve the same thing with a swarf breaker - the double beveled edge on the top of the blade can be left as is - i.e. don't sharpen the top but instead use a holder that gives the top rake by holding the blade at that angle.

I went to the trouble of making an upside down (backslide) part off holder and my Chinese lathe positively hated it - some slideway designs won't cope with it either.

If you must use the blade flat, you can grind in the rake on the corner of the wheel to hollow it out - both methods "narrow down" the resulting swarf thus allowing large clock spring swarf to accumulate without seizing. I prefer the "hollowed out" to the "double bevel" approach to "narrowing" the swarf.





Carbide part off tip - with hollow configuration to reduce the swarf width to less than the groove width. Hobby lathes are typically not powerful or rigid enough to use such tooling.
Parting off on an under powered and insufficiency rigid hobby lathe is a somewhat hit and miss affair. Typically I pull the bade out if I sense the swarf is being "chomped" down onto the blade - I then offset the blade with the compound slide ±0.2mm so that I'm working a part off groove wider than the swarf - left to right in a series of cuts with only the last cut to part off being on size (if at all - for once-off parts you are normally going to turn it around and second op. it).

A "pip-free" front clearance angle increases the cutting width and projects the swarf towards the component - neither of which are desirable - but sometimes it works well but not always - that said it is my default part-off configuration - in a production environment you want to mass produce pip free parts - but I will switch to a straight face on problem materials.

Typically cut off at half or less normal SFM and going slower or feeding harder is my go to when it starts to chatter - powerfeed if you have it.

Use lubricant - a PITB with no coolant pump and handfeeding - you need more hands.

On some materials (Stainless) an aggressive front rake works well but normally to be avoided.

Not everything works every time - let experience be your guide.

Regards - Ken


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## packrat

Quote by ken l "Use lubricant - a PITB with no coolant pump and handfeeding - you need more hands "

Yes it is a pain in the butt with hand feeding but it sure makes a nice cut with no chatter.....


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## minh-thanh

*The big problem : is with lots of helpers but the questioner has solved the problem yet ?*
I saw some people ask questions and then disappear.


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## BaronJ

minh-thanh said:


> *The big problem : is with lots of helpers but the questioner has solved the problem yet ?*
> I saw some people asking questions and then disappear.



Yes this seems to be the way of the world !  Few reply with thanks for solving my problem.


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## SmithDoor

I found most do not want to grind rake angle to the top of cut off blade.
After running turret lathes and screw machines this was only way to take out chapter. This also works on wide form cutters too.

Dave



minh-thanh said:


> *The big problem : is with lots of helpers but the questioner has solved the problem yet ?*
> I saw some people asking questions and then disappear.


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## SmithDoor

FYI
On some metals I have use 20° rake angel. I use this with both carbine and high speed steel.
Form cutter 1" wide too.

If read books be for high speed steel they take about high rake angles 

Dave


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## goldstar31

I'm now being that  bit careful as he probably have had a lathe for more than 20 years.


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## tornitore45

> In the round be lathe, the 'virtual' hinge axis is


.......
Good analysis, however round bed lathes are fairly rare except for watchmaker duty where parting is not much of a problem.


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## Steamchick

Thanks all I am just a contributor. But agree that machine stiffness is the limiting factor. Reduce all slide clearances by setting of gib-strips, etc.... Slow rpm - Agree 1/ 2 - 1/3 of normal cutting speed. I prefer a back tool post as then only 2 slides affect the Physics, not 3. But the saddle must not lift at the back at all. I have learned a lot of snippets from your various comments. Thanks!


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## firebird

Hi
I know I have joined this a little late but I can offer a few ideas that might help. I have had a lot of the problems mentioned above so decided to solve a lot of the issues I was having. I completely re designed and built a rear parting tool







I wrote an article describing the build which has just been published in the July issue of Engineering in miniature

Cheers

Rich


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## OrangeAlpine

I am the OP and am still here, reading and learning.  I still have the problem as I have changed nothing.  Life is keeping me out of the shop, I'm hoping that changes soon.   What really mystifies me is that immediately after making the new holder, parting became a dream with zero problems and nicely coiled chips.  After 20-30 cuts, the chatter suddenly appeared.   Suddenly appeared using the same setup, cutting the same bar of steel at the same speed and feed, using the same cutting oil.  There are some things that challenge the minds ability to cope.  This fits in that category.

Looks like checking the rigidity of _everything_ will be the first task, then I'll start exploring changes to the actual cutting operation.

Bill


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## Dusty3v0

minh-thanh said:


> *The big problem : is with lots of helpers but the questioner has solved the problem yet ?*
> I saw some people ask questions and then disappear.


True but give us something to talk about.


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## goldstar31

Engineer's Blue or black permeant ink the cutting edge. Then sharpen it until ALL the marker disappears.
Let ME know what happens, please. 

I was using my rear parting tool to the GHThomas design just now.  I dropped the speed a pulley and hand fed. 

Unless someone has failed to tell you, this is screwcutting as well


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## justintime

justintime said:


> Primary importance is properly adjusted spindle bearings including preload. Solid tool & holder with “textbook” grind ( On Center - “no pip” )  will help you get the best results. Good luck.


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## BaronJ

firebird said:


> Hi
> I know I have joined this a little late but I can offer a few ideas that might help. I have had a lot of the problems mentioned above so decided to solve a lot of the issues I was having. I completely re designed and built a rear parting tool
> 
> 
> 
> 
> 
> 
> I wrote an article describing the build which has just been published in the July issue of Engineering in miniature
> 
> Cheers
> 
> Rich



Hi Rich,

Certainly looks solid enough !
Just a couple of criticisms if I may.  Overhang !  The loading on the tool is outside the top slide width and will cause twist into the direction of the headstock.

Angle !  The tool angle will change as the cutting tip is set for the center line of the work.  More so if the height of the tool blade is changed.  While I can see that the holder is designed to handle only a specific height.  Many will object to the cost of the inserts and holder. 

Not having seen your article I can't say more.


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## BaronJ

OrangeAlpine said:


> I am the OP and am still here, reading and learning.  I still have the problem as I have changed nothing.  Life is keeping me out of the shop, I'm hoping that changes soon.   What really mystifies me is that immediately after making the new holder, parting became a dream with zero problems and nicely coiled chips.  After 20-30 cuts, the chatter suddenly appeared.   Suddenly appeared using the same setup, cutting the same bar of steel at the same speed and feed, using the same cutting oil.  There are some things that challenge the minds ability to cope.  This fits in that category.
> 
> Looks like checking the rigidity of _everything_ will be the first task, then I'll start exploring changes to the actual cutting operation.
> 
> Bill



Hi Bill,
Make sure that your parting blade is still sharp !


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## SmithDoor

Steamchick said:


> Thanks all I am just a contributor. But agree that machine stiffness is the limiting factor. Reduce all slide clearances by setting of gib-strips, etc.... Slow rpm - Agree 1/ 2 - 1/3 of normal cutting speed. I prefer a back tool post as then only 2 slides affect the Physics, not 3. But the saddle must not lift at the back at all. I have learned a lot of snippets from your various comments. Thanks!


When running screw machines I cut off 3/4" hex 12L14 steel at 1,500 RPM. All cutters was HS steel.

Just look at the rake angel on drill bit.
Have you had chatter on drill bit???

Dave


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## BaronJ

Hi Guys,

I know that I've posted pictures of my Norman patent rear tool post and parting blade holder before.  But since its relevant to this thread...





Since this picture was taken I've modified the holder and rounded the back edge to match the front one.










The mounting position is such that the body of the post is inside the width of the top slide and the blade can be set against the face of the chuck in order to ensure that it is dead square to the work.

That blade is 2 mm thick by 12 mm wide and is 200 mm long.  It cost less than £2 from Banggood.  In this picture the blade has not been sharpened yet.


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## SmithDoor

It looks great

A lot what have I read on this thread is what try back 1960's when first started.

Here list what try back 1960's
1) feed down 0.000,5" 
2) use back gears 
3) very fast feed in backs do not do this the blade breaks into thousand pisces.
4) lot of oil
5) wide blades
6) thin blades
7) carbide.

One many tries the blade broke with rake and it cut great.

The books I just did not cover the cut off tool angle.

I can remember my pain and see everyone pain here.

Grinding the rake so hard to do the first few times. 
But upside is the blades lasted longer since they not breaking off.

Dave




BaronJ said:


> Hi Guys,
> 
> I know that I've posted pictures of my Norman patent rear tool post and parting blade holder before.  But since its relevant to this thread...
> 
> View attachment 117248
> 
> Since this picture was taken I've modified the holder and rounded the back edge to match the front one.
> 
> View attachment 117249
> 
> 
> View attachment 117250
> 
> The mounting position is such that the body of the post is inside the width of the top slide and the blade can be set against the face of the chuck in order to ensure that it is dead square to the work.
> 
> That blade is 2 mm thick by 12 mm wide and is 200 mm long.  It cost less than £2 from Banggood.  In this picture the blade has not been sharpened yet.


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## tornitore45

> 12L14 steel


One can cut 12L14 with a butter knife and no lubrication.
One has to try hard to get chatter with free cutting steel.


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## SmithDoor

I can remember the setting for that stock.
I have run DOM tub and A36  steel just good but do not remember the settings I used.

Dave



tornitore45 said:


> One can cut 12L14 with a butter knife and no lubrication.
> One has to try hard to get chatter with free cutting steel.


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## goldstar31

I was re-reading 'Thomas' again and noted that  in addition to making a parting tool capable of cutting  2" diameter but GHT also had a small parting  tool using a piec e of 3/16th round HSS.  After grinding the tool was positioned pointing up 6 Degree( avoiding unnecessary loss of blade but each blade in his collection was do wn to 15 thous or  0,015". Then each of his ser=t of homemade tools was 'waisted'

I think that he  had a professional tool and cutter grinder but from photos, he also had his own prototype  'Kennet' tool and grinder which was the prototype to the 'Worden one.
My Kennet was damaged and bits lost when howling gales removed- for the second time

It is keeping me occupied as I am not only locked down  but 'shielded' in the pandemic- and my new shed

Something to think about, perhaps?

Norman


----------



## OrangeAlpine

Managed to find some time for the shop and I'm back.  Tightened up everything, especially around the headstock.  

Initially, I saw almost .002" of spindle movement at the front edge of the chuck.  After tightening the inner bearing (tapered roller) it is now almost .001".  Spindle rotation is stiffer.  Stange thing, I tightened the bearing to the point I could not rotate the spindle by hand and still had almost .001" of movement.  Don't know where the slop is, but its going to stay.

Discovered and rectified a problem with the chuck mount.  I had gotten a little sloppy when mounting the chuck and it might have been the main problem.   Checked the crossfeed gibs, tightened ever so little.  Cross compound was already plenty tight.  Besides, I lock it down unless its in use.

Performed one cutoff operation, went beautifully at about 75 rpm and power feed.  This is better steel than I was using when the problem appeared.  No changes at all to the cutting tool or holder.

So all the talking about machine rigidity paid off for me.  

Thank you, one and all.

Bill


----------



## Tim Wescott

I must be freaking lucky, because I don't have much problem with my Smithy 1220 -- which probably isn't any better than any other cheap lathe.

Something not mentioned here, but which I heard somewhere, is to keep the feed rate up.  If you're tentative, at least on my lathe, it _will_ chatter.  I take a deep breath, act like I'm jumping into ice-cold water and *feed it in*.  Sometimes it'll start to chatter and I can make it stop by feeding it harder.

I suspect this works the same as reducing the spindle speed, because either way you're increasing the amount the tool is cutting.

I use a cutoff tool with a 1/16" top.  I have it ground nice and sharp, then I take a Dremil cutoff wheel and grind a dish into it, so the part that touches the work is a bit "U" shaped (maybe only 5-10 mil deep -- it's just barely perceptible).  This seems to help make the cut smoother, by keeping the chip a bit narrower than the walls of the groove.

Disclaimer: I'm not an expert.  I'm an electronics circuit/embedded software/high-tech systems designer by day, the last time I earned money doing metalwork I was 18, and I was bending thin-wall square tubing and making crappy welds, in the pursuit of reinforcing fiberglass molds.


----------



## jack620

Tim Wescott said:


> Something not mentioned here, but which I heard somewhere, is to keep the feed rate up.  If you're tentative, at least on my lathe, it _will_ chatter.  I take a deep breath, act like I'm jumping into ice-cold water and *feed it in*.  Sometimes it'll start to chatter and I can make it stop by feeding it harder.



Absolutely.

And sharpen your parting blade regularly. I have a USA made high cobalt HSS blade in an Aloris style holder that presents the blade at 7 degrees (I think) from horizontal. So the back-rake is built in. All I have to do is give the front face of the blade a light touch on the grinder and it good to go. It's amazing how a light sharpen can turn a parting-off horror show into an easy job.


----------



## lathe nut

Tim, I have a 1220XL, they are good machines, they have a heavier cross slide and compound that a lot of the lathes of this day and time, I got mine from a fellow that had a three jaw, four jaw chuck and a load of tooling he wanted to sell it fast and I made a good deal, just needed another lathe they are all so happy in the shop together.


----------



## lathe nut

Tim, just found the picture it was at a yard sale, I probably have 200 taps and dies but those in the picture are left hand ones, how cool.


----------



## RM-MN

jack620 said:


> Absolutely.
> 
> And sharpen your parting blade regularly. I have a USA made high cobalt HSS blade in an Aloris style holder that presents the blade at 7 degrees (I think) from horizontal. So the back-rake is built in. All I have to do is give the front face of the blade a light touch on the grinder and it good to go. It's amazing how a light sharpen can turn a parting-off horror show into an easy job.



I have a mini-lathe with (as explained by someone else) the rigidity of a wet noodle but I can part off quite well with the sharp blade but I use a diamond honing stick as it needs to be sharper than what my grinder can do.  Honing all my cutters is essential with this lathe.


----------



## OrangeAlpine

Well I'm up and running with no chatter, but another evil has jumped out.  The tool wants to dig in.  I'm very slowly feeding by hand, while the tool is cutting cleanly it will suddenly dig in, taking a heavy cut.  The tool is still on center.  I'm thinking that adjusting the tool to be under center would help.   But I'd rather eliminate the cause.

Bill


----------



## jack620

OrangeAlpine said:


> I'm very slowly feeding by hand, while the tool is cutting cleanly it will suddenly dig in, taking a heavy cut.



what material are you parting Bill?


----------



## OrangeAlpine

Mystery metal steel.   It machines nicely but is not leaded.

Bill


----------



## awake

It may be a symptom of some lack of rigidity, but I have learned that on my well-worn lathe, when parting some materials, I have to feed in, then give it a moment to "digest' the bite - it continues to cut, and may pull out quite a bit, even though I'm not feeding. Then, before chatter starts, it is time to feed some more.

And some materials just seem to be problematic no matter what - at which point, I take the part out of the lathe and transfer it to the bandsaw!


----------



## OrangeAlpine

_"I take the part out of the lathe and transfer it to the bandsaw!"_

  Been there, hate to do that!
Bill


----------



## awake

I hear that! But when it becomes clear that sooner or later something is going to break, long before the material in question is going to be parted successfully ...


----------



## SmithDoor

Just look at the hook on band saw blade. This is what is need on cut off blade. 

Just watch videos of screw machines. Look closely at the blade. 
If can find old book Brown and Sharp screw machines it will a disk type cut off with lots of rake. 
Back band saw blade look.

Dave



OrangeAlpine said:


> _"I take the part out of the lathe and transfer it to the bandsaw!"_
> 
> Been there, hate to do that!
> Bill


----------



## BaronJ

OrangeAlpine said:


> Well I'm up and running with no chatter, but another evil has jumped out.  The tool wants to dig in.  I'm very slowly feeding by hand, while the tool is cutting cleanly it will suddenly dig in, taking a heavy cut.  The tool is still on center.  I'm thinking that adjusting the tool to be under center would help.   But I'd rather eliminate the cause.
> 
> Bill



Hi Bill,

Sudden dig ins can be caused by play in the cross slide lead screw,  but a much less obvious cause particularly parting aluminum is build up on the cutting edge.  Which is also why its a must to use some lubrication that will stop material sticking to the cutting edge.

WD40 is good for alloys, though I use paraffin or diesel oil.


----------



## SmithDoor

BaronJ said:


> Hi Bill,
> 
> Sudden dig ins can be caused by play in the cross slide lead screw,  but a much less obvious cause particularly parting aluminum is build up on the cutting edge.  Which is also why its a must to use some lubrication that will stop material sticking to the cutting edge.
> 
> WD40 is good for alloys, though I use paraffin or diesel oil.


All screws have play or you can not move the screw.
After the screw wears in middle now try moving the screw to ends.

Now without roller bearing the could use a cutoff tools without chatter. 

The time that seen no backlash screws in on mills.
But this was per loaded type screws using hydraulic cylinder and was only used for climb milling.

Dave


----------



## SmithDoor

This most interesting part of cut off tools is most do not want to grind a hook in top of the blade. But will stop using the blade ungrounded.

Dave


----------



## goldstar31

SmithDoor said:


> This most interesting part of cut off tools is most not want to grind a hook in top of the blade. But will stop using the blade ungrounded.
> 
> Dave



This is all discussed in 12 pages( yes 12) in G/H.Thomas's ' book 'Model Engineer's Workshop Manual.
He inclined the Parting off tool at 7 degrees which, inverted does not require a hook. Of course grinding a hook on a parting tool makes a mess of the quite expensive tool and takes a long time to regrind on top and bottom. 
Actually, I've just reground a parting tool with this hooked configuration. It came from a box of someone else's rejects.
The maths between the two is roughly, 0.0088 x the diameter of the grinding wheel in inches x the degrees required with the andwer in nthe  height or depth of from the centre of the grinding spindle.
Professor Dennis Chaddock simply produced the chart in his Quorn book- assuming the his readers were none too bright.

Anyway, I fitted a Quorn spindle into spindle holder on a Kennet tool and cutter grinder( the forerunner of the Worden which I am starting to make. I noted that Thomas suggested a soft while Aloxite wheel wheras the one that I got was a 60 grit one.  Having said all that, I created almost a mirror surface for cutting.
Err, uhm, I'm making an arbor to go on my Mark 1 Quorn to diamond swop for the final honing.

Hope this clarifies things somewhat.


----------



## SmithDoor

My Aloris #7  UNIVERSAL PARTING BLADE HOLDER has 4° angle. Which I think would have the correct angle for cutoff blade. It works on very few metals at that angle.
There no way to adjust the angle. So back to grinding.
At less I had background in screw machines to know the angle.

I do believe this gives a false angle to everyone.

I have even design a holder for 15° that fit the Aloris tool post.

Dave



goldstar31 said:


> This is all discussed in 12 pages( yes 12) in G/H.Thomas's ' book 'Model Engineer's Workshop Manual.
> He inclined the Parting off tool at 7 degrees which, inverted does not require a hook. Of course grinding a hook on a parting tool makes a mess of the quite expensive tool and takes a long time to regrind on top and bottom.
> Actually, I've just reground a parting tool with this hooked configuration. It came from a box of someone else's rejects.
> The maths between the two is roughly, 0.0088 x the diameter of the grinding wheel in inches x the degrees required with the andwer in nthe  height or depth of from the centre of the grinding spindle.
> Professor Dennis Chaddock simply produced the chart in his Quorn book- assuming the his readers were none too bright.
> 
> Anyway, I fitted a Quorn spindle into spindle holder on a Kennet tool and cutter grinder( the forerunner of the Worden which I am starting to make. I noted that Thomas suggested a soft while Aloxite wheel wheras the one that I got was a 60 grit one.  Having said all that, I created almost a mirror surface for cutting.
> Err, uhm, I'm making an arbor to go on my Mark 1 Quorn to diamond swop for the final honing.
> 
> Hope this clarifies things somewhat.


----------



## goldstar31

SmithDoor said:


> My Aloris #7  UNIVERSAL PARTING BLADE HOLDER has 4° angle. Which I think would have the correct angle for cutoff blade. It works on very few metals at that angle.
> There no way to adjust the angle. So back to grinding.
> At less I had background in screw machines to know the angle.
> 
> I do believe this gives a false angle to everyone.
> 
> I have even design a holder for 15° that fit the Aloris tool post.
> 
> Dave



I'm not into QCTP and as you mention an Aloris( whatever that is when it's at home) but my maths suggests  that 4 degrees is an angle suitable for carbide tools. 
No Dave,  I DID research into cutting acoustic tiles made from spun rockwool- but that was in the 50's.
I'd just got out of 'battledress' and wanted a few coins.  Surprisingly,  most of the Masonic Halls still have suspended ceilings with them.   

I hope that I will not be 'blackballed'

So mote it be

Norman


----------



## SmithDoor

I try carbide too.
Looks great on paper
 I try on  A36 and DOM tubing
I found A36 and DOM like about 15° to 20° angle, it will cut like butter.

I did not like wasting cutoff blades but had to do the work.
Let put this I started use band saw then to Turret lathe. Lot band saw blades.

Dave



goldstar31 said:


> I'm not into QCTP and as you mention an Aloris( whatever that is when it's at home) but my maths suggests  that 4 degrees is an angle suitable for carbide tools.
> No Dave,  I DID research into cutting acoustic tiles made from spun rockwool- but that was in the 50's.
> I'd just got out of 'battledress' and wanted a few coins.  Surprisingly,  most of the Masonic Halls still have suspended ceilings with them.
> 
> I hope that I will not be 'blackballed'
> 
> So mote it be
> 
> Norman


----------



## jack620

SmithDoor said:


> My Aloris #7  UNIVERSAL PARTING BLADE HOLDER has 4° angle. Which I think would have the correct angle for cutoff blade. It works on very few metals at that angle.



You must be doing something wrong. I have the same toolholder with a very good quality 2mm parting blade fitted. Since adding the new blade I have no trouble parting any metal now. That includes titanium.

This blade: T-Type Cut-Off Blades H.S.S. | Somma Tool Company
The 5/64” cobalt version.

Keep it sharp, keep the lube up, keep the feed up.

I agree with Norman. You shouldn’t need to grind a hook in a parting blade.


----------



## SmithDoor

I purchased a book from Brown and Sharp screw machine from the 1920's.
It gave the table for cutoff tools and metals.
After read the book had more problems using a cutoff tool.
The two worst metals that I work with was A36 a DOM tubing 

PS .
First it was 9N making the parts later it was Turret lathe. Very long days. 
Finally made parts on A25 screw machine just stand back and watch.






jack620 said:


> You must be doing something wrong. I have the same toolholder with a very good quality 2mm parting blade fitted. Since adding the new blade I have no trouble parting any metal now. That includes titanium.
> 
> Keep it sharp, keep the lube up, keep the feed up.
> 
> I agree with Goldstar. You shouldn’t need to grind a hook in a parting blade.


----------



## jack620

SmithDoor said:


> The two worst metals that I work with was A36 a DOM tubing



OK. A36 is listed as structural steel, so I would expect it to be ugly to part-off. And DOM tubing has a welded seem. I haven't tried parting it, but I imagine the weld would provide an interruption to the cut, being harder than the rest of the tube. I can see that introducing chatter.


----------



## SmithDoor

Here photos I found 
Show the higher angle

Dave


----------



## SmithDoor

jack620 said:


> OK. A36 is listed as structural steel, so I would expect it to be ugly to part-off. And DOM tubing has a welded seem. I haven't tried parting it, but I imagine the weld would provide an interruption to the cut, being harder than the rest of the tube. I can see that introducing chatter.


They both fun cut .
I have Manufacturer door and crane wheels 26" diameter x 6" wide using A36, plunge cut for double flanges.

Dave

PS: I still have a  full package of carbide inserts for plunge cutters that did not work.
I first cut the outside face with carbide. Then plunge with hand sharpen HHS tool bit.


----------



## SmithDoor

Website for books on old machine tools




__





						Brown & Sharpe Mfg. Co. - Publication Reprints | VintageMachinery.org
					





					vintagemachinery.org
				




Dave


----------



## justisla

I have just been through this thread & cannot see anyone mentioning making 2 cuts.
I have had a very elasticated Warco 240 MV from new. (My Drummond M seemed more rigid.) One can watch the cutter dipping visually millimetres, not thous. I cannot run a low revs because the variable speed motor will constantly stop. That happens even for simple turning operations. That can make parting off an "interesting" activity to say the least.

If the metal removed can help cause a cutter to jam- & I believe it can- then making a second cut to increase space for the chips to clear makes sense, does it not?
I have found that I do better if I cut to a depth where I feel things getting tight when hand feeding (that is really a mixture of, nerves, feel, revs dropping & tool dipping) I withdraw the cutter, move over a cutter width, go in again but deeper. I can usually do this fairly fast & confidently, because the chips are clearing quickly. Then go back to the first cut again cutting deeper. Alternating, until finished, or giving up & resorting to the hacksaw.
Seems to work for me- most of the time that is


----------



## Steamchick

Stiffness in the lathe is everything under heavy tool loads like parting-off. I have had various small lathes, fro  a 1960s right-hand thread lathe with 3 in swing (my Grandfather's), and Unimat from 1960s to my current Chinese 6 in swing. None of these small tools work like big stiff lathes for parti -off. On a single piece of steel I have had 3 cuts consecutively where the part "worked Ok", next dug -in and next was best and fastest feed rate. The "worked Ok" cut was at a slower feed speed (by hand), because the workpiece was projecting more from the chuck,  the  next final was Ok when I figured a feed-rate that worked, and the last was close to the chuck.
I feel that the last time I sharpened my tungsten a carbide tool I must have got the grinding "just right" as it is set on a back tool post. My notion is that as the cuts were on different projections from the chuck that affected the total stiffness of the lathe and the bad cut was at a point where something was resonating at that stiffness. THe other cuts at different system stiffnesses didn't  hit the resonance and therefore cut Ok.
Certainly, there is always a sweet-spot for feed rate , part rotational speed, etc. And the lathe bed stiffness is the thing you can't  change. On smaller lathes I have seen the bed twist under dig-in loads, and this will happen on any lathe if you can get a high enough load. All the advice about tool rake, sharpness, finish, feed rate being higher, etc. is valuable as all these factors contribute to dig-in and chatter. But there are limits on every lathe and set-up where too high a feed will dig-in, and if you have any significant play you will get chatter. I suspect the initiator for resonance is the torque variation (quite a high frequency) from the poles of the motor, or belt drive resonance, or something relating to a ripple on the rotational speed. This excites resonant frequency or harmonic based on the stiffness of the whole lathe. Once initiated the resonance causes a ripple on to pressure which in turn causes momentary dig and release.... This then accelerates into chatter. CHANGE SOMETHING to change the stiffness and the chatter seems to magically dissapear. But what to change can be any of these various factors that make it work. It is a bit of a black at for the less experienced (I.E. me!).
Thanks for you advice - it has helped me.
Discuss. 
Ken


----------



## SmithDoor

Steamchick said:


> Stiffness in the lathe is everything under heavy tool loads like parting-off. I have had various small lathes, fro  a 1960s right-hand thread lathe with 3 in swing (my Grandfather's), and Unimat from 1960s to my current Chinese 6 in swing. None of these small tools work like big stiff lathes for parti -off. On a single piece of steel I have had 3 cuts consecutively where the part "worked Ok", next dug -in and next was best and fastest feed rate. The "worked Ok" cut was at a slower feed speed (by hand), because the workpiece was projecting more from the chuck,  the  next final was Ok when I figured a feed-rate that worked, and the last was close to the chuck.
> I feel that the last time I sharpened my tungsten a carbide tool I must have got the grinding "just right" as it is set on a back tool post. My notion is that as the cuts were on different projections from the chuck that affected the total stiffness of the lathe and the bad cut was at a point where something was resonating at that stiffness. THe other cuts at different system stiffnesses didn't  hit the resonance and therefore cut Ok.
> Certainly, there is always a sweet-spot for feed rate , part rotational speed, etc. And the lathe bed stiffness is the thing you can't  change. On smaller lathes I have seen the bed twist under dig-in loads, and this will happen on any lathe if you can get a high enough load. All the advice about tool rake, sharpness, finish, feed rate being higher, etc. is valuable as all these factors contribute to dig-in and chatter. But there are limits on every lathe and set-up where too high a feed will dig-in, and if you have any significant play you will get chatter. I suspect the initiator for resonance is the torque variation (quite a high frequency) from the poles of the motor, or belt drive resonance, or something relating to a ripple on the rotational speed. This excites resonant frequency or harmonic based on the stiffness of the whole lathe. Once initiated the resonance causes a ripple on to pressure which in turn causes momentary dig and release.... This then accelerates into chatter. CHANGE SOMETHING to change the stiffness and the chatter seems to magically dissapear. But what to change can be any of these various factors that make it work. It is a bit of a black at for the less experienced (I.E. me!).
> Thanks for you advice - it has helped me.
> Discuss.
> Ken


Something just trying different ways.
Mind was broken blade and later reading that was right way.

Biggest thing is to have fun.
I forget that and taken a long time to get back to having fun.
It fun just trying

Good luck
Dave


----------



## goldstar31

Steamchick said:


> .
> I feel that the last time I sharpened my tungsten a carbide tool I must have got the grinding "just right" as it
> 
> Ken



I'm left guessing about your technique.  Vaguely, I am left wondering  what thickness is your carbide parting tool and secondly, what or how you are regrinding a carbide parting tool. I think that I shall not be alone in this.

Moi? I'm really a HSS guy but I DO have ability to /access to CBN and diamond stuff too.

Here, in the wilds of sometimes sunny Gosforth and in severe lockdown and shielding, I'm trying too keep a degree of sanity starting on Worden tool grinnder- theoretically to do hss stuff.

Regards


Norman


----------



## SmithDoor

I have use both
Carbide is great for speed and life but it break faster.
Most time I use HSS low cost and does not break as often as carbide.
I can get better finish use HSS tool bits and I grind to shape faster than carbide

When do use carbide I braze carbide to steel for rake and shape I want but for long runs.

Dave



goldstar31 said:


> I'm left guessing about your technique.  Vaguely, I am left wondering  what thickness is your carbide parting tool and secondly, what or how you are regrinding a carbide parting tool. I think that I shall not be alone in this.
> 
> Moi? I'm really a HSS guy but I DO have ability to /access to CBN and diamond stuff too.
> 
> Here, in the wilds of sometimes sunny Gosforth and in severe lockdown and shielding, I'm trying too keep a degree of sanity starting on Worden tool grinnder- theoretically to do hss stuff.
> 
> Regards
> 
> 
> Norman


----------



## tornitore45

Talking about carbide for parting...

I saved a 10" carbide tipped saw blade for wood.
I am not inclined to resharpen some 40 teeth but I cut out several 1/2" strips each one with one tooth radially down to the center.

Once sharpened with a diamond stick, they make excellent parting or growing blades.

One plus is that the teeth of wood saws have alternate beveled (set) teeth with a straight raker in between. So you can have a choice of a tool that leaves the "pip" on the chucked part or on the falling off part.


----------



## dkwflight

Hi
You also might do a hone with a diamond stone on the cut off tool.  It helped me in one instance.
You also might be able to make a jack to support the toolon your carriage.
Good Luck
Dennis


----------



## SmithDoor

It just finding how too use the cutoff equipment.

Now how about the little tip left after cutoff. 

When first just joy of cut is great but do that thousand times with tip leftover 

Dave


----------



## Ken I

Mauro, thanks for reminding me to get MAIG and complete an idea from years back - to make a part off tool from a circular saw blade vis :-




I mostly use the 3/32" HSS blade and holder (top right) and was hoping this 2mm wide blade would be better.

For my first attempt, I was deliberately belligerent with the blade (stress test) without coolant - probably overheated and the tip came off.

Test #2 was done with care and coolant - it works but all in all is more trouble than my 2.4mm (3/32") blade.

So I'm going to call it a failure although the occasional job might still pop up where it might be useful.

Next I'm going to make a holder to take the standard 3/32" beveled blade and mount it at 5-7° so I don't have to grind the rake in the top and use the bevel as a chip narrowing device.

Regards, Ken


----------



## Bentwings

RM-MN said:


> I have a mini-lathe with (as explained by someone else) the rigidity of a wet noodle but I can part off quite well with the sharp blade but I use a diamond honing stick as it needs to be sharper than what my grinder can do.  Honing all my cutters is essential with this lathe.


When I worked in the shop we had a number of brand new tool room lathes were  snugged up the ways it seemed like daily finally the solution was to simply place a large chunk of steel plate on the carriages. I suppose you could say the machines wore out more but loss of production made this a moot point.   I rented time at a horrid shop on his old mill. It chattered something terrible so I tightened the gibs as much as practical and set about 100 lbs chunk of steel on the table. Chatter gone. There was a mild confrontation but he was a business man too so we compromised budgets I said I’d clean the mess his helper made when I was done . Saved him half hour wage and it took me a few more minutes to finish the job that I made a couple hour engineering pay. ( very high rate for skilled toolmaker-with eng degree.  Ya just gotta know how to bargain.LOL


----------



## tornitore45

Ken I     due to the aggressive rake of a wood saw it is best used on aluminum.   Aluminum can be cut with wood tool at wood speed.  Lacking a metal band saw I use my 10" table saw for aluminum all the times.

I used the recycled carbide wood saw to cut cooling fins in cast Iron because HSS can be a problem with cast Iron


----------



## Bentwings

Ken I said:


> Mauro, thanks for reminding me to get MAIG and complete an idea from years back - to make a part off tool from a circular saw blade vis :-
> View attachment 117440
> 
> I mostly use the 3/32" HSS blade and holder (top right) and was hoping this 2mm wide blade would be better.
> 
> For my first attempt, I was deliberately belligerent with the blade (stress test) without coolant - probably overheated and the tip came off.
> 
> Test #2 was done with care and coolant - it works but all in all is more trouble than my 2.4mm (3/32") blade.
> 
> So I'm going to call it a failure although the occasional job might still pop up where it might be useful.
> 
> Next I'm going to make a holder to take the standard 3/32" beveled blade and mount it at 5-7° so I don't have to grind the rake in the top and use the bevel as a chip narrowing device.
> 
> Regards, Ken


I just saw the picture of the saw blade. In view of the riots here we were discussing over lunch defensive weapons.  Even  at my age being ex relief baseball pitcher I’d guess I could throw that thing through a 1/4” piece of plywood at 20 feet. Hate to be on the receiving side of that tool. Bedside gun is nice but very difficult to leave in very accessible position. I don’t sleep with leather gloves on but I could present that thing effectively.


----------



## Bentwings

Bentwings said:


> I just saw the picture of the saw blade. In view of the riots here we were discussing over lunch defensive weapons.  Even  at my age being ex relief baseball pitcher I’d guess I could throw that thing through a 1/4” piece of plywood at 20 feet. Hate to be on the receiving side of that tool. Bedside gun is nice but very difficult to leave in very accessible position. I don’t sleep with leather gloves on but I could present that thing effectively.


Sorry off topic but not off mind these days.


----------



## tornitore45

I like my tool lower than center, so the pip is difficult to avoid. The only choice is on which part you get it.  By adding a little front angle one can steer the pip on one side or the other but is hardly worth the trouble.
I like my 0.040" blade and adding a front angle makes it flex and does nor cut straight.


----------



## SmithDoor

Do not worry
This is a good group.
Soon or later it will happen.

Dave



Bentwings said:


> Sorry off topic but not off mind these days.


----------



## jack620

If you're still getting chatter after trying all the tips given here, I recommend making a solid toolpost mount to replace the topslide/compound.


----------



## SmithDoor

Here my cut off blade as the last time it was used.
Note the hook at the end.
Cuts A36 like butter and no chatter

Dave


----------



## holmes_ca

I notice no member has mentioned the old spring parting holder design, I built one scaled down for my Taig lathe and you can't have a lathe much smaller than that it holds a 3/8 x 0.040 blade, it has improved my success immensely, sometimes new is not always better,

Edmund.........Alberta


----------



## jack620

Interesting Albert. My Hercus lathe (basically a metric South Bend clone) came with an Armstrong spring holder. I never liked it so I gave it away. I wonder if the improvement you saw is due to the spring design or the thinner blade?


----------



## goldstar31

jack620 said:


> Interesting Albert. My Hercus lathe (basically a metric South Bend clone) came with an Armstrong spring holder. I never liked it so I gave it away. I wonder if the improvement you saw is due to the spring design or the thinner blade?



I scrapped pr lost mine. So long go, I've almost forgotten. My GHT mentioned here gives no complaints


----------



## SmithDoor

The spring type holder die. If they where great everyone would spring type.

You find it how you sharpen the blade make cut. Just look at any saw blade it has a high rake angle. 
Just type all the wonder cutters on aluminum cast 10 minutes old. They all failed with big glob of aluminum on end of carbide cutter. But band saw would it this new aluminum casting in seconds.

Dave



jack620 said:


> Interesting Albert. My Hercus lathe (basically a metric South Bend clone) came with an Armstrong spring holder. I never liked it so I gave it away. I wonder if the improvement you saw is due to the spring design or the thinner blade?


----------



## SmithDoor

Fred Madsen said:


> What advice can you give me


Beside myself I may be the only journeyman Machinist in this group Retired.

Dave


----------



## awake

justisla said:


> I have just been through this thread & cannot see anyone mentioning making 2 cuts.
> I have had a very elasticated Warco 240 MV from new. (My Drummond M seemed more rigid.) One can watch the cutter dipping visually millimetres, not thous. I cannot run a low revs because the variable speed motor will constantly stop. That happens even for simple turning operations. That can make parting off an "interesting" activity to say the least.
> 
> If the metal removed can help cause a cutter to jam- & I believe it can- then making a second cut to increase space for the chips to clear makes sense, does it not?
> I have found that I do better if I cut to a depth where I feel things getting tight when hand feeding (that is really a mixture of, nerves, feel, revs dropping & tool dipping) I withdraw the cutter, move over a cutter width, go in again but deeper. I can usually do this fairly fast & confidently, because the chips are clearing quickly. Then go back to the first cut again cutting deeper. Alternating, until finished, or giving up & resorting to the hacksaw.
> Seems to work for me- most of the time that is



Yes, I often use this technique when parting deep depths.


----------



## tornitore45

Edmund, we discussed the virtual hinge point being below the center. The tool holder you show move the hinge point above center changing the situation from positive feedback to negative.


----------



## tech610

Try to push the crosslide in while advancing it into the cut and maintain the pressure while you are parting. You will not find this info readily available online, but because of backlash in the crosslide the tool moves in and out, digs in and out.  Keeping the pressure on will not let cutting tool move back and forth.


----------



## SmithDoor

You know they use cutoff tools for over 150 years with lots of slop
On most screw machines it is rake to feed the cutoff blade.

Dave


tech610 said:


> Try to push the crosslide in while advancing it into the cut and maintain the pressure while you are parting. You will not find this info readily available online, but because of backlash in the crosslide the tool moves in and out, digs in and out.  Keeping the pressure on will not let cutting tool move back and forth.


----------



## holmes_ca

jack620 said:


> Interesting Albert. My Hercus lathe (basically a metric South Bend clone) came with an Armstrong spring holder. I never liked it so I gave it away. I wonder if the improvement you saw is due to the spring design or the thinner blade?





Jack, I'm pretty sure it is the spring tool holder,


SmithDoor said:


> The spring type holder die. If they where great everyone would spring type.
> 
> You find it how you sharpen the blade make cut. Just look at any saw blade it has a high rake angle.
> Just type all the wonder cutters on aluminum cast 10 minutes old. They all failed with big glob of aluminum on end of carbide cutter. But band saw would it this new aluminum casting in seconds.
> 
> Dave


Jack610 you are right on, that is exactly what it does, keep the pressure on and the tool moves away relieving the cut

Edmund........Alberta


----------



## holmes_ca

Smithdoor, wrong, Journeyman tooland die


----------



## SmithDoor

holmes_ca said:


> Smithdoor, wrong, Journeyman tooland die


I only found the profile on Journeyman. It did not say the type of Journeyman and he is in the UK.

Dave
FYI: I am a Journeyman Repair Machinist


----------



## holmes_ca

I give up,


----------



## johwen

Hi johwen from under.
Being a hobby machinest for quite along time and like everybody had trouble parting mild steel I came across the T section blade see here...Works fantastic use the blade upside down and the lathe in reverse you can even use power feed... Details here
*"T" Type Parting Off Blades*




*The premium quality blades we stock are sourced from the largest manufacturer of repetition lathe tooling in the USA.


The blades have a slight hollow grind along the top (bottom) cutting edge which assists in curling the chip for easier ejection from the cut. 


The industry standard height for 1/2" "T" type parting blades is actually close to 12mm.
Please be aware that some of the cheaper "T" type blades from China and India are 12.7mm (1/2") high and will not fit the FoR inverted parting tool holder.*​
Here is the website for the manufacture of the blade holder and blades


			"T" Type Parting Off Blades
		

Hope this helps an happy parting
John


----------



## OrangeAlpine

Ah yes, the old tyme springy parting tool holder.  The device of nightmares.  I learned much of what I know about machining "back in the day", using such devices mounted in lantern tool holders on clapped out WWII equipment.

No, thank you.

Bill


----------



## jack620

johwen said:


> Here is the website for the manufacture of the blade holder and blades



John,
Eccentric Engineering don't make those blades. They are made by Somma Tools in the USA. See post #78. 
And yes, they are fantastic blades.


----------



## Noel Gordon

SmithDoor said:


> Beside myself I may be the only journeyman Machinist in this group Retired.
> 
> Dave


Dave I have been a toolmaker for more than 60 years


----------



## johwen

jack620 said:


> John,
> Eccentric Engineering don't make those blades. They are made by Somma Tools in the USA. See post #78.
> And yes, they are fantastic blades.


They make the blade holders only the blade come from the US and are well worth the extra cost and better than a wrecked job which can often happen with a chattering blade or too thick a blade. John


----------



## SmithDoor

Glad to  here 
I would think there would a lot not of us.
What type tool making did you do???

Dave



Noel Gordon said:


> Dave I have been a toolmaker for more than 60 years


----------



## scottyp

Parting off always been a bit of an adventure on my mini lathe, sometimes easy, sometimes not so easy.  I tend to run slower and lower (just a bit below center) with a T style tool, and maybe some lubrication.  I like the idea of running in reverse, I think it would compensate for some slop in the cross slide and I may give it a shot, but I am going to first going to grind some rake into my cutters.

The more of this thread that I read, the more convinced I am that the shape (and sharpness) of the cutting edge is the most important ingredient.


----------



## rsmith111333

Noel Gordon said:


> Dave I have been a toolmaker for more than 60 years


No I am a qualified Fitter, turner, machinest


----------



## TonyM

SmithDoor said:


> Beside myself I may be the only journeyman Machinist in this group Retired.
> 
> Dave


Technical apprentice. Indentured in 1965. Long time out of trade rising through the ranks. Now long time retired. I guess there are more than you imagine.


----------



## SmithDoor

I am glad I wrong 
What type of work did you do???

I started making parts for electronics projects in 1960's later model planes.
I read how some are doing machining and remember doing that way.
Some many think take backlash out the screw. You remember using some old lathes and mill where backlash was full turn of handle be for movement.

Dave



TonyM said:


> Technical apprentice. Indentured in 1965. Long time out of trade rising through the ranks. Now long time retired. I guess there are more than you imagine.


----------



## Steamchick

Geometry: Running forwards, the thrust is down on the slides and front of the saddle, and tending to lift the rear of the saddle. But the lathe makers have designed the slides and saddle to work this way. When you reverse the lathe (with reversed tools) you reverse all the thrusts on the thrust faces so "hang-on" to tapers instead of trusting onto large flat faces. Fundamentally, that is wrong. My design and engineering career tells me "NO"! But I do not have "60 years of toolmaking experience. I would expect (and also respect!) Toolmakers to have well adjusted slides, gib-strips, etc, all well lubricated and not worn, mucky, loose, etc. Not that most modellers are like that, but when I watch utube machining videos I realise that by comparison, I am. I just haven't got 40 hours per week for 60 years at it, more like a couple of hours a month for a dozen years of the 60 since my father and grandfather taught me lathe work..... so I am learning as well as chipping-in with my thoughts. 
But please don't  ignore Engineering advice. We are highly trained to solve the problems in our heads before cutting metal. Good luck trying it backwards!


----------



## Richard Hed

Steamchick said:


> Geometry: Running forwards, the thrust is down on the slides and front of the saddle, and tending to lift the rear of the saddle. But the lathe makers have designed the slides and saddle to work this way. When you reverse the lathe (with reversed tools) you reverse all the thrusts on the thrust faces so "hang-on" to tapers instead of trusting onto large flat faces. Fundamentally, that is wrong. My design and engineering career tells me "NO"! But I do not have "60 years of toolmaking experience. I would expect (and also respect!) Toolmakers to have well adjusted slides, gib-strips, etc, all well lubricated and not worn, mucky, loose, etc. Not that most modellers are like that, but when I watch utube machining videos I realise that by comparison, I am. I just haven't got 40 hours per week for 60 years at it, more like a couple of hours a month for a dozen years of the 60 since my father and grandfather taught me lathe work..... so I am learning as well as chipping-in with my thoughts.
> But please don't  ignore Engineering advice. We are highly trained to solve the problems in our heads before cutting metal. Good luck trying it backwards!


That's one of the probs with engineers without practical experience--yes, absolutely competent to do engineering work, however, often, the object being made needs something the engineer is not familiar with.  Same in the military, but possibly worse:  a military school graduate goes to war and expects the soldier to salute crisply and stiffly, but the soldier has been in the field too many days without RnR, the lieutenant may send his soldiers to do something that the sergeant would NEVER do.  So a sergeant who is sent to officers school is the better choice for a lieutenant because he has experience in the field.  I understand that engineers in Germany have to have a lot of experience in their field -- German engineers are considered, in general, to be better engineers that others.


----------



## SmithDoor

You find most do not read data or I do read it is internet {if it on internet it must be true or just like old days if on tv it must be true.}

I have shelf of engineering books some dating back 1940's and machinist books dating back to 1920's. This group that I use. If look it is may be right.
Even my brother use the books for his engineering job with L???????? Labs.

Dave
PS: Some of data in old books was not printed in later books.



Steamchick said:


> Geometry: Running forwards, the thrust is down on the slides and front of the saddle, and tending to lift the rear of the saddle. But the lathe makers have designed the slides and saddle to work this way. When you reverse the lathe (with reversed tools) you reverse all the thrusts on the thrust faces so "hang-on" to tapers instead of trusting onto large flat faces. Fundamentally, that is wrong. My design and engineering career tells me "NO"! But I do not have "60 years of toolmaking experience. I would expect (and also respect!) Toolmakers to have well adjusted slides, gib-strips, etc, all well lubricated and not worn, mucky, loose, etc. Not that most modellers are like that, but when I watch utube machining videos I realise that by comparison, I am. I just haven't got 40 hours per week for 60 years at it, more like a couple of hours a month for a dozen years of the 60 since my father and grandfather taught me lathe work..... so I am learning as well as chipping-in with my thoughts.
> But please don't  ignore Engineering advice. We are highly trained to solve the problems in our heads before cutting metal. Good luck trying it backwards!


----------



## TonyM

SmithDoor said:


> I am glad I wrong
> What type of work did you do???
> 
> I started making parts for electronics projects in 1960's later model planes.
> I read how some are doing machining and remember doing that way.
> Some many think take backlash out the screw. You remember using some old lathes and mill where backlash was full turn of handle be for movement.
> 
> Dave


My potted history. 
As a ''Technical apprentice'' in Killingworth we spent a year each in turning, milling, fitting, toolroom or drawing office, college was in three month blocks. I went on to refurbing multi spindle automatics mainly Acme Gridley and Wickman for a company in Ashington. Then moved to the southwest as a maintenance and development fitter for Hattersleys.  In the 70's I moved to Avon Rubber as a development engineer later moving onto project and facilities manager. Took early retirement in 2003 and started working for the missus. Got my lathe Warco 240 about three years ago after restoring the basement to give me workshop space.


----------



## Steamchick

I appreciate and respect the experience of toolmakers, experienced machinists et al, which is why I read this discussion. But maybe I wasn't clear in my view. To drive a machine contrary to the way the designer intends may work satisfactorily in some cases, particularly those of larger stiffer machines, especially when well maintained and set-up for minimal play, back-lash, etc. 
However, many, but not all, model "engineers" do not have such machines, but have second-hand, worn, or used but not maintained tools which are often much smaller and therefore not as stiff as is suitable for the cuts being discussed. Therefore I do not advocate the "blanket statements" of "driving the cut hard" or "running backwards". First set-up the machine to the best you can, then run it the way the designer and manufacturer intends, with the tools set as sharp as you are able, and positioned as accurately as you can. Care in set-up is everything a toolmaker does to ensure he has the best possible conditions before cutting. Please teach me correctly if I am wrong, and don't knock Engineers. It is likely that the Engineers wrote the text books revered here, or taught many of the apprentices the theory and background foundation of their trade. I do not doubt or challenge the expertise of the experienced who write here, just caution that some of their statements are subject to their particular application or condition. Please teach me if I am wrong. I read to learn, but don't appreciate your "sour grapes". Incidentally, while I have met, worked with and have learned a lot from German, Japanese, American, British, Scandinavian, Canadian, etc. Engineers, I cannot criticise, nor classify, any nationality for having "better" or "worse" Engineers. Some differences, but all work to the same principles. Think, check, think again, check, check, check, and only then "commit to the cut".
If you can't do the Engineering "thinking", then please follow the rules. I.E. run the machine the way the manufacturer intended.


----------



## Richard Hed

Steamchick said:


> I appreciate and respect the experience of toolmakers, experienced machinists et al, which is why I read this discussion. But maybe I wasn't clear in my view. To drive a machine contrary to the way the designer intends may work satisfactorily in some cases, particularly those of larger stiffer machines, especially when well maintained and set-up for minimal play, back-lash, etc.
> However, many, but not all, model "engineers" do not have such machines, but have second-hand, worn, or used but not maintained tools which are often much smaller and therefore not as stiff as is suitable for the cuts being discussed. Therefore I do not advocate the "blanket statements" of "driving the cut hard" or "running backwards". First set-up the machine to the best you can, then run it the way the designer and manufacturer intends, with the tools set as sharp as you are able, and positioned as accurately as you can. Care in set-up is everything a toolmaker does to ensure he has the best possible conditions before cutting. Please teach me correctly if I am wrong, and don't knock Engineers. It is likely that the Engineers wrote the text books revered here, or taught many of the apprentices the theory and background foundation of their trade. I do not doubt or challenge the expertise of the experienced who write here, just caution that some of their statements are subject to their particular application or condition. Please teach me if I am wrong. I read to learn, but don't appreciate your "sour grapes". Incidentally, while I have met, worked with and have learned a lot from German, Japanese, American, British, Scandinavian, Canadian, etc. Engineers, I cannot criticise, nor classify, any nationality for having "better" or "worse" Engineers. Some differences, but all work to the same principles. Think, check, think again, check, check, check, and only then "commit to the cut".
> If you can't do the Engineering "thinking", then please follow the rules. I.E. run the machine the way the manufacturer intended.


Sorry Steam, If I sounded critical, I didn't mean to be.  It is just a statement about any set of peeps who go into any professional line of work without knowing the practicalities involved.  It is true too.  The "beginning" professional thimks he/she knows it all when he doesn't.  When he/she comes in contact with a person lower on the professional ladder, they can be a real pain in the "you know what".  As far as the Germans, they really DO have a general reputation as being better than most other groups.  As for Americans, I'd be surprised if half of them could screw on a nut to bolt.  (I'm an American so I can knock them.)

The thing about lathes is that they are MADE to do many things more than what is obvious--that is all I know about the subject.  And people who own them often modify them to do even MORE things.


----------



## Steamchick

Hi Richard, I'm sorry too, if I over-reacted. But, after 50 years  of hearing  ordinary people decrying British or other nationalities of Engineers in place of - in your comment - Germans, or often (from this side of the Atlaintic) Americans, I attempt to level the field with my opinion. Competence is nothing to do with the Nationality of the Engineer, but rather his/her intelligence, aptitude experience, etc. 
I am an amateur machinist, although I started when I was about 7, making screws for clocks on my Grandfather's lathe - graving, not machine cutting the size and shape of screw, before threading with a die. I graduated to my Father's treadle lathe a year or so later, when big enough to pedal the treadle, before getting on the stool to machine a small cut. Then my sister learned to pedal while I machined.... A couple of thou cut at a time. I later had that lathe (my 3rd) after he died, and it was then powered by a quarter-horse electric motor, then I learned the limitations of over-powered small tools. With a heavy cut on back-gearing I could see the lathe twisting! But with a careful low steady continuous hand feed and good tooling, I could still part-off 1 inch dia steel, cast-iron, brass, stainless steel, wood, etc. on the 1920s lathe. (Old enough that it had RH Whitworth threads on the slides, not the "modern" square LH threads. Vis-a-vis the modern rule, "To the right makes it tight, the left slackens off". Has anyone else experienced RH threaded lathe feeds?).  But I think the key is "steady speed" = continuous cutting. 
My significant point is that a heavier cut than the stiffness of the lathe can manage will generate chatter, under-cutting, broken tools and worse, damaged parts or even a bent lathe-bed. That's my "Engineer's opinion" for what it is worth, though I do appreciate everyone's advice about their experiences and advice for this "difficult" operation for the amateur.
Perhaps one final comment for my fellow amateur machinists: Practice the 2-handed continuous feed technique using the rim of the wheel of the feed screw, not the handle. As I learned this at an early age it is easily forgotten as a part of the technique that all the older "experts" use naturally. With practice.... you can feel when the cutting speed is risking a dig-in, or needs the shaft speed increasing, or the edge going-off  on the tool. Something that an auto-feed cannot do?
Any more comments from the toolmakers? - I love to learn!
And I'm  sorry, but I do go on a bit....


----------



## Steamchick

tornitore45 said:


> Ken I     due to the aggressive rake of a wood saw it is best used on aluminum.   Aluminum can be cut with wood tool at wood speed.  Lacking a metal band saw I use my 10" table saw for aluminum all the times.


I use broken bits of inserts brazed onto whatever steel is to hand, ground with hours of patience GENTLY on a normal carborundum grind stone. But I was taught "the hare and tortoise" technique. Fast is for factories where time is a premium. Otherwise a slower, easier pace will get results and satisfaction. And remember, he factories "doing the fastest possible" have lots of expert Engineers studying how to optimise everything to get maximum performance from machines, for as long as possible, without failures. The failures are found and eliminated during the trial phases. Mailing "one-offs" in your workshop means no engineering trials, just do it right first time, every time. So a little patience goes a long way.
Incidentally, I was site engineer on an aluminium smelter build installing aluminium bus bars (120,000A. At 80V. For the interested readers). The welded joints in 30 inch by 6 inch bars was made with packs of welded 1/2 plates. All cut to fit the joint gaps with hand-held circular saws (for wood) with carbide tipped blades. Lots of blades repaired every day, replacement armatures and gearboxes for the saws every week. The saw doctor was very busy!. 
Machined flat faces for the bolted aluminium joints were made in the workshop on a wood machine using a face fly- Cutter - can't remember, maybe 6 in dia? - at 20,000rpm! Slow Hand-feed and a large cut and the swarf flew!
Bolted joint faces were 24 inches square-ish, or there abouts.
Memories.....


----------



## tornitore45

> Practice the 2-handed continuous feed technique using the rim of the wheel of the feed screw, not the handle.



Such a technique is so naturally instinctive it does not even need to be thought.
Same when turning a taper with the compound.


----------



## Richard Hed

Steamchick said:


> Hi Richard, I'm sorry too, if I over-reacted. But, after 50 years  of hearing  ordinary people decrying British or other nationalities of Engineers in place of - in your comment - Germans, or often (from this side of the Atlaintic) Americans, I attempt to level the field with my opinion. Competence is nothing to do with the Nationality of the Engineer, but rather his/her intelligence, aptitude experience, etc.
> I am an amateur machinist, although I started when I was about 7, making screws for clocks on my Grandfather's lathe - graving, not machine cutting the size and shape of screw, before threading with a die. I graduated to my Father's treadle lathe a year or so later, when big enough to pedal the treadle, before getting on the stool to machine a small cut. Then my sister learned to pedal while I machined.... A couple of thou cut at a time. I later had that lathe (my 3rd) after he died, and it was then powered by a quarter-horse electric motor, then I learned the limitations of over-powered small tools. With a heavy cut on back-gearing I could see the lathe twisting! But with a careful low steady continuous hand feed and good tooling, I could still part-off 1 inch dia steel, cast-iron, brass, stainless steel, wood, etc. on the 1920s lathe. (Old enough that it had RH Whitworth threads on the slides, not the "modern" square LH threads. Vis-a-vis the modern rule, "To the right makes it tight, the left slackens off". Has anyone else experienced RH threaded lathe feeds?).  But I think the key is "steady speed" = continuous cutting.
> My significant point is that a heavier cut than the stiffness of the lathe can manage will generate chatter, under-cutting, broken tools and worse, damaged parts or even a bent lathe-bed. That's my "Engineer's opinion" for what it is worth, though I do appreciate everyone's advice about their experiences and advice for this "difficult" operation for the amateur.
> Perhaps one final comment for my fellow amateur machinists: Practice the 2-handed continuous feed technique using the rim of the wheel of the feed screw, not the handle. As I learned this at an early age it is easily forgotten as a part of the technique that all the older "experts" use naturally. With practice.... you can feel when the cutting speed is risking a dig-in, or needs the shaft speed increasing, or the edge going-off  on the tool. Something that an auto-feed cannot do?
> Any more comments from the toolmakers? - I love to learn!
> And I'm  sorry, but I do go on a bit....


+Believe it or don't--that is one of the reasons I like to read the forum, simply to see peeps stories.  Do you still have the treadle lathe?  I had two jewelers lathes but one has gone missing.  I would like to see a photo of that lathe.


----------



## goldstar31

Richard
                 If you want 'hist ory' then might I suggest a Holzapffel OT lathe from the days, I guess of Maudsley.
They cost a street of houses and many of the crowned heads of Europe had one.  Of course they were treadle powered and had the family crest moulded into the legs of the treadle part. Records seem to show that the Tsar of Russia had one.  Until somebody bumped him off
As a youngster I learned to use a treadle sewing machine. It was a Jones but we were terribly poor then.

As for an OT lathe, Newcastle upon Tyne is claimed to have one. Along with Turbinia, I should add.
One of the curators of the Discovery Museum is in one of my lodges,  I kept trying to tie him down to have a look but he was always too busy.

I vaguely recall that Tom D Walshaw writing as Tubal Cain produced 'Ornamental Turning' should you be interested. 4 out of 5 of the Charles Holzapffel books are on the 'net. I've the 4 and they are most intersting.

Norman


----------



## goldstar31

Steamchick said:


> I use broken bits of inserts brazed onto whatever steel is to hand, ground with hours of patience GENTLY on a normal carborundum grind stone.
> Memories.....



Of course, few seem to have brazing facilities and seemingly either the lack of any form of tool grinding. r the knowledge of 'how to do it', hence the purchase of indexables- and the lack of knowledge of what to buy. It's. a vicious circle because there is a continual need for some of us to be asked to 'repeat ourselves'-- and of course-- for free.

Apologies but I have been in lockdown - since the Chinese New Year, have been shielded( whatever that is) and having to go to hospital for an injection for what passes as my reasonably good eye.
Where bloody Cramlington is - yet another mystery.
---------------------------------------------------------------------------------------------------------

In that boring  wait, I looked at the videos of an English firm, called Enots Engineering.

Earlier I had followed his construction of a tool and cutter.
This time, he grinds a parting tool for his Boxford/ South Bend lathe.

Someone MAY be interested


----------



## Steamchick

Thanks I'll have a look for Enot's videos. Hope you are well with your quarantine. And good luck with your eye. I have a friend on his last 15% of vision in his good eye, and life adjustments are very difficult for him. Puts life in perspective...
Keep on keeping on.


----------



## sniffipn

Enots talks about parting tools
---------------------------------------------------------------------------------------------------------


----------



## Steamchick

Oh, Cramlington is just north of Newcastle. A couple of miles beyond Gosforth Park.... I live in Sunderland... which translates from Norsk-Viking as "the land between good lands..."  (Probably marshy, back then). Not a native of the North-East, I had to learn how to live "in foreign parts" when I came here nearly 40 years ago. It is actually very nice, but stay away from the cold coast in Summer! - Fog on the Tyne today.... 14 deg.C. and raining.


----------



## goldstar31

Steamchick 

Thanks for the good wishes. Actually, I'm a Geordie born - just on the border which was Durham and Northumberland- now Tyne and Wear( Ugh!) and now live on what is probably bits of the Roman Wall.


----------



## Steamchick

I understand that if you are  from South of the Tyne there are reasons for your statement re: Cramlington! I manage with the Sunderland accent, But north of the river it gets a bit too broad for me, a Southerner!


----------



## goldstar31

An accent is not good for business.

One - you will note the correct expression- learns to 'scrape one's tongue'.


----------



## Richard Hed

sniffipn said:


> Enots talks about parting tools
> ---------------------------------------------------------------------------------------------------------


Yes, I've watched Enot for a long time.  And a bundle of others too.


----------



## Tim Wescott

Just for reference, here's a picture of my super-duper cutoff tool holder.  I'd never want to use this in production because you basically have to hand-assemble it each time.  But thanks to the combination of super-high-tech materials, it does hold things rigidly enough that I can part off 1 1/4" diameter steel (as demonstrated by the last shot, if you can just believe that I did it).

The tool itself is purchased; it's nicely "cutoff tool" shaped.  The aluminum block in there is tapered just right so that when I press the tool in from the side it's at the correct angle -- the super high tech top & bottom holders then transfer the force of the screws to the tool, and hold it in the correct position.

The feed has to be right -- too little and it chatters, too much and it stalls the lathe.

(And per all the "who has experience" subject -- I design electronics and write software for pay; my formal education in machining ended with a freshman combined wood, metal, and electronics shop class back when I was 13 years old).


----------



## jack620

Heath Robinson, eat your heart out.


----------



## goldstar31

jack620 said:


> Heath Robinson, eat your heart out.



Ah yes-- but does his humour travel, please? A bit like Gerard Hoffnung.


----------



## Tim Wescott

goldstar31 said:


> Ah yes-- but does his humour travel, please? A bit like Gerard Hoffnung.



"Heath Robinson" is "Rube Goldberg" in British.

And yes -- it is very much thrown together.  But the thing just insists on working, and working, and working.  So it lives on, doing all sorts of parting-off jobs quite nicely, thank you.


----------



## goldstar31

Tim Wescott said:


> "Heath Robinson" is "Rube Goldberg" in British.



'Who follows in his train?' Apologies for being a heretic.


----------



## Steamchick

Maybe because I was taught machining in the 1960s.. at a machine shop turning cast-iron cross-heads 10 1/2" diameter and weighing over 150lbs/ casting... all the tool set-up and clamping was just like this. I remember that the deformation in the micrometer (due to its own weight and stiffness - or lack thereof...) meant I had to check the OD with Mic vertically (2 ways), horizontally from above, then from below, and take a mean value... to get the parts "right" to within a thou or so. It was where I learned the different sounds of cutting... good, bad and various materials. Does anyone else remember all the different smells from different metals? - Aluminium, cast-iron, forged steel, etc. all sound and smell different and that is part of the "memory" joy for me, when machining. 
On parting, my "commercial tool holder and tool" seems to work best at a tiny bit below centre, but I do find that excess pressure makes the tool regress into the holder. Also, the tapered top edge needs to be dressed "flat" to avoid the blade wandering under cutting forces on the top face. See picture for how I set it square (the hacksaw blade is a convenient size and the teeth give me a good view of full contact on the chuck face - see how the reflections of the teeth points meet the actual teeth? - It is easier to detect out-of-alignment than a with a simple straight-edge to my eyes!) and the height of the tool. (A true vertical blade in line with the square would be exactly centre). Sorry about focus, or shake, as my camera didn't like being so close to the job. (This is about as good as I can see anyway, without a good magnifier!). The back-tool-post isn't very stiff, but is better at larger diameters than the 4-post tool holder. However, I can only cut about 3/8" deep with this tool before I have to change to the smaller commercial tool on the front tool post.
Hope you find something useful in this? (e.g. the hacksaw trick against the chuck?)

Also some carbide tips I have ground with ordinary carborundum, as I didn't know you must use diamond wheels.... some are home-made with old lathe tools and broken bits of carbide tips. Takes a bit of time and patience, but it can be done. (Time is free for me).

And on another matter, not all suppliers of tools send good ones.... sometimes you get the ones from the scrap-bin!


----------



## goldstar31

Well, I'm  or was a bean counter- I left that World for longer than I worked, I never listened.  Actually, there was a canteen full of electrical engineers who laid out moore high voltage cable there than they ever laid for 1.6 million who benefited  from the time when they were - not theorising 
But the pension- like my other ones is acceptable-- ho, ho, ho! Poor things, I spend hours sweetly mourning their  last vist into an electric oven---

And so to my 'Moonbeams from a Lesser Lunacy'.  Without a formal clue about parting off, why use the top slide to hold a FRONT parting tool?  A top slide is merely what some character out of his tiny mind, thought that he knew a man who knew a man.
Answers please?

Norman

N.B.  as a sort of addendumD I've saved money in the Covid-19 and sold my last car and saved a horrendous car insurance.
So I've added more bits in kit form to my grinder projrct and-- wait for it- both another rear parting tool kit- because I really don't feel that it is sensible to unbolt  and swop tooling between my indoor and out door little workshops

More anon if the Grim Reaper keeps away!

Norma


----------



## mcostello

In The Home Shop Machinist magazine years ago there was an article from a Guy Who regularly parted off 11" and 18" bronze. A picture showed a piece of 11" being cut. He had a thin piece of metal wedged under the cut off tool. Not to burst anyone's bubble, including Mine.


----------



## tornitore45

> He had a thin piece of metal wedged under the cut off tool.


I have a parting blade holder that provides 5 degrees rake but also use a classic parting tool in a standard QT holder. To avoid grinding a top rake angle I place a suitable thick spacer under the tool front, presto structural rake without grinding.


----------



## goldstar31

mcostello said:


> In The Home Shop Machinist magazine years ago there was an article from a Guy Who regularly parted off 11" and 18" bronze. A picture showed a piece of 11" being cut. He had a thin piece of metal wedged under the cut off tool. Not to burst anyone's bubble, including Mine.



The lathe was probably a bit larger and more rigid than a model engineer's one.
My two lahes swing 7" and 8" - respectably. 

But, but I spoke the guy who makes a kit for the LARGER version of the Thomas design- when I ordered my bits for what is laughingly called MODEL engineering .


----------



## kinggt4

Had a bit of trouble finding the Enots parting tool videos, so here is the one that compares tools:


And here is the one on grinding a parting tool:


In another video, I notice that he is using the insert tool type which I use.  I have no trouble parting off with carbide inserts.

George


----------



## SmithDoor

If you at video the carbide has a lot of rake around 10 to 15°.
This is secret of good cutoff with HSS or carbide.
The down side to carbide it is wider cut and cost.

Dave



kinggt4 said:


> Had a bit of trouble finding the Enots parting tool videos, so here is the one that compares tools:
> 
> 
> And here is the one on grinding a parting tool:
> 
> 
> In another video, I notice that he is using the insert tool type which I use.  I have no trouble parting off with carbide inserts.
> 
> George


----------



## holmes_ca

If I had a bigger motor I feel sure the operation in this video would work perfectly and on a small lathe like the Taig this op is over the top for such a small lathe, so the old fashioned spring holder is not at fault, in fact, it does the job well,


----------



## jack620

I think your lathe would have had a much easier job parting that steel if you used the lowest ratio on your pulleys.


----------



## holmes_ca

jack620 said:


> I think your lathe would have had a much easier job parting that steel if you used the lowest ratio on your pulleys.



Jack, thank you for the comment, trouble was the lathe was stalling and the motor was still turning and screaming on the smallest pulley so I went to the next bigger pulley for more grip, catch 22, I realize its not the best setup with the holder hanging out in a little block clamped to a 0.500 post with very little support but this operation is just a one-time thing my normal course would be the cutoff saw, I just wanted to show how an old ancient tool holder can still do the job,


----------



## Steamchick

Hi. I would still advise caution from my "Engineer's" head.... A bigger motor, or even  down- gearing, is seemingly a good idea because you ultimately want more torque applied. This is to overcome the shearing force exerted by the tool on the metal at the appropriate speed and feed of cut. 2 solutions, as the lathe (bed and slides) can only manage a limited torque. (If you don't  know, the cutting torque  is related to how much metal you remove = width and depth of cut, diameter at point of cut, and shear-strength of material being cut, so your lathe may be OK with a 0.0005in cut at 1in diameter, but not OK at 2 in diameter, or 0.001in cut because those both need twice the torque applied. Similarly a 2 mm tool takesc2/3rd the torque of a 3mm tool at the same diameter, feed-rate and workpiece material. )
So: 
1: reduce the feed-rate, or increase speed of rotation so each revolution cuts less metal (reduced cut = reduced torque to within the capability of the lathe stiffness).
Or 2 : Reduce the width of cut - which is how a "Modified hacksaw" blade can work, when parting tools won't. Make a tool blade using a piece from a broken hacksaw blade - e.g. of un-used teeth just on the working side of the mounting hole. Select a tooth with a zero set as the cutting point. Make a precise holder so the blade is vertical. As the blade progresses into the cut the "kerf" from the set of the following blades will make the cut wider, but lubricate the cutting point as at the first tooth there is no side clearance - hence a lot of heat generated from the cutting shear, and side friction combined. I used this on a very small lathe, that had a big enough motor/gearing, but innadequate bed stiffness for cutting with my "regular" tool, on decent steel, at a larger diameter. But the feed was GENTLY, GENTLY! Not "stuff it in hard".
Sorry to be so long winded, but it is a complex problem, and £10,000 of lathe will have a much better (easier) capability than a £500 "hobby" lathe. I have a variable-speed cheap Chinese lathe and it is great! For what it cost. But at low speed it has hardly any torque, so like the spring loaded tool holder, it naturally stops the cut if I am too forceful for the stiffness of the whole machine. Not a problem as I have the time to work carefully within its limitations, and my local club has bigger industrial machines when needed.
Enjoy!


----------



## enginemanpk

Hello 
        I usually take a cut down then back out, offset tool by 0.5mm go back in. Back out again then offset 0.5mm the opposite side then go back it. Repeat in till you cut through.


----------



## goldstar31

It will be interesting to know just how many people are actually making a Worden grinder.
Apart from me---


----------



## Richard Hed

Steamchick said:


> Hi. I would still advise caution from my "Engineer's" head.... A bigger motor, or even  down- gearing, is seemingly a good idea because you ultimately want more torque applied. This is to overcome the shearing force exerted by the tool on the metal at the appropriate speed and feed of cut. 2 solutions, as the lathe (bed and slides) can only manage a limited torque. (If you don't  know, the cutting torque  is related to how much metal you remove = width and depth of cut, diameter at point of cut, and shear-strength of material being cut, so your lathe may be OK with a 0.0005in cut at 1in diameter, but not OK at 2 in diameter, or 0.001in cut because those both need twice the torque applied. Similarly a 2 mm tool takesc2/3rd the torque of a 3mm tool at the same diameter, feed-rate and workpiece material. )
> So:
> 1: reduce the feed-rate, or increase speed of rotation so each revolution cuts less metal (reduced cut = reduced torque to within the capability of the lathe stiffness).
> Or 2 : Reduce the width of cut - which is how a "Modified hacksaw" blade can work, when parting tools won't. Make a tool blade using a piece from a broken hacksaw blade - e.g. of un-used teeth just on the working side of the mounting hole. Select a tooth with a zero set as the cutting point. Make a precise holder so the blade is vertical. As the blade progresses into the cut the "kerf" from the set of the following blades will make the cut wider, but lubricate the cutting point as at the first tooth there is no side clearance - hence a lot of heat generated from the cutting shear, and side friction combined. I used this on a very small lathe, that had a big enough motor/gearing, but innadequate bed stiffness for cutting with my "regular" tool, on decent steel, at a larger diameter. But the feed was GENTLY, GENTLY! Not "stuff it in hard".
> Sorry to be so long winded, but it is a complex problem, and £10,000 of lathe will have a much better (easier) capability than a £500 "hobby" lathe. I have a variable-speed cheap Chinese lathe and it is great! For what it cost. But at low speed it has hardly any torque, so like the spring loaded tool holder, it naturally stops the cut if I am too forceful for the stiffness of the whole machine. Not a problem as I have the time to work carefully within its limitations, and my local club has bigger industrial machines when needed.
> Enjoy!


Just one question on that:  If you are going at a slower speed (revolutions/m), then are u slowing the engine or is it a geared (or belt drive) that is changed?  I'm wondering because it seems to moi, that a geared or belt driven system would have very high torque because it is still got the same horse power behind it, just going slower.  so each rev. may be take longer but the power, proportionally, should be much higher.  but if it is driven by Variable speed machine, then all bets are off.


----------



## Richard Hed

goldstar31 said:


> It will be interesting to know just how many people are actually making a Worden grinder.
> Apart from me---


I am not familiar with the Worden.  Does u have a photo?  Are the plans in public domain?  I needs a specialized grinder and would like to build one.


----------



## goldstar31

Richard Hed said:


> I am not familiar with the Worden.  Does u have a photo?  Are the plans in public domain?  I needs a specialized grinder and would like to build one.


Google   'Hemingwaykits'


----------



## Steamchick

Hi  ENGINEMANPK. I agree. Alternative cuts to make a kerf - wider than the cutting blade - can alleviate some side stresses on the blade and workpiece (=heat) but when the parting blade is true to the alignment of the lathe (perpendicular to the axis) and the cutting end of the tool has no bias, I find it isn't  necessary. Try the hacksaw blade alignment to the chuck face that I showed in an earlier photo. The manufactured precision of the blade and un-used teeth give a visual guide that my old out-of-calibration eyes can see. But if you use a parting blade that has the top face angled away from the horizontal - per the wedge-clamp mounting in the holder, then the blade will develop side thrust and your trick will cause the cut to wander sideways. Been there and got it wrong!
But often we have to do what our tools and set-up will allow, and overcome imperfections and difficulties that the text-book in its perfect world  doesn't  consider. So thanks for the reminder/advice.


----------



## Steamchick

Richard Hed said:


> Just one question on that:  If you are going at a slower speed (revolutions/m), then are u slowing the engine or is it a geared (or belt drive) that is changed?  I'm wondering because it seems to moi, that a geared or belt driven system would have very high torque because it is still got the same horse power behind it, just going slower.  so each rev. may be take longer but the power, proportionally, should be much higher.  but if it is driven by Variable speed machine, then all bets are off.


Hi Richard, you are correct about the torque developed by the motor being translated by the gearing to a higher torque available on the wrapper at lower (geared) speed. Also, that some (not all) variable speed systems drop torque with motor speed.
However, in my badly explained diatribe, I was referring to the torque developed by the cutting (shearing) of material during parting -off. If you have a constant feed with (say) 1 thou per second feed, you will develop a certain torque at high spindle speed (thin swarf), but higher torque at lower spindle speed (thick swarf). My hands give a fairly constant speed of feed, not spindle speed related, as I do not have a power feed on the cross-slide. So I must be careful not the feed too fast when parting-off as on my small lathe I can stall the shaft (belt-slip). So it fails-safe. But on an older lathe I had, my hand-feeding could over feed the cut to the point where I could see the whole lathe twisting with the torque of the cut! It had a much larger motor and gearing than originally made. (And a ham-fisted operator!). Thus the torque developed by the cutting operation is higher when the cut is heavier...  as developed wth a slower spindle speed where the cut is not directly controlled by the spindle speed, all other factors beiing the same.
 I was simply trying t explain why, on smaller lathes, feeding the parting cut "hard" may not work because you can over-work smaller tools. I have seen many utube videos with experts using larger (stiffer) lathes with heavier cuts than I can consider on my small "hobby" lathe. 
Therefore ,  the amateurs seeking advice must be cautioned by experts, as to pitfalls that can mean working practices from one set-up cannot be applied to the other.
Sorry for any confusion...


----------



## BaronJ

Here you go Richard,  Well worth a read !



Richard Hed said:


> I am not familiar with the Worden.  Does u have a photo?  Are the plans in public domain?  I needs a specialized grinder and would like to build one.





			A Hacker's Guide to Building the Worden Grinder


----------



## goldstar31

BaronJ said:


> Here you go Richard,  Well worth a read
> 
> 
> 
> 
> 
> 
> A Hacker's Guide to Building the Worden Grinder



John

Don't get me wrong, it's a good write up but it is NOT the present Mark. I sort of guess it is Mark2 wheras mine is Mark3. 

Again, the Mark 3 will do the following- with attachments available separately and-- at more cost.
4 facet tool grinding
rounding off things like lathe tools
re-grinding slitting saws
using a diamond wheels

OK- I have seen it all before as I have the forerunner- the Kennet. Worth a look at Lathes.co.UK.

To sort the 'doers' from the 'talkers', there is the Quorn- now in its 3rd lease of life. 
That should keep Richard occupied- for years to come. Martins Models in the States also has castings

Bored- waiting for food and the arrival of a new set of castings for the GH Thomas parting tool kit etc

Cheers and that

Norm


----------



## holmes_ca

Steamchick said:


> Hi. I would still advise caution from my "Engineer's" head.... A bigger motor, or even  down- gearing, is seemingly a good idea because you ultimately want more torque applied. This is to overcome the shearing force exerted by the tool on the metal at the appropriate speed and feed of cut. 2 solutions, as the lathe (bed and slides) can only manage a limited torque. (If you don't  know, the cutting torque  is related to how much metal you remove = width and depth of cut, diameter at point of cut, and shear-strength of material being cut, so your lathe may be OK with a 0.0005in cut at 1in diameter, but not OK at 2 in diameter, or 0.001in cut because those both need twice the torque applied. Similarly a 2 mm tool takesc2/3rd the torque of a 3mm tool at the same diameter, feed-rate and workpiece material. )
> So:
> 1: reduce the feed-rate, or increase speed of rotation so each revolution cuts less metal (reduced cut = reduced torque to within the capability of the lathe stiffness).
> Or 2 : Reduce the width of cut - which is how a "Modified hacksaw" blade can work, when parting tools won't. Make a tool blade using a piece from a broken hacksaw blade - e.g. of un-used teeth just on the working side of the mounting hole. Select a tooth with a zero set as the cutting point. Make a precise holder so the blade is vertical. As the blade progresses into the cut the "kerf" from the set of the following blades will make the cut wider, but lubricate the cutting point as at the first tooth there is no side clearance - hence a lot of heat generated from the cutting shear, and side friction combined. I used this on a very small lathe, that had a big enough motor/gearing, but innadequate bed stiffness for cutting with my "regular" tool, on decent steel, at a larger diameter. But the feed was GENTLY, GENTLY! Not "stuff it in hard".
> Sorry to be so long winded, but it is a complex problem, and £10,000 of lathe will have a much better (easier) capability than a £500 "hobby" lathe. I have a variable-speed cheap Chinese lathe and it is great! For what it cost. But at low speed it has hardly any torque, so like the spring loaded tool holder, it naturally stops the cut if I am too forceful for the stiffness of the whole machine. Not a problem as I have the time to work carefully within its limitations, and my local club has bigger industrial machines when needed.
> Enjoy!



Steamchick, I do understand what you are saying but your post is too much for me to absorb at my age, I have done machining  professionally for over 45 years and another 23 years as a hobby, I realize that chunk of metal was too much for my little lathe and normally I would not attempt parting off a billet of that size, it just happened to be laying around and was convenient at the time, my preference would be to bandsaw it off to length first, that would be a faster and safer operation in my situation, and it might also be beneficial in eliminating a possible shattering of a larger parting tool on a larger machine that has more than enough torque and which more than likely has a geared head, that could be another part to the equation, I do depend a lot on my hearing with any type of machining, But I do understand the point you are making, 

Edmund..........Alberta


----------



## Balta

I have been toying with this idea for a while and finally got it done. The cutoff toll you see in the pictures is a piece of a woodworking carbide tipped saw blade. the holder is mild steel with a V grove top and bottom. Originally I was going to use a 60 deg dovetail cutter but the one I have is 3/4" and that would have been too big for the tool holder, so I ended up running a 6mm end mill holding the holder at 45deg (you can see this in picture "cutoff III"
Works like a charm and there is no chatter... and I haven't even ground the tip properly.
Incidentally, I paid $1 for the blade at a flea market and I have enough for several more.

Balta


----------



## OrangeAlpine

An interesting experience the readers of this thread might enjoy.

I did my best to incorporate the many suggestions, especially concerning rigidity.  Some  improvements, but not earth shaking.  The tool had a tendency to hog in and we all know where that ends.  

Fast forward to last week.  I tackled a project that required parting 1 1/16" water hardening drill rod (annealed state) drilled to 7/16".  I could see nothing good coming from this exercise.   But to my amazement, I encountered zero problems.  The tool would chatter (high frequency) for the first 1/16", then settle down to some steady cutting.    Made eight partings using hand drip cutting oil and never resharpening the tool.  About 75 rpm.  The water hardening drill rod is not an easy machining steel, but cuts cleanly, the chips were never a problem and it parts like a dream!  Much better than the leaded stuff that I had trouble with.

Who would have thought?


----------



## goldstar31

I think that the reason is that your technique has vastly improved.
Long may it continue
Regards

Norman


----------



## Steamchick

I agree with Goldstar. Also, you will now appreciate that the high frequency chatter is a cutting speed related phenomenon, as with the reducing diameter the cutting speed also reduced. I have a variable speed drive and a small tweak of reducing speed stops the chatter if I encounter any, then I always increase speed as I approach half diameter and below to "keep up a good cut". 
Keep up the good work,
K


----------



## Steamchick

That should read "increase rotational speed with reducing diameter" to "keep up a good cutting speed".
Sorry,
K


----------



## SmithDoor

Any update 
If you findcan books per 1925 It give how to  sharpen cutters. 
After that time they change the angle so ever one would buy new lathes and mills.

Dave 



OrangeAlpine said:


> What causes it?  I've made a very rigid parting tool holder that mounts directly on the compound and makes a very rigid setup.   Usually works like a dream, but sometimes get chatter.  It really seems to be a random event as it comes and goes with the same setup.  Sometimes touching up the tool helps, but not always.  The tool is spang on center and flat on top.  I've tried varying the grind angle, sometimes it helps, usually does not.  When it does  smooth the cut, the next cut may chatter.  Using a .090" wide blade.  Chatter starts the moment the tool touches the part.
> 
> Using a WWII era HSS blade.
> 
> Any suggestions?
> 
> Bill


----------



## goldstar31

SmithDoor said:


> Any update
> If you findcan books per 1925 It give how to  sharpen cutters.
> After that time they change the angle so ever one would buy new lathes and mills.
> 
> Dave



You are probably referring to Robert H Smith's Advanced Machine Tool Work( 1925)
Splendid book and available on the 'net.
Sadly in a fit of generosity I gave my coppy away

 However, I'm hanging on to my copies of the various volumes of Holzapffel. They 'say it all!
I mean where does one get a design for a honing jig-- or how to use sharkskin or a walrus hide?

The bit of 'Smith'  that I like is how to calculate how to hit a lathe tool angle using mathematics.
Oh, Hell, I've got a Quorn tool and cutter grinder which will do almost  everything apart from the tide tables in HongKong harbor-- but you get the idea.


----------



## mnay

"parting is such sweet sorrow"
Quote from a machine shop


----------



## goldstar31

mnay said:


> "parting is such sweet sorrow"
> Quote from a machine shop




'I am Chronicler'-----
Romeo and Juliet, please!

Shakespeare also wrote in Midsummer Night's Dream about ' Rude Mechanicals'

And All the World's a Stage and  all the men and women merely players. They have their exits and their entrances and -- one man in his time plays many parts--------------------------------

Exeunt!!!!!!!!!! Perchance to Dream


----------



## mnay

Shakespeare, Machinist?  Pretty close...………...


----------



## SmithDoor

I was look see the old old machine tools could cut and not chatter. 
I finely found in a old old book. It is the rake angle .
Even today the ads say low rake angle.

Dave 



goldstar31 said:


> You are probably referring to Robert H Smith's Advanced Machine Tool Work( 1925)
> Splendid book and available on the 'net.
> Sadly in a fit of generosity I gave my coppy away
> 
> However, I'm hanging on to my copies of the various volumes of Holzapffel. They 'say it all!
> I mean where does one get a design for a honing jig-- or how to use sharkskin or a walrus hide?
> 
> The bit of 'Smith'  that I like is how to calculate how to hit a lathe tool angle using mathematics.
> Oh, Hell, I've got a Quorn tool and cutter grinder which will do almost  everything apart from the tide tables in HongKong harbor-- but you get the idea.


----------



## Steamchick

Agree that a couple of degrees of rake helps, on my hand-ground tools. But with my long-blade-in-a-holder commercial tool, there is zero rake and sometimes that is best... why? I don't  know. But almost always when it chatters I can cut better if I withdraw the tool, slow down the motor by 20% or some and re-introduce the tool to the workpiece. I have cheated sometimes by cutting a mm or so with a hacksaw blade in the middle of the parting groove, then the parting cut works OK. I suspect because I have reduced the cutting load on the tool. Possibly why the commercial blade works, as it is narrower than my hand-ground tools?
But my final advice is "Sharp tools and wits, cut slowly and carefully, make good parts and bits"
K


----------



## goldstar31

Out of curiosity, just how wide is a  so called commercial blade?

I'm sort of amusing myself with access to a variety of tool and cutter grinders----- as my hacksaw is blunt

Next damn silly question is when does a normal lathe tool become a parting tool?

And what about this 'chip breaker' thing?

And when does one change  from a  10 degree grind to a 5 degree grind.

Ian Bradley in his ancient book on Lathes and Shaping Tools-- Oh yes, I have a copy- change to THREE angles in a lathe cuttig tool?  And Why?

Oh, yes

Of course, its an old book so what about grades of diamond dust paste?

Well the post has been drivelling on and repeat eating itself.

Clears throat--- WELL?


----------



## BaronJ

goldstar31 said:


> Out of curiosity, just how wide is a  so called commercial blade?
> 
> I'm sort of amusing myself with access to a variety of tool and cutter grinders----- as my hacksaw is blunt
> 
> Next damn silly question is when does a normal lathe tool become a parting tool?
> 
> And what about this 'chip breaker' thing?
> 
> And when does one change  from a  10 degree grind to a 5 degree grind.
> 
> Ian Bradley in his ancient book on Lathes and Shaping Tools-- Oh yes, I have a copy- change to THREE angles in a lathe cuttig tool?  And Why?
> 
> Oh, yes
> 
> Of course, its an old book so what about grades of diamond dust paste?
> 
> Well the post has been driveling on and repeat eating itself.
> 
> Clears throat--- WELL?



Hi Norman, Guys,

Well the only commercial parting blades that I have are 3/16 and 2 mm both 1/2" or 12 mm wide.  The only other parting blade that I have used is 25 thou and 6 mm wide.  Though in the past I've used Stanley knife blades and hack saw blades all with some success.  

As far as insert parting tips are concerned, I've seen them used but I've never used one.

When you get around to chip breakers and changing angles, I've always used two or three degrees of top rake and 7 degrees of front rake.  I've not altered them for years.

Best move I made for parting off was a rear tool post.


----------



## goldstar31

mThanks John for the details. 
I'm 'experimenting' AKA 'Fiddling on' with Chinese Deckel clone. Interesting beast

More Anon

Cheers

Norman


----------



## dazz

Hi
One of the main causes of problems with HSS parting blades is flank wear.  Both sides of the tool wear creating a wedge shape that is plunged into the work.  The wedge shape jambs into the parting groove leading to all sorts of chaos and mayhem.  
The solution is to either reverse taper the blade (wide at the tip, narrowing further back, or better still, use carbide parting tools.  

Dazz


----------



## goldstar31

dazz said:


> Hi
> One of the main causes of problems with HSS parting blades is flank wear.  Both sides of the tool wear creating a wedge shape that is plunged into the work.  The wedge shape jambs into the parting groove leading to all sorts of chaos and mayhem.
> 
> 
> Dazz



Respectfully, your comments fail to hold water. In all my years- well since the early 70's when Thomas wrote up in Model Engineer Volume 142 and I made up a  rear parting tool, I have NEVER had to regrind the flanks of my inverted tool.  I still---- HAVE THE SAME TOOL. I apologise for the shouting but no one is reading either my comments or more importantly, the book on which included Thomas's designs and thoughts. Again, a long established firm- Hemingwaykits  has not only continued to sell kits etc for the 7 inch lathes but has enlarged the drawings and casting to accommodate the same priciple for larger lathes.
ALL that has been necessary over these years has been to 'lick' the front of the tool.


 Me, well, I have bought a new set of castings to make another to go on the back of my other lathe- a Sieg C4. With tomgue in cheek, I actually bought another 'Model Engineers Workshop Manual-- and gave the very grubby one away to a member of this Forum.

So apart from the unfortunate creatures who do not have the facility to mount a rear parting tool, I cannot see that buying a book is so seemingly impossible.

So moving on a tad, I have 'done' a normal lathe tool on the Deckel copy thing and honed the 'little radius' with a 600 gret diamond 'stone' and am ready to further hone the corner with a white Arkansas stone-courtesy of my late wife. Yes, a black stone would have been marginally better.
well, I now have to have a jab in what is really my only slightly adequate eye.


----------



## johwen

John Here,
One thing i have found is that use the narrowest parting blade you can. I have a 1mm blade and a .5mm blade. i make sure that the blade is exactly at right angles to the work and the cutting edge is dead square. This eliminate any side thrust you can put a slight v in top cutting edge this will cause the chip to slightly fall in making it narrower than the width of cut and less likely to jam. I use my blade upside down so chip will fall away and not jam Lathe is o cause running in reverse and use constant feed pressure to stop chatter and if it is a large diameter I use power cross feed. make sure all your slides are of cause adjusted neat without any slack. This works for me i also use 'T" blades. My lathe is a Chinese same as Brian Rupnows


----------



## Steamchick

I have a home-ground WC tool on my rear tool post for parting anything up to 1/2in. Dia. But it isn't ground for deeper penetration. 0.1in wide. My commercial tool is 1/16" wide, and as a long blade in a holder can be extended to go deeper.. I have successfully  cut-off softer materials at 1 1/2" dia. Curiously, the top face of the long blade has a few degrees of side taper for the clamp in the holder. This hardly affects the cut, although I have been told to grind the top to a flat , but haven't needed to.
Incidentally, I parted some ordinary stock mild steel this morning, 1/2" dia, using my hand-ground tool in the rear tool post, starting at 350rpm, and increasing to 500 rpm at about half depth.  No problem. 
I wonder what speed all the experts would use?
Ken


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## Steamchick

The tool in the rear tool post is inverted so I run the "normal" direction.
This loads the saddle correctly to the design of the lathe.
K


----------



## goldstar31

Perhaps it should be mentioned that the GH Thomas tool will cut up to 2" in diamer.

But to muddy the waters somewhat the Late Martin  Cleeve wrote in Model Engineer that his Myford ML7 would cut 3" diameter stock 'faster faster than his machine hacksaw.
Now I should qualify the remarks and add that "Cleeve's machine was not a common or garden ML7 but had two motors driving line shafting and one motor was a full one horsepower.
 He wrote that his lathe saddle was a Myford 'special' and not cast iron but steel.

For those whoo posses his book 'Screwcutting in the Lathe' will note difference once surprise of his dog clutch  and a gear train which contained a transposing 127 tooth gear which was NOT the expected 20DP.
So it is all there but two things must happen.

One is the open one's pocket book and secondly actually test what both both writers described.

To muddy the waters further-- Cleeve( Kenneth C Hart) used a --- curved blade. He also increased the 'diameter' of the saddle handle---- and added his own power feed-- from the rear of the the lathe spindle.
As I wrote-- More Anon

Norman

Norman


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## OrangeAlpine

Reducing speed simply changed the chatter frequency, no impact on when the chatter stopped.  Oil seemed to make the operation go smoother.  Nothing really definite.  It seems that my lathe (12" Enco, belt drive) crossfeed is too fast, have to do all parting using manual feed.  You can say my improved results are due to my improved technique, if so, then tell me how my improved technique totally eliminated chips as an issue.  

I did use a different chuck, a 6" monster instead of an effeminate 5 inch.  I will look into this as a possible factor.  

I hope you can see pics of my parting tool holder.  It is made of various mystery steels, the tool is .090", industrial refuge from 60+ years ago.


----------



## BaronJ

dazz said:


> Hi
> One of the main causes of problems with HSS parting blades is flank wear.  Both sides of the tool wear creating a wedge shape that is plunged into the work.  The wedge shape jambs into the parting groove leading to all sorts of chaos and mayhem.
> The solution is to either reverse taper the blade (wide at the tip, narrowing further back, or better still, use carbide parting tools.
> 
> Dazz



Hi Daz,
I'm sure that you will be aware that a lot of parting blades have a tapered cross section that intended to be used in a specially made holder that compensates for the taper by holding the blade truly vertical.  The use of one of these blades in a normal holder causes the blade to be slightly lent to one side !

This means that the blade will try to twist as the cut gets deeper and will jam or in severe cases break.

All the parting blades that I have and use are parallel sided, they have a rectangular cross section.  In a normal holder this ensures that the blade will be held truly vertical.  I can and have parted 60 mm stock with a 2 mm thick blade, but it is vital that the blade is set dead square to the chuck face.


----------



## goldstar31

When I bought my 2nf casting kit, I wanted Hemingwaykits to supply both blades( as BaronB suggests)

Alas and alack,  the narrower blade is not available at the same width as the thicker one.
So Thomas's split - clamping turret has to be altered. Unless I have a magnetic table and a Clarkson grinder to reduce the thickness.

All go, but then I have to grind the 140 degree kerf along the 'top' which is upside down of course.
Once all this malarkey is done, it only requires a like at the front. None of this fiddly and faffing which is a continuous time waster-- with indifferent results--  as I read happens.

You see I have a professional jig to alter the shape of grinding wheels ---as supplied.

And we haven't got round to that yet.
Perhaps more anon? Be patient as I have THREE air bubbles in my injected eye.  Still it can't be bad as as the injector lady gave me a magnifying torch and - a great big stand to put books and. plans under neath.
Oh and and a new face mask. 
I never thought that really old people were  treated with such courtesy !
So I'm waiting for the black spots to go


----------



## Ken I

As Goldstar states the holder must have a matching angle to hold the blade truly vertical with the clearance equal on either side.
When you hold a commercial blade horizontal then any required rake has to be ground at the cutting edge.
The double bevel on the top edge is meant to narrow the chip - so you are not really supposed to grind it away - instead the blade should be held in a holder that inclines the blade to the rake angle.




Re: Above Images :-

Top :-      Blade horizontal - rake ground to remove double bevel - no more !
Middle :- Blade horizontal - rake ground below bevel - parting depth now limited to where the blade widens.
Bottom :- Blade inclined to rake angle - you only grind front clearance - leave double bevel as a chip "folder".

This makes the chip narrower than the cut and helps reduce hogging. It also makes resharpening simple and consumes less blade.

Regards, Ken


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## goldstar31

Thanks Ken

If you grind a vee- or perhaps easier- a rounded kerf, the inverted tool should cut-- and roll the narrowed swarf-- into little ccurlies. 

Cheers and Thanks

Norman


----------



## Ken I

Thanks Norman - I should have mentioned that - for flat blades I do it on the edge of the grinding wheel or with a Dremmel - like you say "curlies"

Regards, Ken


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## ShopShoe

Norman,

I just gotta tell you that I do read and appreciate your posts. I also appreciate that the ones who have gone before have had a lot of good advice that we should consider before the "Woe is me....."

I am also inspired that you keep going despite whatever life throws at you.

--ShopShoe


----------



## JRSherbundy

goldstar31 said:


> When I bought my 2nf casting kit, I wanted Hemingwaykits to supply both blades( as BaronB suggests)
> 
> Alas and alack,  the narrower blade is not available at the same width as the thicker one.
> So Thomas's split - clamping turret has to be altered. Unless I have a magnetic table and a Clarkson grinder to reduce the thickness.
> 
> All go, but then I have to grind the 140 degree kerf along the 'top' which is upside down of course.
> Once all this malarkey is done, it only requires a like at the front. None of this fiddly and faffing which is a continuous time waster-- with indifferent results--  as I read happens.
> 
> You see I have a professional jig to alter the shape of grinding wheels ---as supplied.
> 
> And we haven't got round to that yet.
> Perhaps more anon? Be patient as I have THREE air bubbles in my injected eye.  Still it can't be bad as as the injector lady gave me a magnifying torch and - a great big stand to put books and. plans under neath.
> Oh and and a new face mask.
> I never thought that really old people were  treated with such courtesy !
> So I'm waiting for the black spots to go


Sorry to hear about the air bubbles in your eye.  I am setting here now with one bigger bubble in my right eye.  Been there since August 20.  On that date, the entire eyeball was one big gas bubble.  It is getting progressively smaller.  Sometimes the bubble breaks up into two or more smaller bubbles.  Only happened once this time.  Same problem happened to same eye seven years ago.  That time the bubble would break up into many smaller bubbles often.  Finally the bubble is small enough I can see over (really under the bubble, just looks like it is over.  Still a giant pain.  Depth perception is worthless, so using and applying cutting or drilling tools is a hit or miss proposition.  Nice thing is no more black spots since when they took all my existing eyeball juice, the black spots were removed as well.  For seven years I had this big monster floating around in there.  Gone now.  Looked like one of those Space Nebula things you see in those outer space pictures.  So my advice is be careful.  Aim twice, apply cut once.


----------



## goldstar31

Thank You, Sir, for your 'clear insight' despite what to others and myself seem impossible to comprehend and we wonder just how you can cope.
Coping with advancing age and deteriorating health is, as you well know, a difficult task. Moving to more private things, I've just been stunned to learn of the untimely death of a friend's wife and yet another phone call to learn of heart problems of yet another long friend. It's not easy to know what to say.

Moving further away from our happy hobby, we must not only be cognisant of a difficult world that many have no alternative but try to endure but to actively try in our own individual ways to try to eradicate the suffering of others.
Perhaps, I should say that the first  to put others first- instead of our own selfish desires.

I recall those three words from the Acts of the Apostles and realise that other Faiths share the same aspirations .
I leave you Sir and all others with the concept of 'Faith, Hope and Charity'  realising that we all have to endure extra problems again escalating in every part of the World.

So may I try humbly to emulate those strictures and look forward to a better New World for all of us- and those who follow on.

Most sincerely and as some of us say'I greet you well'

Norman Atkinson


.


----------



## dazz

BaronJ said:


> Hi Daz,
> I'm sure that you will be aware that a lot of parting blades have a tapered cross section that intended to be used in a specially made holder that compensates for the taper by holding the blade truly vertical.  The use of one of these blades in a normal holder causes the blade to be slightly lent to one side !
> 
> This means that the blade will try to twist as the cut gets deeper and will jam or in severe cases break.
> 
> All the parting blades that I have and use are parallel sided, they have a rectangular cross section.  In a normal holder this ensures that the blade will be held truly vertical.  I can and have parted 60 mm stock with a 2 mm thick blade, but it is vital that the blade is set dead square to the chuck face.


Hi
That is not what I mean. Flank wear tapers the blade width.  Close to the cutting edge, the blade wears narrow.  Moving back from the cutting edge, the blade is wider (not worn).  The result is a fine wedge that jambs in the cut slot.

Dazz


----------



## jack620

dazz said:


> Hi
> That is not what I mean. Flank wear tapers the blade width.  Close to the cutting edge, the blade wears narrow.  Moving back from the cutting edge, the blade is wider (not worn).  The result is a fine wedge that jambs in the cut slot.



What you state makes perfect sense- in theory. In practice I’ve never experienced this, nor have I ever read about it in any of the lathe “bibles”. I suspect that any wear on the sides of the blade is so miniscule it is more than compensated for by the fact the blade gets shorter as it is sharpened.


----------



## goldstar31

I have the same 3/32" blade inserted in 1973. The front IS wearing and is repeated reground-- and because it slopes is getting very near to  being unable to cut 2" diameter stock.

It's Euclid. for those who missed his propositions  at school missed a very valuable contributor. How sad!
But then he only worked in 2D


----------



## johwen

Yes 1. put a small top groove in the blade to collapse the chip so that it does not drag in the groove. 2. make sure the blade is at right angles to the work. 3. make sure that cutting edge is square to the blade otherwise the too can drift sideways in the groove and if it is a deep cut can drag in the groove. 4. use a quality cutting oil on the blade. 5. if it is a deep cut in larger diameter work take a second cut opening up the groove. These are my tips for successfully Parting. If chatter is still a problem try using a narrower blade. Happy parting and stay well.
John


----------



## Steamchick

Hi Dazz, I have experienced a similar effect with worn twist drills. The "Old-and-trusted" and many-times re-sharpened drill simply binds when used for a deep hole, where most of the previous drilling - and wear - has been on shallow holes. A micrometer can barely detect the wear, but it is significant and"destroys" any chance of a precise drilling when it starts the "screaming" as un-worn flank tries to ream the holes where the worn drill has left a fraction of a thou of metal. - Time to replace the drill bit! (I worked out the 3/8th in drill bit was bought around 1980! It now has a bit of tape telling me how deep I can safely drill without binding!).
K


----------



## Steamchick

A "parting" shot:
"Slowly solowly....    Speed kills!"


----------



## BaronJ

jack620 said:


> What you state makes perfect sense- in theory. In practice I’ve never experienced this, nor have I ever read about it in any of the lathe “bibles”. I suspect that any wear on the sides of the blade is so minuscule it is more than compensated for by the fact the blade gets shorter as it is sharpened.



I must admit that I've never experienced this phenomenon !
All but one of my parting blades have parallel sides.  I would have thought that if your theory was correct, then I would have run into difficulty long before now.

As said in the quote above, any microscopic wear on the side of the blade would be removed when it was sharpened.

I did a test by swiping a red marker pen across each side of the tip of the blade, the marker only got wiped very slightly on the chuck side, but I put that down to grinding the cutting edge slightly off square or the blade being not absolutely vertical.


----------



## BaronJ

Steamchick said:


> Hi Dazz, I have experienced a similar effect with worn twist drills. The "Old-and-trusted" and many-times re-sharpened drill simply binds when used for a deep hole, where most of the previous drilling - and wear - has been on shallow holes. A micrometer can barely detect the wear, but it is significant and"destroys" any chance of a precise drilling when it starts the "screaming" as un-worn flank tries to ream the holes where the worn drill has left a fraction of a thou of metal. - Time to replace the drill bit! (I worked out the 3/8th in drill bit was bought around 1980! It now has a bit of tape telling me how deep I can safely drill without binding!).
> K



Hi Ken,

I've noticed that, particularly on older drills that don't have ground flutes and some cheap Indian drills that I should have avoided !

The effect is worse with drills that I've reground 4 facet.  Having the lips very slightly unequal stops the binding because the hole is a fraction larger than the drill.

Of course this also assumes that the drill isn't bent, or that the drill is blunt and enough pressure is used to force cutting and causing the drill to bend whilst drilling, which will cause the drill to wander off in a deeper hole.


----------



## goldstar31

As the 'bibles' have been quoted, I've forgotten TWO. Well, I'm 90 and have success in parting off.
Suffice to say that I've written about it more than enough.
The origin of the one by G H Thomas is merely a development of a very successful model engineer who wrote under his own name and and with a Dr Norman Hallows as Duplex. Bradley wrote a trilogy on the Myford lathes but prior to this wrote a definitive book on  tools for the lathe and shaping machine as well one on the Drilling Machine, the Shaping Machine itself. His book on grinding machines preceded everything. Fairly impressive, but turn the clock back to 1948. I was running a Technical Library in the Royal Air Force( Oh  Yes, it's a non commissioned fitter's job- and I certainly was an aircraft hand general duties - the lowest of the low) and out of my miserable pay bought Leonard Sparey's  The Amateurs Lathe.
Yes the  rear tool post with the sloping inverted was- and I still have it- is in there. 
It is still a recommended read whilst his 'engines' are built and copied yet.

Postulate if you must but 'it was ALL THERE then


----------



## dazz

jack620 said:


> What you state makes perfect sense- in theory. In practice I’ve never experienced this, nor have I ever read about it in any of the lathe “bibles”. I suspect that any wear on the sides of the blade is so miniscule it is more than compensated for by the fact the blade gets shorter as it is sharpened.


Hi
It is a practical problem.  I have experienced this with HSS blades.
I avoid the problem by using carbide tooling.

Dazz


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## goldstar31

dazz said:


> Hi
> That is not what I mean. Flank wear tapers the blade width.  Close to the cutting edge, the blade wears narrow.  Moving back from the cutting edge, the blade is wider (not worn).  The result is a fine wedge that jambs in the cut slot.
> 
> Dazz



I'm pretty sure of what BaronB has- and what standard he is capable of grinding to. He designed his own home brewed tool and cutter grinder. I have a Quorn which is capable of some very fancy grinds both in HSS and - with a CBN or diamond wheel, it can happily tackle the differences in angles--- and being able to precisely 'round off' the two cutting edges in  lathe tools. The Quorn user's group has been going great guns on this topic.
So with a sort of return to what passes for eyesight, might I ask what or how the many correspondents have tackled the problems which have given them the experience to advise.

Me? In the dim and distant past I was not only a person who was making/modifying resins and - you will have to laugh- a shareholder in a failed local grinding machine manufacturer 

Over to others- thank you

Norman


----------



## stackerjack

BaronJ said:


> Hi Norman, Guys,
> 
> Well the only commercial parting blades that I have are 3/16 and 2 mm both 1/2" or 12 mm wide.  The only other parting blade that I have used is 25 thou and 6 mm wide.  Though in the past I've used Stanley knife blades and hack saw blades all with some success.
> 
> As far as insert parting tips are concerned, I've seen them used but I've never used one.
> 
> When you get around to chip breakers and changing angles, I've always used two or three degrees of top rake and 7 degrees of front rake.  I've not altered them for years.
> 
> Best move I made for parting off was a rear tool post.


I bought some nice inserted parting tool bits. The first time I used one it flew out of it's holder, and I haven't seen it since.


----------



## stackerjack

I agree with Dazz on the parting tools being tapered. Lots of books advise this method. However, when you buy a new parting tool it it always parallel. I find the thinner the blade, the better.
Jack


----------



## goldstar31

stackerjack said:


> I agree with Dazz on the parting tools being tapered. Lots of books advise this method. However, when you buy a new parting tool it it always parallel. I find the thinner the blade, the better.
> Jack


According to 'Sparey', his tapers were 2 degrees on each flank. Mathematically, one loses a great deal of metal in subsequent re-sharpening.  The next question is how does one grind two degrees?
Yes, I CAN do it but as I have the tools to do it- some bought, some I made but how does a beginner achieve it- with limited facilities?  Really that is what the forum members ask-- and we try to answer.
As a sort of follow up, Sparey for one senior expert in such matters describes EIGHT standard lathe tools- including one to part off and not including boring tools.
His quoted angles were  5, 55,7,12,30, 2, 45 degrees and rounded noses of 1/16"th and 1/8"th!
The book, I must repeat is or was 'the Amateurs Lathe'

I made a comment but haven't dared print it
N


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## ajoeiam

Steamchick said:


> A "parting" shot:
> "Slowly solowly....    Speed kills!"


Dunno about that - - - - especially in parting faster gets you far better chip control the smaller the diameter - - - its that last 1/8" of cutting that's such a pita! 
Been more than once I stopped the machine before the cut was done - - - - it seemed safer to just break off the part!


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## Steamchick

Mathematically, the theory says that the metal is at zero speed when you get to the centre of the parting cut. So (I think) a continuing cut will always reach some point where the metal is too slow to cut properly, and the torque required more than the tiny stem can resist, so it always breaks the last smidgen anyway.
When u you say you go faster to improve chipping, are you referring to rotational speed or feed? Maybe it's the cutting angles on my tools, but I don't  get chip problems. I do cut a bit then back-off for cooling, for a second every few seconds, but that's because I cut dry  most times. I'm retired so  slowly occupies my time better than rushing breaking and remaking bits.
Enjoy making swarf! However you do it.
K


----------



## goldstar31

As far as theory is concerned, I have passed that and for more years than I wish to recall, I CAN PART OFF SUCCESSFULLY.
The only possible problem which could  arise is  that the part -  parted off will nip between centres.
None of these 'taking endless bites of the cherry' and that plunge cutting and starting a new cut and all sorts of variations which would baffle  . Paganini.  My set up is designed to part off TWO whole inches in diameter- and that's it.  Enough to say that I have another lathe-- and have the casting to make another satisfactory parting tool.  All That I have to do is put a sub plate under the thing and chew a few millimetres off the casting 'foot'


----------



## Steamchick

Hi Goldstar. Good. I'm glad to hear that so many of us are capable of this particular operation. But (in my case) - I don't understand what I am doing well enough to know why it is easy for me and not for others? Maybe I am wrong in what I am doing, and would get better results from following others' advice, but this thread seems to cloud the issue with many saying that they have done "everything" and fail to be happy with the results. The only thing I have really spotted is that many seem obsessed with speed of parting-off, whereas I was taught (in the 1960s) to "slow down boy!". A bit slower often produces better results than "forcing" cuts to their limit.
So all I have been doing is throwing my pennorth of experience into the pond, hoping someone will find and use the treasure one day.
Sorry if I upset you? - Not my intention.
K


----------



## goldstar31

Ken
Thanks for the explanation and if I am  a bit critical of things, I apologise as a crusty old ninety year old- who certainly wasn't an engineer
I realise that  model engineering is really an insignificant part of   a real world. 
As far as eradicating the myth of difficulties in parting off, I spent £30 or so and the cost of a couple of blades-- in 1973. I passed the aged manual to a member here after buying a clearer one.  I still have the rear tool  and bought a spare blade as replacement was imminent.
So arithmetically( I took top marks in Cost Accountancy, long before  I retired for longer than I ever worked) I don't think that lost in time and in expence in the pursuit of a hobby.  If you think about it, the cost -- so far- is piffling on an annual basis.

Putting it into a simpler understanding- I paid out less in almost half a century LESS than a bottle of cheap whisky- which was gone in a night 

Norman


----------



## Steamchick

Hmmm. Maybe I was over-reacting a bit as well... Sorry Norman. 
I don't want to "compete" with that, but I made a rear tool post from a scrap off-cut from a sash weight (HORRIBLE steel - possibly ex-Battleship armour? - A lot of which went into the melting pot after the First World War?), and a simple tool post from a rectangular block of iron, with a High-speed steel tool ground to suit a traditional parting tool shape.... Cost = piffling (but who cares?), and it is arranged with a clamp such that if there is an overload, the tool post "slips" and releases the cut. It isn't the stiffest mount, but works fine for me... But maybe my crude version with a "slow and careful" cut doesn't suit everyone's style? As I am not designing tooling for high volume production it matters not a jot to me, as long as I am happy with the activity and results are good enough for my models. 
But I do like to learn from all the expert machinists that write on this website. 
Incidentally, as I just grind tools "by hand and eye" - the various tool angles are wherever I happened to hold the part against the grinding wheel, rather than anything exact or calculated. (after 50 years it seems natural). But my tools look a lot like the sketches in such books as "the Amateur's Lathe". I'm sure I had something like it, but I passed on my books to a friend who inherited a lathe and had zero training or background in "workshop tool and machining practice"... When I forget what I am doing I won't need to refer to the old text books, but till then.... this website is interesting. 
Thanks,
K


----------



## goldstar31

Well we've digressed somewhat but parting off has been flogged and flogged not just now but several times earlier and sadly - got nowhere really.

So let's deal with Three similar problems and attempt to find WORKABLE answers?

The First is 'your window weight in cast iron'.  i agree with every word and suggest that you nget rid of the sand-- from where your German battleship settled in the sand in 1917 in Scapa Flo.
First heat it up red hot- perhaps on the barbecue and leave it overnight to get rid of the hardened 'skin' with some of the sand attached/embedded.
Then dunk it in what you can get- battery acid, drain cleaner or vinegar, the remain of the pickle jar  or any cheap acid-- even your vomit. I jest not- all will work
Then hitting the right angle from a perhaps 6 inch grinder. Let's say that you want a 7 degree angle?

Multiply the 6 inches by 7 degrees and multiply it by a secret constant of 0.0088. and you get 0.369 and call it thousands of an inch.  The nearest usable figure is 0.333" or a third of an inch. If you build up a wooden/plywood 'grinding table' to be that third of an inch from the centre of the wheel--- you have a grinding angle of 7 Degrees.  It's taken me  longer  to type it than do it. It's what the 'greats' tell you but put it oion a list to hide how simple it all is 

And now - between phoning a 'girl friend' and accepting an offer to quaff a whole bottle of Scotch with a mate- I hit trouble with a cheap and not very nice 4 jaw SC chuck which I finally wanted to use. 
Everytime she walks she wobbles--- moving pictures. So what to do? Well, Martin Cleeve,authour of Screwcutting in the Lathe and Professor Dennis H Chaddock author and designer of the Quorn tool and cutter grinder came up wit a solution without buying a GripTru chuck.  So far, I stripped the chuck off the Myford backplate and did a facing cut of the plate including the register-- and put it together. The wobble was gone but the jaes were a gnat's cock out.  So far so good- a man on a motor bike would never see it.
But these two worthies got closer to 'concentricity' so my next job-- assuming that I will be sober tomorrow, is to  remove a bit of the register on the backplate so that the chuck with its 4 bolts could move if altered.  So I'm going to overbore the holes in the chuck-- so that a chuck is just tight enough o be clocked to run true- with the judicious application of a hammer.
OK if the jaws are still out a bit, I did mention the use of va Bosch POF 45 wood router.

As they say, meanwhile back on the ranch. Hope this all helps

Norman


----------



## justisla

goldstar31 said:


> As they say, meanwhile back on the ranch. Hope this all helps
> Norman


Not really-- I do not have a clue what you were trying to say


----------



## ajoeiam

goldstar31 said:


> As far as theory is concerned, I have passed that and for more years than I wish to recall, I CAN PART OFF SUCCESSFULLY.
> The only possible problem which could  arise is  that the part -  parted off will nip between centres.
> None of these 'taking endless bites of the cherry' and that plunge cutting and starting a new cut and all sorts of variations which would baffle  . Paganini.  My set up is designed to part off TWO whole inches in diameter- and that's it.  Enough to say that I have another lathe-- and have the casting to make another satisfactory parting tool.  All That I have to do is put a sub plate under the thing and chew a few millimetres off the casting 'foot'


I won't suggest that parting off 2" dia is nothing but it really isn't a large cut. 
When you part off even a 2" dia piece it is important that you 'catch the cutoff - - - - if you aren't stabilizing the piece and it starts to wobble - - - well it can take out not only the part off tool but can drag the piece right out of the chuck - - - - things get interesting then - - - - NOT a lot of fun though!
I've found trying to using a parting tool on the end of the piece can get very challenging. 
In this case the smaller the diameter the tougher it gets.


----------



## goldstar31

I'm repeating myself. 

Others on the 'net have also written and written.


----------



## goldstar31

justisla said:


> Not really-- I do not have a clue what you were trying to say



For those who are following this saga,  I checked the drawings for the newer rear tool post from Hemingway kits and found that the turret which hitherto had taken two parting tools has been altered to take one but the other part of the holder actually holds an inverted conventional lathe tool- upside down of course. 
My immediate thoughts were 'why is lathe tool not inclined' It would have saved a lot of grinding for those who find it difficult.
No, I am NOT confusing the issue but merely reporting what was created by others.  
Of course, I have the Quorn which is- with the introduction of the Mark3 from Hemingwaykits seemingly easier- Ye Gods?- it is not only confusing for mw who built one- a Mark1- but the kit price is almost as dear as the Chinese Deckel/Alexander clone which is complete- ready to perform- that is if you can understand it. Again, I'm not theorising, I have one.


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## Steamchick

Hi Goldstar,
On the sash weight material, After heating in a muffle furnace, to a nice red glow, the round weight was "D" shaped from softening with the heat. (Left inside the muffle furnace to cool slowly). So hitting parts of it with a centre punch, in some places nice and soft, but in others, the centre punch was the "soft" metal! Cutting with an angle grinder meant that the sparks changed at various points of the cut, as zones of different hardness steel were passed.... I wrote off one angle grinder as the steel in one zone was simply to hard... the carborundum didn't touch it and the motor burned-out, with the grinding disc glowing red on the edge...
So it makes a good weight to hold jobs steady when I have a blow-lamp job to do...
On grinding tools "by-hand" - I do have a few pieces of hard wood spacer that I put on the rest to elevate the work-piece to give an angle that I want against the stone. And another grinder has a sloping tool-rest to give yet another angle setting. And I made a jig for re-grinding bits for a Diamond Tool holder that I made.... But measuring 7 degrees, as opposed to 6 or 8 degrees, on the end of a tool with an engineers' protractor isn't as accurate as having a precision tool grinder. But I am happy with the tools I make, for the work I do. (It's what I was taught by the time-served machinists in the 1960s in a machine-shop where I worked).
And thanks for the advice on projecting angles and the use of geometry, that was good new information. Curiously, my wooden spacer on the grinder is 3/8" thick above centre - which is pretty close to your 7 degrees angle...


----------



## Steamchick

Wow! - Just looked on £buy and the tool and cutter grinders are all professional bits of kit - mostly in the thousands of £... just a few in the mid~high hundreds of £. I.E. Worth more than the rest of my workshop. - Yes, I am a penny-pinching pensioner. So I'll stick to my "hand" skills on my £20 grinder.... suits my needs. Thanks for all your advice anyway.
K


----------



## goldstar31

Steamchick said:


> Wow! - Just looked on £buy and the tool and cutter grinders are all professional bits of kit - mostly in the thousands of £... just a few in the mid~high hundreds of £. I.E. Worth more than the rest of my workshop. - Yes, I am a penny-pinching pensioner. So I'll stick to my "hand" skills on my £20 grinder.... suits my needs. Thanks for all your advice anyway.
> K



Ken 
Thanks for the reply. Glad to have helped another 'penny pinching perisher'. 
I paid rather more than you for a 2nd hand Clarkson. It was all of £100 and after I nhad built my Quorn from castings- I needed a better motor than the one from a scrap washing machine. I followed up an ad for one and 'parted' with £100 and came home not only with the motor but a complete Stent tool and cutter grinder which in my opinion- is more versatile than the Clarkson.
5 Yesars ago, I'd been virtually bankrupt at the time my wife suddenly died. By a rather nasty stockbroker and when things returned to 'normal'I bought a Chinese thing as a sort of something to occupy vast swathes of being alone. Of course, Covid-19 has only made things worse but I'm actually accruing money.
Returning to cast iron window weights, I had much the same dreadful problems.  Life was improved with the purchase of a once useful marking out table which I bought for £3. It turned out to be Meehanite !
Joy unconfined!
As for HSS and welded carbide tools, these were bought for very little. 
As for  your £20 grinder, my experience was to throw the rests away and also buy proper cool running wheels which will produce almost mirror reconditioned tools in hss and I bought a diamond wheel or two to mirror finish both hss and carbides.
So sometimes I spend money recklessly and others - more than carefully

So kind regards, keep well

Norman


----------



## djh

This is my first posting on this site and I would try if you havnt got a rear toolpost lot of people havn't, front toolpost. tool upside down machine run in reverse,  but i have never had any problem with chatter or the dredded snatch providing you use the tailstock to support the work use a running centre if you can just forcing the centre in will be sufficient or a flat support in a chuck maintaining pressure as you cut and if your machine slide is loose just locate one jib screw and tighten as you cut and loosen when you have finished.
The old machinists used to have parting tool holders with a spring slot almost all the way thru but ive never liked them so never used them.
hope this helps someone.
David(djh}


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## goldstar31

David

Welcome to the Forum. I hope that you will enjoy the communications.
Whilst I  have a rear parting tool holder( A GHT one) for my Myford Super 7B PXF,  I have no problems with parting off from the front of my Sieg C4 using the parting tool in a similar way as a conventional lathe tool.

Me  thinks  it is 6 of one and a half dozen  of the other!

As for the spring tool thing- beloved of a past generation,  at 90 years, I had  one for parting and another for fine finishing.  The snag is that mine were fashioned on the anvil from carbon steel and then tempered. 
That means that using carbon tools results in far quicker wear and in any event now, I can achieve a finer finish using my own ground HSS blanks.

At one time- or should I say before 1973, tool and cutter grinders were nigh impossible to have whereas, there are both second hand professional ones and also  designs and kits to make them.

For those who are interested Ian Bradley wrote it all up in his somewhat dated Lathe and Shaper Tools book and also the Grinding Machine which is even more archaic. I'm archaic too.

My view on things?

Best wishes

Norman


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## goldstar31

Going through what has to pass as my memory, I began to  recall that Mosel Engineer magazine published another rear  parting tool which had an adjustable tilt. No idea but it may jolt another memory. This lead me a more modern parting tool gadget but like David's references to earlier tools was made with a mild steel body but it was 'split to allow it  to go out of cut if circumstances went wrong. I saw it, was amused but again someone might expand the topic.

Going back over a number of years, I mentioned and interesting series of articles by a Conrad Hoffman who with his his wife wrote a series of articles- still on the 'net but called 'The Messy Basement'.
Having read how peole here here manage to sharpen tools,  might I  repeat Hoffman's  Advanced Tool Sharpening for the Lathe- with special emphasis on Threading Tools.

It does deal with carbide tools as well as hss stuff and whilst I may not totally agree with it, I did find it stimulating.
For those who are history buffs,  it suggests a modern version of the Goniostat which first appears at the beginning of people like Maudsley but was for something called 'Ornamental Turning'

Yes, a mate of mine made a Goniostat
Enjoy?

Norman


----------



## BaronJ

Hi Norman, Guys,

Not quite on topic, but I thought that Norman would like to see what has happened to the motor he so kindly passed on to me !













These pictures are of the work head of the tool and cutter grinder that I'm building.  My design of the grinding spindle cartridge is in the carrier.  The cartridge is 30 mm diameter with a 12 mm spindle.

Though you can't see it the end caps which are threaded contain the pair of Teflon labyrinth seals at each end


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## goldstar31

BaronJ

I'm glad to see that it has finally become useful again.

Regarding the spindle, the labyrinth seals to exclude dust are impressive.


Oh and more plans are afoot( or 12 inches)
More Anon.

Regards to All

N


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## BaronJ

goldstar31 said:


> BaronJ
> 
> I'm glad to see that it has finally become useful again.
> 
> Regarding the spindle, the labyrinth seals to exclude dust are impressive.
> 
> 
> Oh and more plans are afoot( or 12 inches)
> More Anon.
> 
> Regards to All
> 
> N



Hi Norman, Guys,

Thankyou for the pat on the back ! 

Those tiny Teflon ring seals were quite difficult to make.  They are only 1 mm thick 18 mm diameter with a 14 mm bore running in two grooves 1.5 mm wide and 2 mm apart.  They grip the support sleeve quite nicely.


----------



## Noel Gordon

Just some interesting thoughts guys..NO diy machinist should ever need to use carbide tips and should learn how to use HSS this way you will eventually understand about cutting angles and how to use HSS to its max. I have been a toolmaker for the last 60 years and as an apprentice was not allowed to even whisper the word "carbide" and I was not thought about carbide until my 5th year.
I remember telling my boss that I could cut a piece of 4inch ms shafting in two in the workshop power hacksaw faster than he could if he was using a parting off tool,,I then stood and watched him part the shafting in two and the realized my power saw was ONLY half way through...In more than 60 years I broke a parting blade in my first week but that is the ONLY blade that Ive broken in more than 60 years..but Im NO hero but I was just tort how to use one correctly ..Guys STOP over thinking things and just DO IT>


----------



## Steamchick

Fair comment Noel. I agree that with a good a the and correct speed and sharp tools lathe work is easy, but if some are using "lightweight" hobby lathes and "tiny" tools then special care needs to be taken to cut with the capabilities of the machine. Although I used an 18 in swing lathe machining cross-heads 10 in diameter for Broom Wade compressors as a teenager, it was a different job machining parts 1/8" dia. in my Dad's 1930 3 in lathe powered by a Singer sewing machine motor. When I inherited that lathe he had converted to a quarter horse motor, and parting 1 in cast iron you could see the bed of the lathe twist with the torque through the back-gearing! So SLOWLY AND CAREFULLY CATCHEE  MONKEY! Using the correct application of force on each tool is what we learned as apprentices but is a "black art" to many readers of these threads. So a little patience and we can help them with our skills and knowledge.
Thanks for your help. - As an Engineer, I have worked with some of the best skilled people and love to learn their skills - to improve my amateur work.
K


----------



## Steamchick

Sorry, I didn't   manage to overcome all the spellchecker quirks. It hates "lathe",  and changes it into "a the"...
K


----------



## RM-MN

Noel Gordon said:


> Just some interesting thoughts guys..NO diy machinist should ever need to use carbide tips and should learn how to use HSS this way you will eventually understand about cutting angles and how to use HSS to its max. I have been a toolmaker for the last 60 years and as an apprentice was not allowed to even whisper the word "carbide" and I was not thought about carbide until my 5th year.



Yesterday I tried to modify a single point threading tool to bring the point nearer the edge to facilitate threading up to a shoulder.  My eyesight isn't as good as it was 40 years ago and I speny half an hour with my under powered grinder trying to grind away the unwanted metal only to end up with a point that was not 60 degrees.  For $10 I could have bought a carbide insert cutter and for another $10 I could have bought 10 new inserts.  All of them would have had the right angle on them and could cut up to that shoulder.  If I damage one, a 20 second switch to another insert and I am ready to go again, no grinding necessary.  The quality of carbide has improved over time and I find that the inserts I just bought leave a better finish than I can achieve by grinding HSS.  I can also cut harder material than HSS is capable of.


----------



## BaronJ

Steamchick said:


> Sorry, I didn't   manage to overcome all the spellchecker quirks. It hates "lathe",  and changes it into "a the"...
> K



Hi Ken,  I'm having problems editing my posts !


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## BaronJ

RM-MN said:


> Yesterday I tried to modify a single point threading tool to bring the point nearer the edge to facilitate threading up to a shoulder.  My eyesight isn't as good as it was 40 years ago and I speny half an hour with my under powered grinder trying to grind away the unwanted metal only to end up with a point that was not 60 degrees.  For $10 I could have bought a carbide insert cutter and for another $10 I could have bought 10 new inserts.  All of them would have had the right angle on them and could cut up to that shoulder.  If I damage one, a 20 second switch to another insert and I am ready to go again, no grinding necessary.  The quality of carbide has improved over time and I find that the inserts I just bought leave a better finish than I can achieve by grinding HSS.  I can also cut harder material than HSS is capable of.



Hi,
Yes I came to the same conclusion some time ago for very similar reasons.  I also try to cut threads away from the chuck, particularly in holes.


----------



## goldstar31

[QUOTE="Noel G*************at is the ONLY blade that Ive broken in more than 60 years..but Im NO hero but I was just tort how to use one correctly

..Guys STOP over thinking things and just DO IT>
[/QUOTE]

The spell check is- well, amusing!  I hope that it  got 'Taught' wrong as the 'Law of Tort' got me quite excited- and I got it 'wrong'. There's pun there

Right?  Oh, never mind

Norman


----------



## fcheslop




----------



## Richard Hed

fcheslop said:


> View attachment 120111


These guys are all idiots--not one of them has safety glasses!


----------



## Steamchick

Love the cartoon - sums it all up very well. - Especially the use of his Tea as lubricant? - if I have interpreted the cartoon correctly? - Wonder if Black coffee will work? - No Milk, so no grease, and coffee is acidic so has higher friction I believe? - something "molecular" someone told me - but maybe I am wrong? I'll drink it instead...
Using my back toolpost yesterday with a home ground high-speed steel insert I cut half way into 1"mild steel without any problem at 300rpm - moving up to 450rpm at about 3/4" dia., but when I changed to the Cobalt steel (narrower) blade on the front toolpost to get deeper the other tool could reach (at 600rpm), it dug-in and stalled the lathe twice.... and has blown something internal in the electrics of the Variable speed drive! "Ham-fisted me" rushing the last 3/8" when the steel was moving so much slower? I do notice that sometimes my muscle control isn't as perfect as when I was younger.... maybe when my blood sugar drops a bit? - it was just before meal time... so maybe it is the "people factor" that causes most problems? Also the cobalt steel tool was "singing" - not heard that before? - Not affected by speed, feed, lube or dry, so I think it was its natural resonance at being stuck-out further than my usual setting, so I could get 1/2" deep into the work-piece.  I guess that at my usual "extension" of that tool it was singing above the natural range of my old and knackered ears, but on this setting the frequency was low enough so I could hear it? It's unknown, hard, Bright steel bar I was given... maybe more than just Mild Steel? Certainly much harder than cast iron, or brass. or my "cheap bought" steel bar. The hack-saw completed the job, but now I have to investigate the VSD electronics to see what has gone O/C? Ho hum!
K


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## Steamchick

Richard, When do you wear safety glasses using a hacksaw?
K


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## goldstar31

Steamchick said:


> Richard, When do you wear safety glasses using a hacksaw?
> K



Do people actually use hacksaws in this enlightened age? 
I always felt that they were a useful source of parting blades


----------



## Richard Hed

Steamchick said:


> Richard, When do you wear safety glasses using a hacksaw?
> K


He's still got chips made and is cutting on a lathe so obviiously he is STILL an idiot.  I lookt for a tea cup but could not see it.  Is that the oiler?


----------



## Steamchick

Hello Goldstar31: 
I re-use hacksaw blades for many things: Without teeth for Spacing tools to the correct centre height, or against a round bar in the chuck to check the centre height of tools. As slim tools for grooves - and parting - when re-ground. As blades for scrapers and crude knives for cleaning surfaces. As long slim scoops for applying flux when silver soldering. For stirring paint: (heat one cherry red, apply a twist for part of the length - like making a twisted poker in school - Did you go to school?) - then holding a flat portion between jaws of the battery drill chuck for stirring your paint. As a "twanger" - like you did at school with a 12" wooden ruler - hold one end on the bench/desk and twang the other bit that sticks out away from the surface. You remember that one, surely? - Or many other uses!
"Now-a-days": Many use angle grinders with cutting discs instead of hacksaws - and similarly in place of filing.... But some of us old f#%ts still use tools we learned to use some decades ago.... Like slide rules, calculators, Drawing boards, pencils, fountain pens, sewing needles and sewing machines (well, my wife uses sewing tools). And in the garden there is still a place for trowels, forks and spades. I paint the house using paint brushes and rollers. I fix woodwork using saws, chisels and affix screws with screwdrivers and use hammers on nails. It is what I call "occupation". I also get a mental reward from completing a job well, and maybe some financial reward from having money left in the bank to pay for Holidays.... Finally, I have companionship by discussing this with all of you interesting people on the HMM Thread-site. - And the mental challenge of beating spell-checker!
What satisfaction! 3 necessities to happiness: Occupation, Reward and Companionship! = I have a happy retirement!
May you enjoy yours as much!

Oh, forgot why I was coming back to the Thread... I found the fuse hidden in the back of the control box. F 10A, 250V glass tube empty of the fuse wire! (That's the "thread" of today's lesson). More care to be taken next time I am parting-off from the front!
K


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## Steamchick

Hi Richard: Correct! - I couldn't see it was an oiler without my spectacles.... Thought it was his Tea-cup...
K


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## Peter Murphy

Richard Hed said:


> These guys are all idiots--not one of them has safety glasses!


And 3 of them have long loose sleeves!!


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## ajoeiam

fcheslop said:


> View attachment 120111



Who's the artist?
(Don't see a signature - - - sorry!)


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## Steamchick

Here's a view of a hacksaw blade in later life.... showing my parting tool just a tad below centre. Probably why it digs-in! But a shim cured that.
Hope you can learn from my mistakes? (And teach me about other mistakes I have yet to make!).
K


----------



## Steamchick

Sorry, pressed the "Post" button accidentally:
Here's the pictures. You can identify the hacksaw blade used between the tool and the surface of round bar and compared to the square. I deliberately used a photo of a WRONG setting as it is easier to appreciate how this set-up makes the actual tool-set position very visible. a few thou" extra shim made the tool level with the centre of the workpiece, when the hacksaw blade became in-line with the edge of the square. - Try it and learn.
Also, viewing teeth of the hacksaw blade against the flat surface of the chuck face (or other square surface) you can clearly see that the parting tool blade is aligned correctly = perpendicular to the axis of the lathe. The reflection of teeth on a smooth surface easily identifies the slightest "out-of-alignment" of the tool. - I deliberately broke a new blade as using "worn teeth" or "bent blade" doesn't give any accuracy in this application. Of course, you can use any precision parallel - e.g. a HSS tool or rod, or gauge parallel, but seeing the straight edge against the surface of the chuck is not as easy as seeing the points of the teeth of the hacksaw blade meeting their reflections - at least to my eyes. (I was about 14 with excellent eyesight being taught by a 60 year old toolmaker to do this). Try it and see?
K







Hope it is useful?
K


----------



## cds4byu

ajoeiam said:


> Who's the artist?
> (Don't see a signature - - - sorry!)


I believe it says B. Terry Aspin  under the title.  According to Google, Terry is the author of three books on home shop metalwork.  I've not read any of them.


----------



## Shopgeezer

Great cartoon. I have to weigh in on the side of carbide. Having started in the hobby late in life without the benefit of 40 years experience, trying to free hand grind a complicated lathe tool is beyond me. I took some courses at the local community college and the instructor gave up on my elbow flapping attempts to grind a knife tool. I have a nice collection of pre-shaped carbide tools and enjoy using them. 

However I did discover the diamond tool holder and find it very easy to grind and sharpen tools for this system. It cuts beautifully. A round HSS tool and a light cut creates a mirror finish on brass. They offer a method to grind a threading tool for this system but that goes beyond my ability to understand complex shapes, let alone create them. I use carbide for everything else.


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## goldstar31

Oh Joy unbounded- a bit Gilbertian for some. But I made a Quorn tool and cutter grinder somewhere in my 90 years.
I am assured- oh yes, by the Professor himself that I can sharpen blunt hacksaw blades.


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## fcheslop

The cartoon was tongue in cheek
Probably when it was drawn elf n safety didna exist or was known a common sense  and apprentices would be firmly beaten around the head for misdemeanours as it was the part of the anatomy least likely to be damaged
Most at that time who owned or aspired to owning a lathe would have been middle engineering management and would have had some basic training when at school .Sadly in the UK this is no longer the case .
Just the ramblings of a locked in grumpy old git who converted to a rear parting post 35 years ago and have never gone back .
I find on small model makers lathes including Myfords parting can be a pain and yet on a proper tool room machine of similar size to the Myford the same tool will cut as if going through butter Hmmm just wonder if the better larger slides and machines mass oh and better headstock help just that bit
I dont own any carbide tools so have no idea if they are truly better or  just that they are ground correctly in the first place
Coffee is for drinking and makes a poor paint brush cleaner when you dip the brush into the cup instead of the tin although in some cases improves the taste of the coffee. For my sins I worked in the coffee industry for 20 years even teaching Italians how to make an espresso
cheers


----------



## BaronJ

goldstar31 said:


> Do people actually use hacksaws in this enlightened age?
> I always felt that they were a useful source of parting blades



The short answer to that one is yes !  Anything that I can't put in the 6X4 bandsaw, such as shortening screws or making slotted screw heads.  

However I would agree about using old and broken ones, power hacksaw blades are useful as parting blades and knives.  I've even got a forked screwdriver made from a broken one.


----------



## RM-MN

fcheslop said:


> I dont own any carbide tools so have no idea if they are truly better or just that they are ground correctly in the first place



Inserted carbides are not superior to a properly sharpened HSS tool but they come from the supplier sharp and of the correct shape.  They often have chip breakers built in that are difficult to match with grinding HSS tools.  When damaged it only takes a minute to turn the insert to a new face or replace it and that new one will be exactly the same as the original, plus the OK ones are very cheap.  Really good ones cost more but then most superior tools do.

Where the carbide insert tools really come into their own is when you have sufficient power and need to take big cuts fast.  Their ability to retain the sharp edge under these conditions makes them the obvious choice in many industries.. until you get to the point where even carbide isn't enough and ceramic takes over or in non-ferrous metals where you can use diamond.


----------



## goldstar31

BaronJ said:


> The short answer to that one is yes !  Anything that I can't put in the 6X4 bandsaw, such as shortening screws or making slotted screw heads.
> 
> However I would agree about using old and broken ones, power hacksaw blades are useful as parting blades and knives.  I've even got a forked screwdriver made from a broken one.


Yes John, I agree but at my experiences- from the time that I was just old enough to watch my father working, I found the so called advice unnecessarily   disparaging.


----------



## fcheslop

RM-MN, thanks for the reply. I have to admit I do have a carbide bit of tooling its laid in a dark corner with the spiders for soo long. Its a graver and never did get on with it 
Most of my machining now is for pleasure and Im happy to live life in the slow lane .Most of my work is done with gravers or form tools made from old files or gauge plate yep another penny pinching perisher or my ancestry kicking in.
Most of the very little paying work tends to be of a horological nature or automata so that leaves me plenty of time to play with the odd model boat or Stirling engine
Concerning parting I guess with a bit of patience and reading on the matter most will find a way that works for them or at least within the capabilities of the machine
Keep well
cheers
frazer


----------



## retailer

This thread has been running for quite while and doesn't seem to want to die so I may as well put in my 2c worth.
My first lathe was an Australian made copy of a Britania made around the early 1900's, while it could do good work once one was aware of the short-comings  it was flexy and not very rigid, my first attempt at parting was a disaster so I tried to avoid that operation as much as possible, I attended a tool sale and picked up a tangential parting tool, my guardian angel had guided me in the right direction that day, with care I was now able to part off mild steel - I still had to be careful and use plenty of cutting oil, keep the feed constant etc but at least I no longer had to hack through a 35mm diam mild steel bar with a hand saw and then face off the jagged cut.


----------



## goldstar31

In Home Model Engineering Clearing house of which I have long been a subscriber, there is a series of examples of parting tool construction in'What I have done today'  Runs from the 20th October

Clears throat- I have made both examples as well


----------



## IanN

Hi,

Parting is a very brutal process - if you use a standard size parting tool (rather than a thin "hacksaw blade" tool) you are probably cutting a groove about 1/8th inch wide (sorry to revert to aliquot parts but I'm of an age where the inch is my natural unit).  Something to remember is the available power on a hobby size lathe

I was taught the rule of thumb that on a small machine you can reasonably remove about 1.5 cubic inches of steel per HP per minute. (This is power at the tool cutting edge, not at the motor)

So if you have a 750W / 1HP motor and ignore inefficiencies, effect of blunt tool, poor cutting fluid supply, etc, etc, and you part a 1/8 inch width with a depth of cut of 10 thou (1/100 inch), then in one minute you can expect to cut off a strip of swarf which is 1/100 thick, 1/8 wide and 1200 inches long.

Given a work piece diameter of one inch and a value of pi = 3 you have a circumference of 3 inches, so 1200 inches of swarf is cut in 400 revolutions i.e. a cutting speed of 400 RPM max.  Now factor in the inefficiencies and it is reasonable to halve this speed estimate.  On my 100 year old lathe I have a choice of three direct speeds via the layshaft pulleys and three backgear speeds so I can get full motor power at chuck speeds as low as 40 RPM, but "cheap" VFDs will not be able to deliver full shaft power at low speeds (whatever the makers may claim.....)

Bearing in mind the above, and the fact that early chattering is corrected by increasing the depth of cut, it is easy to push a small machine outside of its comfort zone when parting.  If you do this, then you can expect to have a few interesting issues from time to time.

All the best,
Ian


----------



## djh

_ I am sure i have commented on this problem on this site before parting off should never be a problem even with wide parting tools but you must  support it with tail stock no need to centre it first just force a running centre or a solid centre or even a flat bar held in the tailstock just keep it supported tight by maintaining pressure on the part wihlen parting release tailstock pressure when almost trough
using this method i have many times cut multiple 2 inch dia billets 6 inchs plus from chuck even when the machine has loose bearings as many of the old machines i had to use had.
David._


----------



## Steamchick

Exactly my perspective, as I have stalled my 750 watt motor - at lower speeds of the VFD. - very easily. I understand the torque is limited by the current - and with 10A fuses I found last week that was the limit! I was too slow hitting the STOP when it stalled, parting at about 3/8" dia and when my hand "twitched" and gave too much cut. Something I couldn't do on my Granddad's 1930s 3in. lathe , or on my Myford ML3, on the back gearing - both of which were smaller lathes than my current Chinese job.
To put it in perspective: 750W is drawing 3A at a spindle speed of 1250rpm... I guess to get 750 W at a spindle speed  of 375rpm it will try and draw 10A - but the electronics don't work that way. (Squarish waves chopped in length to give the RMS voltage for the speed required). so I figure anything below 400rpm my lathe is drawing the "limiting current" that the VFD can deliver, but power is already down, torque is dropping off at at 100rpm spindle speed I have the equivalent of less than a 75W motor. I can't even tap a 1/4" whit in mild steel... just about manage 1/4" x 26 in Brass!
But a geared lathe (belt drive or helical) should deliver full power and torque from the motor multiplied by the gear ratio at lower speeds! = A Fantastic amount of torque that will snap taps and tools when something goes wrong. 
When I have a bigger workshop I'll get a geared lathe, as VFD is just "the wrong method" of powering at lower speeds (Below 500rpm in my experience) for cutting metal.
K


----------



## Noel Gordon

Hi Ian, interesting thoughts, HSS if ground properly is very sharp and requires little HP to make it work. Carbide is never sharp and removes material by shear friction so carbide is great to use when you have unlimited HP. After 60 years I still prefer to use HSS especially if you unstable job that requires careful machining.


----------



## Ken I

*An Unexpected Improvement In Part-Off Performance.*

In another thread I am describing changing my single phase lathe motor (by rewinding it to three phase) and running of a VFD (variable frequency drive).

Single Phase To Three Phase Rewind - Lathe Uprate

An unanticipated (and much appreciated) outcome was an improvement if part-off performance - here's why (I think) :-

A normal squirrel cage motor responds to increased load by increasing its “slip” – it runs slower – this increases the voltage induced in the squirrel cage bars thus increasing the current in the bars and the reaction torque to the rotating field – the downside is the increased slip also increases the impedance of the squirrel cage which diminishes the current and at some “tipping point” stall occurs suddenly.

Typically slip is 5% - this is no small issue – take for instance when you are parting off – as you apply load (feed) the spindle rpm’s will slow down slightly – which in turn actually increases the force being applied to the part-off blade – so the process is made inherently unstable. Sure the inertia of the system comes to your aid – but “slip” is not your friend.

With the VFD the speed is maintained by reacting to the current draw and Hall-Effect feedback caused by the out of sync squirrel cage current reaction.

The VFD actually increases the output frequency (but not the reference frequency display) to maintain speed.

The V1000 VFD (that I used) has two features :- “slip correction” and “torque correction”, the purpose of these is to maintain the rpm’s of the motor at the “reference frequency” rpm.

Example if I dial in 50Hz. The unloaded 4-Pole motor will turn at 1500rpm but as the load increases it will slow down to 1425 rpm – what the inverter does is increase the output frequency to ±52.6Hz to keep the motor turning at the indicated 50Hz/1500rpm.

Now I hadn’t given this much thought but I found that parting off was much improved by both the increase in deliverable power, torque "smoothness" and speed stability provided by the VFD.

I'm not entirely sure how much I can ascribe to just the increased power but I suspect the rpm stability is significant.

Regards, Ken


----------



## Steamchick

Brilliant! (I think?). - But not for those of us who are not about to convert our 750W single phase motors to 2HP 3-phase... with a new VFD. - I'd sooner buy a geared lathe - to gain the torque at low speed - and with a larger stiffer bed. (Lathe bed, not the thing I sleep on for my aching back!). - But thanks Ken, I think this screws my hypothesis that the single phase small motor lathe is no good because the VFD limits the torque as speed drops.... so the job can easily stall?
No matter, I rarely have any problems parting-off (I never say never). "Slowly and carefully" has worked for 50 years for me. - And applies to my 90W motor Unimat SL just as well. (But a small hacksaw is much quicker!). But I'm glad to hear of your success and a worthwhile theory! Bravo!
K2


----------



## Ken I

Ken 2, I used to have (in fact I still do) a much smaller D.C. motored lathe - which I persevered with (But a hacksaw is much quicker!) my new geared lathe was something of a disappointment in this respect - now much better.

Regards, Ken I


----------



## OrangeAlpine

I found the problem!

Being almost 80 and loosing strength, I had decided to switch to smaller, easier to mount chucks.  So I machined #4 Morse taper onto three slugs of mystery metal and a drawbar to hold them into the lathe spindle.  The 5" chucks are mount (of course) on these Morse taper adapters.  I decided that perhaps the #4 tapers were not making as good a contact in the lathe spindle as I thought.  I was right.  A little Prussian Blue and a fine file file put brought them up to where they should have been.  

I have recently parted some 1" stainless steel.  I have no idea the type.  It was purchased simple as 1" steel.  It machines fairly good, but seems to require a rather high pressure and continuous feed.  Anyway, the parting was successful with nary a chatter or dig in.

BTW, I love my new "quick change" chucks!  

Bill


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## jackary

Here is my submission to the discussion, its all about rigidity at the mounting including the topslide etc 
Alan


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## Steamchick

jackary said:


> Here is my submission to the discussion, its all about rigidity at the mounting including the topslide etc
> Alan



Better than my back-toolpost! Must modify that now, to increase stiffness. I like your mount and blade though, that may be the best ever!
You are right about maximising stiffness. The thrust from workpiece to lathe bed simply compresses the cross slide and saddle slides - no chatter possible there. Can't improve the stiffness beyond the bed to head stiffness made in the factory though...
Or buy a better lathe.
K2
K


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## Steamchick

My back tool-post is a post with tool holder mounted on it, tool " upside-down", but seeing you have solid metal all the way from cutting edge to surface of slide you have eliminated the bending I have in my toolpost. This tiny bending is probably the "prime exciter" when I do get any chatter, so to modify the toolpost so  I have solid metal from cutting edge to cross-slide surface should eliminate that. I.E. eliminate the overhang of my tool.
Thanks!
K2


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## jackary

In order to clarify the operation of a vertical parting tool here is my rather primitive description of how I think it works.

Imagine that you are the parting tool holder whereby your two hands are held straight out from you body. You hands are gripped together and your fists are the cutting edge. You have a friend who represents the metal being cut and he (If you are a front parting tool) pushes down on your hands while you do you best to resist him pushing down. You can see that he can quite easily push your arms down. If you want to now become a rear parting tool you can turn round 180 degrees and your friend would now push your hands upwards still he can easily overcome your resistance to him pushing up. So in order to stiffen you up, say you are frozen solid or have rigor mortise and are wearing a large pair of lead diving boots to anchor you down. When your friend (or should I now say de-parting undertaker) pushes down on you hands he will not be able to move your arms down because they are rigidly fixed to your body and he have to apply more force until you tip forward on you toes. Note that as you tip forward you rotate about your toes moving your cutting tool hands deeper into the metal being cut.  If you are now rotated 180 degrees to become a rear parting tool your friend (some friend) now has to apply more upward force until you tip backwards on your heels. Also note that your cutting tool hands now move away from the metal being cut as you rotate backwards on your heels. Now you have to play the part of a vertical parting tool as I am proposing, so you now can be thawed out or de- rigor mortised. So lay flat on your back and push one arm vertically upwards and clench your fist to form the cutting tool. Your friend now has to apply considerably more force to overcome your vertical arm. Your arm will be in direct compression and until your elbow or wrist give way you will have much less a problem resisting his downward cutting force. It will also not matter if you are a front or rear vertical parting tool as long as the rotating force is pushing down on your hands. You can now get up and go back to your work or whatever you were doing. I apologise for being so flippant but I hope it does explain the reasoning.

Regards

Alan


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## Steamchick

Thanks Alan, very clear. My thoughts are to convert my rear toolpost (tool up-side down and "normal RH rotation") to make it stiffer with a rib supporting the tool right down the the surface of the cross-slide, and with "rotation reversed, LH" as you demonstrate. A bit like "sticking your hands out to the cutting edge and having a plank on-end beneath to take the thrust".
I am sure your sharp cutting edge, tool cutting angle, speed and feed rate are all "text-book" as well.
Thanks for excellent advice.
K2


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## goldstar31

Ken the GHT tool holder is structured into protruding exactly 1" and there will cut any  bar with a maximum of 2"diameter.
You make it, and all that you need to do in a normal lifetime is 'lick' and tap the refurbished blade to dead centre again as it was before the grinding. the front cutting edge.

None of this 'standing up in a hammock', GHT does it-- end of it- simple. He did the thinking-- and got it right. Far too much blethering from the lesser mortals . My opinion of a LOT of years

Norman


----------



## Steamchick

Thanks Norman. Generally, I have no problems with my set-up and tooling, but reading this thread I have recognised some clever and better ways of killing the pig. And , of course it is nice to make things and experiment to see "why" things are done different ways. I have such a small (Chinese) lathe it poses some odd challenges, as it definitely will twist or stall at max cut rates! So "slowly and carefully works best". Been making a couple of jets this last couple of days - in gaps from other jobs. Drilling 0.25mm (0.01") holes in brass focuses the mind. Production sequence solves most problems! 0.3mm dia is much easier as drills are just stiffer and stronger. I figure my beard hair can break a 0.25mm drill. It's tougher than the swarf!
Be safe, be happy, 
K2


----------



## goldstar31

Steamchick said:


> Thanks Norman. Generally, I have no problems with my set-up and tooling, but reading this thread I have recognised some clever and better ways of killing the pig. And , of course it is nice to make things and experiment to see "why" things are done different ways. I have such a small (Chinese) lathe it poses some odd challenges, as it definitely will twist or stall at max cut rates! So "slowly and carefully works best". Been making a couple of jets this last couple of days - in gaps from other jobs. Drilling 0.25mm (0.01") holes in brass focuses the mind. Production sequence solves most problems! 0.3mm dia is much easier as drills are just stiffer and stronger. I figure my beard hair can break a 0.25mm drill. It's tougher than the swarf!
> Be safe, be happy,
> K2


thanks for comments but I thought that you were using a ML3- so silly me. So  from my sieg c4, a bit bigger than yours? I  made sub plates to accept my Myford accessories( and vice versa)
So today my Potts vertical slide with a 9 hole dividing head and a Myford 2MT spindle and nose has arrived. 
next job is making Tee nuts( if the weather warms up but my central heating has broken down and  I;m wearing down jacket, gilet and  whatever.

So keep in touch

Cheers

N


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## Steamchick

Hi Norman. The little beast is a Chesters DB8VS. 8"Swing over bed, but not robust for that size of job, except with light cuts. You really need a gear lathe - not a 1 HP / 750 W variable speed that equates to about 7W when at lowest speed ~100 rpm. But good up to and inch or 2. Better than the ML3 it replaced, except for the back-gear on the Myford  that was great for larger diameters like flywheels. But I often found that bed twisting when I tried a cut that was too heavy.
The DB8 fills my limited space.
Cheers,
K2


----------



## goldstar31

Hi Ken

Thank you for your detailed explanatio,

best Wishes

Norman


----------



## Richard Hed

Steamchick said:


> Thanks Norman. Generally, I have no problems with my set-up and tooling, but reading this thread I have recognised some clever and better ways of killing the pig. And , of course it is nice to make things and experiment to see "why" things are done different ways. I have such a small (Chinese) lathe it poses some odd challenges, as it definitely will twist or stall at max cut rates! So "slowly and carefully works best". Been making a couple of jets this last couple of days - in gaps from other jobs. Drilling 0.25mm (0.01") holes in brass focuses the mind. Production sequence solves most problems! 0.3mm dia is much easier as drills are just stiffer and stronger. I figure my beard hair can break a 0.25mm drill. It's tougher than the swarf!
> Be safe, be happy,
> K2


How deep do you have to drill those tiny holes?


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## Steamchick

I drill 1mm as deep as needed to get the gas to the jet: then the jet itself is 1~3mm through the final wall of brass. A good set-up will drill 5 holes before I lose the drill. (They are not strong enough to cope with the break-through - and the lathe gives very little back-pressure "feel" at that size of hole). A bad set-up won't drill. The jets are typical 7mm long, hex brass either 3/16" (3/16" x 40 thread) or 1/4" AF. (for 1BA) - With thread to suit the jet holder. (1BA is used in UK as a standard by some suppliers).
I buy no 5 (0.20mm) and no 3 (0.15mm) jets - cheaper than drills for me! But I mostly use no 8 (0.20mm) or 12 (0.30mm) jets - or larger number drill sizes - for my ceramic burners.
It's just a bit of fun (challenge?) - to keep me from following the misses around the house!
K2


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## goldstar31

Steamchick said:


> It's just a bit of fun (challenge?) -
> K2


I'm sure that I have repeated this
A old Myford ML2 in good hands should be quite capable of drilling a perfectly parallel 1/8th hole up to almost 13 inches in African n Blackwood or similar  exotic hardwoods. 
I recall overhauling a Myford which had been in almost daily use doing such things. 
A chanter of a set of Northumbrian Small pipes is a bit shorter than that but 'that's the name of the game. I made a set out of Kingswood and partridge wood.

Years ago, a Scot asked in ? Model mEngineers Workshop how to sharpen a Napoleonic bayonet and 
I reokied back asking him how he was getting on with his set of Highland Pipes.  Simply deduction.

Different World!


----------



## goldstar31

Thinking of drilling prompts me to an account, perhaps apocryphal but indicated what the North East of England could do. After all but we invented the steam locomotives, we invented the steam turbine, arguably invented 'electricity' and got a reputation for making money in the American Civil War and built the Sydney Harbour Bridge and --- made the Imperial Japanese Navy.  As our sort of last parting shots we took  a battle ship  - unfinished, guns untried and completed the destruction of the German Navy by sending out archaic torpedo bombers made out of string ad chewing gum after we had put the Italian Navy into harbour- for the whole wa. The Japanese actually watched us doing it to the Italian Navy-- and went and tried it out in pearl Harbour. 
So years earlier, we drilled a domestic sewing pin - lengthways and sent it to the Japanese- as a joke.
They didn't see the joke and returned it after drilling another hole etc until one wit on a Tyneside toolroom engraved the Lord's on the head of the pin. How true the story is , we don't know but the Germans never ventured its remaining battle ship and left the Tall Boy bombs made on the Tyne o turn it into a tin grave yard.  Apart from the pin, the rest is ACTUALLY true!
As a toddler of 7 or so, I watched HMS Manchester who took part in the Sinking of Bismarck was pooping off her guns that were made on the Tyne in 1914-18. Of course, my local pride will never disclose that our ancient torpedo bombers saw what they thought was the german battleship and dropped their torpedos on the surprised HMS Manchester.  As nothing is perfect, the torpedos exploded harmlessly on hitting the water


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## Steamchick

Love it! Norman, you have a book in you, just all the tales, anecdotes, history and experience should be recorded - perhaps in a better place than this site. I would buy the book!
The tale I heard, was that the Americans made a glass tube smaller than a hair.... and the British returned it with another smaller glass tube inside it.
With the passing of a famous test pilot - Chuck Yeager - I am reminded that we designed his plane, then the design and calculations were passed to the Americans after the war as a political gesture, for some obscure reason. (Perhaps for donating "a million" lads to the second world war who never went home? But that can never be compensated.)
Sorry, I digressed.
Keep on with the anecdotes. Most interesting.
K2


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## goldstar31

Ken
         Thank you but I have only written ONE story with me in it.  I was almost forced to have done it !

What I have written is about the courage, the dedication - and usually the sacrifice of people- that were never really given the recognition that they  IMHO rightly deserved. 
We, that is my beloved Royal Air Force Squadron have a motto in Latin but reads "First in the Indian Skies' but  managed to write 'Almost first in the Antarctic Skies'. It was as far as possible told the difficulties and deaths in some cases of people that  that I knew- and greatly respected. 
If you believe in Fate or whatever they call it, I was simply county the firm's money and my phone rang.  There was a place for me on not an Antarctic Expedition but the Arctic- and I was to meet the man who tried to be the first to fly to- not the South Pole but the North Pole. The difficulty is trying to condense a huge story so that the reader will perhaps enjoy it. 
My little grand daughter was doing a school thing about the War and  I spent quite a time explaining as best as I could to a child. At the end she wrote much as follows:-

GrandDad was in the War as a boy, there was bomb that didn't go off and then it killed a cow.

I have a little competitor and she's clearly better than me.
Cheers

Norman


----------



## Richard Hed

Steamchick said:


> Love it! Norman, you have a book in you, just all the tales, anecdotes, history and experience should be recorded - perhaps in a better place than this site. I would buy the book!
> The tale I heard, was that the Americans made a glass tube smaller than a hair.... and the British returned it with another smaller glass tube inside it.
> With the passing of a famous test pilot - Chuck Yeager - I am reminded that we designed his plane, then the design and calculations were passed to the Americans after the war as a political gesture, for some obscure reason. (Perhaps for donating "a million" lads to the second world war who never went home? But that can never be compensated.)
> Sorry, I digressed.
> Keep on with the anecdotes. Most interesting.
> K2


Maybe because the US and GB were allies but GB was totally broke after the wart?  After all, the US emerged, at that time, as the great power.


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## goldstar31

Last Night, I was drinking with someone who was on a Liberty ship built in --- ???24 hours in Henry Kaiser's Yards.

We still can't afford to pay for them
I was injured in service as a Non Commissioned Officer( possibly the youngest then) and my pay was less than 2 Dollars a day. I had my ears blown in with sweating relegated ammunition left over from the war. It took 70 years to get my hearing aids. The lucky ones got  Ear Defenders- which were-------
made out of  woooooooooooood! Heigh Ho!


----------



## fcheslop

When making small gas jets. I drill 0.3mm then swage down to the size needed. It saves snapping those drill bits
It is just a simple jig , punch and guide to keep the hole middle for diddle. The wire is easily found
I also tend to make batches of 10 and need to make some more shortly 
cheers


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## Steamchick

"A better man than I, Gunga Din".
I would be interested to see your guide and punch? - Just curious, mind you, as I rarely make burners so small to need less than 0.25mm jets.
Thanks,
KL2


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## Steamchick

Richard Hed said:


> Maybe because the US and GB were allies but GB was totally broke after the war?  After all, the US emerged, at that time, as the great power.


I understood it took the UK until the 1960s to pay USA for the war. - About 20 years? But I don't think Germany or Japan ever had such a debt.? They went from totally broke to being supported by the US during their re-build -  or so I was told? 
Not sure I understand what really went on, but I do remember streets with no cars, no refrigerators, no TVs, no kids with bicycles (some with hand-me-down shoes! - we all had hand-me-down clothes), no central heating (just a single small coal fire.. and frost on the bedroom window every winter morning), Growing potatoes and cabbages - one sausage or one lamb cutlet was the meat on your plate - and being happy and laughing! Today's kids just can't imagine what we had... 
By comparison, the current Pandemic is supposed to take 3 years for the UK to pay back the loans from the IMF - on a similar basis. So tighten your belts!
And we'll still have our central heating, etc. , internet toys, TVs, Netflix, trainers and designer perfumes, 3 car families, (parked on the street as the garage is full of bicycles we don't ride and guitars we don't play!), and mobile devices worth more than a month's wages! Half the shopping will be delivered to the door - food already coked and ready to serve - and we'll enjoy 3 holidays and a few weekends abroad...
And laugh at how we "suffered" during the pandemic.
Well, some of us will have finished some models that were intended to never be finished...
"Nostalgia ain't what it used to be!" - to quote my Grandfather.
K2


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## Steamchick

If anyone wonders what that has to do with Parting Tool Chatter - sorry, it is just "chatter"! - vis. *chatter* verb _ (TALK/NOISE) to talk for a long time about things that are not important: 
K2_


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## Steamchick

The reference to Gunga Din:
"*Gunga Din*", lines 82-84 View the full poem on Wikisource. The poem is a rhyming narrative from the point of view of a British soldier in India.Its titular character is an Indian water-carrier (a bhishti) who, after the narrator is wounded in battle, saves his life, only to be shot and killed. 
I heard some years ago, that I am distantly related (by surname) to the only civilian who was awarded the Victoria Cross. 
George Chicken VC.
*George* Bell *Chicken* *VC* (2 March 1833 – May 1860) was a British sailor and a recipient of the Victoria Cross, the highest award for gallantry in the face of the enemy that can be awarded to British and Commonwealth forces. He was cited as he was with a party including British soldiers, ambushed by revolting Indians, and after the forces were mostly overwhelmed drove off the Indians as the last man able to fight. - or some such. His ship foundered on his return to England, but the officer commanding the troops had written so well of him in Dispatches - saving all the remaining lives - that he was awarded the VC posthumously, before they decided it should be a purely military award.
Just a bit of "Gunga Din" spirit?
K2


----------



## ajoeiam

Steamchick said:


> I understood it took the UK until the 1960s to pay USA for the war. - About 20 years? But I don't think Germany or Japan ever had such a debt.? They went from totally broke to being supported by the US during their re-build -  or so I was told?
> -  snip


You may want to check that assertion that Germany didn't pay any reparations. (Dunno about Japan though - - - sorry.) 

The reason it looks, from today's perspective, that they didn't have to pay comes from the fact that the industry in both Germany and Japan were so destroyed by the end of the war that the aftermath meant they had to build new. That new was far more efficient and so made them a lot of money. The US - - - not having 'enjoyed' catastrophic destruction of their industry - - - continued to use the older technology until it was really clear that they were getting beat up. That realization took a long time to sink in it would seem.


----------



## Steamchick

You are correct. Germany did pay reparations, but things like a DKW 2-stroke engine design for what became the BSA Bantam (which was then produced on the clapped-out tools left from making WW2 stuff) and lots of other "technical" reparations with a book value determined by non-technical people - using ideas of value from pre-WW2 - were not the same as the Gold transferred from the UK treasury to Fort Knox.... Still, despite that, the UK trades "above its weight" on global markets, as perhaps the 1980s showed we can still do. On the subject of tooling - as I experienced, as well as my Seniors taught me, the Americans sold/shipped their clapped-out 1920s and 1930s tooling across the Atlantic, and used new 1940s tooling for their War Effort. I was taught in a machine shop in the 1960s using that same worn-out 1920s and 1930s American tooling - lathes with 3~6 thou wear in the bed so on a cut of more than a couple of inches I had to compensate according to a table written on a piece of paper, and chalk marks on the lathe! Otherwise a 4 foot shaft would end up like a cucumber!
Nuff said, it is History, and History buries unpalatable truth. The reality of what we have inherited cannot be changed, just re-written.
I'll crawl back into my bolt-hole.
K2


----------



## goldstar31

ajoeiam said:


> You may want to check that assertion that Germany didn't pay any reparations. (Dunno about Japan though - - - sorry.)



of course this must be assumption- and the famous, 'I knew a man, who knew a man*******'
You see  I walked in as then the newest "Goldstar in RAF  Transport Command, 46 Group (Rear) at a resurrected RAF 31( The Goldstars) Squadron who were part o with 38 Group which was running Operation Plain Fare. Quite a mouthful-- and one which probably has never ben mentioned- by the man that knew a man that knew a man ********.
You see, unless you are at least 94, you have no first class evidence of what went on. The rest of these  ones who have ffirst hand experience are either gaga or-- sadly DEAD.  As far as my little place there are only two of us.

 Next morning- I hd escaped  being re-mustered and - well the rest was history.


----------



## Steamchick

Understand. Heard tales of Planefare - life on the ground in the "delivery zone" - from an Uncle "who was there". They could talk about "non-warfare" activities. My 99 year old Mother is the last of that generation of relatives - and she is Gaga... But the people "who were there" don't usually tell us all. The "war-work" was kept "hush-Hush" and the leave parties were not for their childrens' ears anyway! So we only heard about the nights they were bombed-out - as we played on the bomb-sites as kids we saw some of the reality. All just History now. And Korea, Suez, Russians invading Eastern European countries, Cuba, Vietnam, Falklands, Iraq, Afghanistan... will all become History when we and younger folk have passed... But - having worked with many who were "there" - in various places - none of them talk about the difficult situations - just the amusing ditties that interrupted the phases of terror.

But (like Cressy and  Agincourt) we will remember them... and for those previous incidents, we will remember them through their histories.
And returning from this digression, regarding machining, we will remember "how" through this excellent website, as well as the models that record "Engineering history" in a way that will outlast us all! - Even if "the machines (and people) that made them" have long since been "recycled".

Sorry, that was a bit heavy.... not intended that way.
K2


----------



## goldstar31

And for Ken!

The BSA Bantam was the err favourite transport of little lads who were known as  'telegram boys'. My top erk had had one


----------



## Steamchick

Uncle talked of being on the coal bag brigade after flattening the cities in previous years.... While his plane was being "turned around" sometimes weather, or whatever, delayed the return flight, so he helped the delivery guys on coal trucks. They dumped a bag of coal on odd street corners as it was "perishingly cold" - and the German ladies used to scramble and fight for the few lumps of coal they could gather in their skirts.... They lads figured that only "the rich" got the coal that made it to the depot, and so they let some fall off the back off the wagon to "poorer people" for free. They ladies even swept the coal dust up... Now that is my second-hand tale of Berlin.
K2


----------



## goldstar31

The most coal was brought in by-- flying boat!.  Short Sunderlands were brought in from submarine searches and the Avro Shackleton - which could fly with 3 engines stopped replaced them. I recall Farnborough 1949. Metor 8's with re-heatts and 40 thousand feet in 40 seconds. And then there was Comet One and  Brabazon flew in from Filton. I was on a fiddled leave pass to save money!
I have digressed Yea 'Flying Pocupimes' they used the lakes around Berlin!  Of course it was all good fun. To stop the landings, the Russians pointed their search lights at them.  Of course most of the British lads were demobbed but re-joined at a lower rank and had survived the Bomber Command stuff.  So the experts flew down the beams-- and the Russians got the message.
You see, I missed the 'big Even', missed the Virgin Soldiers in  Malaya, missed Korea and missed flying 'shot gun'in an Ambulance Avro Anson Mark 12 to the Gold Coast. That's a new bit? The natives were revolting..
Shame really but some of it seems still hiddden in the Official Secreta Acts to which I was a signatory.

i was  close as that!


----------



## Richard Hed

Steamchick said:


> I understood it took the UK until the 1960s to pay USA for the war. - About 20 years? But I don't think Germany or Japan ever had such a debt.? They went from totally broke to being supported by the US during their re-build -  or so I was told?
> Not sure I understand what really went on, but I do remember streets with no cars, no refrigerators, no TVs, no kids with bicycles (some with hand-me-down shoes! - we all had hand-me-down clothes), no central heating (just a single small coal fire.. and frost on the bedroom window every winter morning), Growing potatoes and cabbages - one sausage or one lamb cutlet was the meat on your plate - and being happy and laughing! Today's kids just can't imagine what we had...
> By comparison, the current Pandemic is supposed to take 3 years for the UK to pay back the loans from the IMF - on a similar basis. So tighten your belts!
> And we'll still have our central heating, etc. , internet toys, TVs, Netflix, trainers and designer perfumes, 3 car families, (parked on the street as the garage is full of bicycles we don't ride and guitars we don't play!), and mobile devices worth more than a month's wages! Half the shopping will be delivered to the door - food already coked and ready to serve - and we'll enjoy 3 holidays and a few weekends abroad...
> And laugh at how we "suffered" during the pandemic.
> Well, some of us will have finished some models that were intended to never be finished...
> "Nostalgia ain't what it used to be!" - to quote my Grandfather.
> K2


As we are told:  follow the $$$.  The alleged pandemic is destroying small businesses-- does you thimk that is all by accident?  In the US, when the alleged pandemic began, they closed small hardware stores, restaurants and other businesses, however, the large groceries (being necessities) were allowed to stay open.  So wallmart (fall-apart) was allowed to operate as it has a large grocery section.  It also has a hardware section, houseware section, furniture section, toy section, clothing section--ALL WHICH WERE ALLOWED TO CONTINUE!  Seems to me, this was the plan all along, to destroy one's competition.  There most likely is a disease called covid but was it made by humans?  Was (is) it just an election fraud?  Is it realy as dangerous as the child molesting politicians claim? (I doubt it.)  In the 70's there was a "pandemic" that was every bit as dangerous as this one and no one even remembers it.

We are told about the 1918 pandemic that supposedly killt 18M peeps (less than 1% of world population) and we are told about the plagues of Europe and Asia which apparently wiped out huge portions of the population before there was an understanding of any germ theory which came after the US Civil War, with brown rats (or republicans) with their fleas and gthe fleas with their bacteria and the bacteria with their viruses and the viruses with their poisons.  Small pox, apparently a virus, is far more dangerous than this covid.  Polio affected a far larger njumber of people than this covid, so where is the 'pandemic'?  Sorry, but I just don't trust my government, nor any other alleged 'authority' when they have been caught in so many lies.


----------



## fcheslop

Not one to post builds anymore but will do a  wee thread when I make the next batch. Very easy and no faffing snapping those drills and 0.3 is an easily obtained size


----------



## Steamchick

Hi Richard. My daughter works I the medical sector. Yes, Covid exists and fills wards with people. My brother-in-law, in his late 70s, was hospitalised in for 2 weeks with covid, and 6 weeks on is not yet at full health, and there were deaths in the ward from covid. I know other peple who have lost friends and relatives. It is real. 
But if the true figures were known, maybe it would only do be th us all f deaths per winter? However, you can't compare deaths from flu each year in an uncontrolled free society, with Covid deaths in 1 year with quarantine conditions in many places - like Spain, France and the UK.
But you are right. "We, the people" have a responsibility to hold the politicians to task (we tax-payers pay their salaries) and get honest policies and direction for the nation from them. NOT NEWSPAPERS, PRESS AND OTHER BUSINESS LED CORRUPT, SELF INTERESTED, ORANISATIONS. 
Also, as with every disaster, man-made or natural, Joe Public pays in many ways and some businessmen and politicians and "experts" get rich! A natural law exists here I think? Darwin said the fittest survive best... or those at the top survive better than those drowning in the mire at the bottom of the heap!
It does look like there is a "big brother" international conspiracy. I think it is a strategic warfare by the Chinese - where the man-made virus was initially released - to de-stabilise the Western economies, so we become more dependant on imports from China, which can then inflate prices for their goods! Maybe it isn't? Just an unhappy coincidence? But nothing would surprise me...
Back to the workshop to tap a 5/16" BSF thread...
K2


----------



## ajoeiam

goldstar31 said:


> of course this must be assumption- and the famous, 'I knew a man, who knew a man*******'
> snip
> You see, unless you are at least 94, you have no first class evidence of what went on. The rest of these  ones who have ffirst hand experience are either gaga or-- sadly DEAD.  As far as my little place there are only two of us.
> 
> Next morning- I hd escaped  being re-mustered and - well the rest was history.



What is quite clear is that the winners write the history books.

I find it quite fascinating the denigration of oral history displayed. 

Oh well - - - - what do I know anyway - - - - I'm not an American - - -    .


----------



## Richard Hed

Steamchick said:


> Hi Richard. My daughter works I the medical sector. Yes, Covid exists and fills wards with people. My brother-in-law, in his late 70s, was hospitalised in for 2 weeks with covid, and 6 weeks on is not yet at full health, and there were deaths in the ward from covid. I know other peple who have lost friends and relatives. It is real.
> But if the true figures were known, maybe it would only do be th us all f deaths per winter? However, you can't compare deaths from flu each year in an uncontrolled free society, with Covid deaths in 1 year with quarantine conditions in many places - like Spain, France and the UK.
> But you are right. "We, the people" have a responsibility to hold the politicians to task (we tax-payers pay their salaries) and get honest policies and direction for the nation from them. NOT NEWSPAPERS, PRESS AND OTHER BUSINESS LED CORRUPT, SELF INTERESTED, ORANISATIONS.
> Also, as with every disaster, man-made or natural, Joe Public pays in many ways and some businessmen and politicians and "experts" get rich! A natural law exists here I think? Darwin said the fittest survive best... or those at the top survive better than those drowning in the mire at the bottom of the heap!
> It does look like there is a "big brother" international conspiracy. I think it is a strategic warfare by the Chinese - where the man-made virus was initially released - to de-stabilise the Western economies, so we become more dependant on imports from China, which can then inflate prices for their goods! Maybe it isn't? Just an unhappy coincidence? But nothing would surprise me...
> Back to the workshop to tap a 5/16" BSF thread...
> K2


Yes, nothing surprizes, however, it makes me veryangry.


----------



## Shopgeezer

The problem is the wildlife markets in SE Asia. Covid is just one of many coronaviruses that circulate in wildlife populations. The genetics point straight back to bats and possibly cats, maybe pangolins. No epidemiologist believes it is anything else. As a person who loves wildlife and the natural world, it saddens me that we are hammering our fellow creatures into extinction as fast as we can. Wildlife markets and all the snaring and trapping that supplies them should be closed.


----------



## goldstar31

Deleted off topic


----------



## Henry K

As a young graduate engineer in early 1970 I got a job as an Industrial Engineer at Western Electric in Kearny, NJ. WE made all kinds of electrical and electronic equipment during WW2. In the shop area I was involved with we had lots of ladies that worked there during WW2. One of the ladies told me she (about 30 years earlier) worked on a big Top Secret project. She was told she was making power supply parts for a radar detector. She explained it was buried on beaches in England and would warn of German bombers flying in to bomb. I was duly impressed.
  Fast forward, around 2005 a lot of WW2 secret projects were being revealed. I found out that these WE products made in Kearny were not buried in beaches in England. They were complete radar units attached to the bottom of B29 bombers for bombing Japan at night or through clouds and for radar navigation. How was that for keeping a secret. Opposite side of the world and 35,000 feet up as opposed to around the globe and 10 feet under sand.


----------



## goldstar31

For another bit of light reading-- Google The Battle of the Beams.  
I think that Ken2 will also enjoy it.  He was rather near


----------



## Cogsy

goldstar31 said:


> You see, unless you are at least 94, you have no first class evidence of what went on.



There's plenty of documentation that is far more accurate than anecdotal recollections of a single person. Case in point - the F8 Meteor had a maximum climb rate ~ 7000fpm and took 5 minutes to climb to 30,000 feet. Documentation from multiple sources is indeed 'first class evidence' and exists for a very good reason - to record what actually occurred without relying on aging memories, misunderstandings and exaggerations.


----------



## goldstar31

----------------------


----------



## goldstar31

--------------------------------------


----------



## Cogsy

goldstar31 said:


> Hi Cogsy
> No! Sorry but I was ACTUALLY at the Royal Aircraft Show at Farnboro
> ugh in 1949 and vividly recall the BBC correspondent describig the  events. I have a Pelmanistic memory and the. Meteor in question was fitted with  're-heatss'. It was NOT a standard aircraft.
> 
> [SNIP]
> 
> So I must disagree with your information- I was there at Farnborough.  I have no doubt that 'somewhere' there is information  to be concocted to prove my version of events.


A meteor was experimentally fitted with non-standard turbojets in 1948 and went on to set a world climb record in mid-1951 of just over 39,000 feet in just over 3 minutes. Well documented and claimed as an official record by the Brits'. I doubt they'd have been crowing so hard if they'd achieved 40,000ft in 40 seconds way back in '49.


----------



## goldstar31

Typo--
Let him that is without sin, cast the first stone
I'm doing rather well considering my 90+ years


----------



## Cogsy

goldstar31 said:


> Typo--
> Let him that is without sin, cast the first stone
> I'm doing rather well considering my 90+ years


Which bit are you claiming was a typo? The 40 thousand feet was supposed to be 4 thousand maybe, or the 40 seconds was supposed to be 400?? - so why did you ark-up when I mentioned the 7 thousand foot per minute climb rate of the F8? It was at best an exaggeration and at worst an outright lie, and you were caught. Blaming a typo isn't going to fool anyone.


----------



## goldstar31

------------------------------------------------------------------
As far as what was broadcast over the address system was 40,000 feet in 4 minutes and that was on a reheated Meteor. Charles Gardner of the BBC.
I am minded to ask the Corporation of whether there is evidence one way or another to say what was said- not by me but a very respected commentator. What documentary matters you have or can obtain has actually no relevance to what I recollect- on that Sunday at Farnborough 1949.
From what I have read, a Meteor- which or with reheats- for which there will be photos- is or was perfectly capable of producing such a performance.  Please produce what FIRST CLASS  you have of the event THAT day to refute my recollections.
In any even there was no recorded evidence of what ACTUALLY happened. I was and am a an interested party and clearly being maligned other than for reasons which I am, so far not being informed.
You have the opportunity to delete ALL my comments and your own in an effort to endeavour to       return to something approaching harmony in this forum. I now have 3000 postings  most in an effort to the forum and some 970 likes in return for my contributions.\
-------------------------------------------------------------------------------------------

I've just checked RA 435  with reheat was at Farnborough Show in 1949

In addition there is very clear photograph.

Well now? 















Meteor 

Me


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## goldstar31

I've just said 'farewell' to my next door neighbour who has been on life support since 'I went wrong' on the 19th December. 

I can now apologise for the silly mistakes made then. It has left me with. even more damaged sight than could reasonably be expected with old age and increased macular  degeneration. 
So I was sort of lucky after all


----------



## Richard Hed

Cogsy said:


> There's plenty of documentation that is far more accurate than anecdotal recollections of a single person. Case in point - the F8 Meteor had a maximum climb rate ~ 7000fpm and took 5 minutes to climb to 30,000 feet. Documentation from multiple sources is indeed 'first class evidence' and exists for a very good reason - to record what actually occurred without relying on aging memories, misunderstandings and exaggerations.


Wait a minute there,  A lot of "official records", maybe even the majority, have been doctored, reported incorrectly, or not reported at all, or reported as hear-say.  Even official reports are suspect.  Even if reported somewhat correctly,. often an officer or anyone involved might exaggerate their own involvement or take over someone else's involvement (especially if they are ded) to make themselves look better or make someone else look bad.  No end to ways people can manipulate "official reports".


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## almega

Reining this horse back onto the track, so to speak, what about the parting tool chatter?


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## Steamchick

In 16 pages of chatter, I thought the parting tool bit had died a death? Mostly, minimum clearances, sharp tools, as narrow as possible, constant feed rate, and feed slowly and carefully, without any hesitation in the cut, all seems to be good advice. Additional stuff, like different tools, materials, cutting angles, rear mounted upside down tools, etc. are refinements. Which need the first set of criteria to be correct before they can work. Chatter is a resonant frequencyveffect. It is stimulated by a stick-slip action of tool on metal so of course lubricant can change it as well. But only with a system "without slack, with sharp tools, with correct cutting speed and feed" etc.
Cheers.
K2


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## almega

What are the benefits (or disadvantages) of rear, upside down mounting of the cutter for parting off?


----------



## mcostello

I use a front mounted upside down insert parting tool. No where to put a rear tool. The insert tool curls the chip very good, the chip falls down out of harms way. If the tool does jam it is pushed up as I have a BXA quick change tool post. Best of both worlds.


----------



## goldstar31

mcostello said:


> I use a front mounted upside down insert parting tool. No where to put a rear tool. The insert tool curls the chip very good, the chip falls down out of harms way. If the tool does jam it is pushed up as I have a BXA quick change tool post. Best of both worlds.


And Geo H Thomas writing in his Model Engineers Workshop spends 16 pages of drawings and print on  the very subject of a rear mounted tool. This , I have recommended on NUMEROUS occasions--HERE.
Again, Thomas and I share the same problematic lathe that precludes the suggestion of running a lathe with a threaded spindle BACKWARDS.

I Made a GHT  version -many years ago for my Myford-- with great success and and absence of 'unusual' variations. Hemingwaykits( no connection) sells kits for the 7 inch lathe and another for larger machines.

I still have an un-machined casting and new drawings etc


----------



## Richard Hed

mcostello said:


> I use a front mounted upside down insert parting tool. No where to put a rear tool. The insert tool curls the chip very good, the chip falls down out of harms way. If the tool does jam it is pushed up as I have a BXA quick change tool post. Best of both worlds.


I've been paying attention to this thread, and I have a shi*ty little Enco that this upside down on the back side method probably would have helpt me immensely.  However, now I have a new lathe that is rigid, solid, heavy and strong.  I have been parting off from the front, not long cuts, but still cuts the Enco could not have made with comfort, and these are cutting like a hot sword thru . . . . well, I can't thimpfk of a metaphor.  But I haven't had a bit of trouble so far.  If I needs deeper cuts, I use the bandsaw.  Someday, however, I will probably needs to do a deep cut with the lathe and then I might experience nasty chatter with an extended blade.


----------



## goldstar31

As  I have already intimated, the little GHT is purposely designed to  part a piece of 2" diameter of mild steel. 

What more is there?   well surprising, the Late Martin Cleeve in his hints to beginners in Model Engineer, described how he parted off 3" diameter Mild steel.  It was on a part Myford ML7 because he couldn't afford a whole one-- and a mechanical hacksaw.  We  live and some of us learn.


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## goldstar31

Perhaps the topic should be:-

'How to sharpen and then hone a hss lathe tool'. and then
the Past master's one of------'How to do it all on a parting tool'
and then----- Oh no-- How to make a Quorn tool grinder

Wasser Qurn thing- mista? Like, you know all those funny ball handles that look like shaking hands with an octopus.  LOL Tellus, tellus


----------



## jackary

What about this "vertical" parting tool arrangement. The topslide has been wound back just enough to enable the parting tool holder to rest solidly on the cross slide, preventing any downward deflection due to the normal cantilever extension on both a front or rear mounted parting tool. The topslide on this screenshot can lock the upper slide to the lower slide for the full slideway length using an oval gib arrangement. The parting tool shown can be HSS or a carbide insert just slightly wider than the mounting.
Alan


----------



## goldstar31

Myford to whom al shall pay due obeisance , toothbrushes at the slop, kitbags will not be worn and so on, produced a parting tool which cut from both sides of the lathe bed. 

Joy upon joy-- and then they went bankrupt

Hoowz zat for a memory?


----------



## Steamchick

The tool post n tool are mounted on the cross-slide on the saddle, so fewer sliding joints between the axis of the lathe and tool. So stiffer, less clearances for relative movement,man less chatter,
k2


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## BaronJ

jackary said:


> What about this "vertical" parting tool arrangement. The topslide has been wound back just enough to enable the parting tool holder to rest solidly on the cross slide, preventing any downward deflection due to the normal cantilever extension on both a front or rear mounted parting tool. The topslide on this screenshot can lock the upper slide to the lower slide for the full slideway length using an oval gib arrangement. The parting tool shown can be HSS or a carbide insert just slightly wider than the mounting.
> Alan



Hi Alan,

That looks reminiscent of the sort of method used on auto or CNC tool changers.

However it doesn't get you away from the play in the cross slide.


----------



## goldstar31

BaronJ said:


> However it doesn't get you away from the play in the cross slide.



Theoretically, a normal and a larger cross sectional area should be more of a problem than a very much thinner parting tool blade.  The only serious concern is a thin blade being damaged or broken by swarf binding. IMHO, this is why a very experienced professional machine shop OWNER ground a kerf on the thicker bit of the parting tool, angled it all at 7 degrees to minimise  'having to grind another kerf' and then created a 12 degree and male vee shaped  cutting edge.

But no John, people seem incapable or unwilling  to follow logic and get their money out but rely on some far less able - perhaps nobody, as their mentor in a correspondence course.

I'm going on, 

Norman


----------



## fcheslop

I now use chip breaker blades as they are cheap enough and long lasting and it saves this lazy beggar having to grind them up








						Spare Chipbreaker Blade 2 mm thick x 8 mm wide x 80 mm long. M-35 HSS with 5% Cobalt - Chronos Engineering Supplies
					

Spare Chipbreaker Blade 2 mm thick x 8 mm wide x 80 mm long. M-35 HSS with 5% Cobalt from Chronos Engineering Supplies. Free UK delivery and great worldwide rates.




					www.chronos.ltd.uk


----------



## bikr7549

I have been frustrated by the cut off operation, but recently it has all changed for the better. I came across an idea for a tool holder and tool alignment on the lathe that has made this operation a dream! A YouTube video on the holder and one on cut off tool alignment are below, and I cannot believe how easy this has become. Aligning things so that there is minimal torque on the tool might have helped operations without making the new holder, but I decided to try it with the new holder (and a narrower T type blade). In retrospect I bet much of my troubles were due to the tool holder (a quick change type) being off to the side-now the tool holder sits close to the center of the rest. I don't think he mentions why he has the compound adjusted to be perpendicular to the lathe axis, but I did this as well. Check it out. The holder was pretty easy to build, maybe 4 hours of work-I used my new Harbor Freight 4x6 saw to make the clamping slit, and it worked like a charm-I am pretty happy with that saw so far.


----------



## bikr7549

Here is a top view of my new holder.


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## SmithDoor

It is used for products work for speeding up work. 
The only time I have used back cutoff .
But you do need to a lot of parts and do setup right. 
Since most my work is 1 to 5 parts and a fast change tool post is faster.

Dave 



almega said:


> What are the benefits (or disadvantages) of rear, upside down mounting of the cutter for parting off?


----------



## goldstar31

SmithDoor said:


> It is used for products work for speeding up work.
> The only time I have used back cutoff .
> But you do need to a lot of parts and do setup right.
> Since most my work is 1 to 5 parts and a fast change tool post is faster.
> 
> Dave



Of course this is NOT home workshop! Having to 'Work' takes away whatever we we have in this limited existence
My thoughts on a mere 36 years of retirement were, on reflection, not long enough.
So back to GHT and  I had a quick look at the alternative drawings-- and note that a Mr Riley alltered the GHT turret to one parting blade and-- another lathe tool.
Somewhere else, and a long time ago, the rear turret was further modified to take things like  boring tools.
From where I sit, this parting off thing- which is merely at the making washer stage, has to advance and not only slice rectangular and irregular material but go on to such  things as making tee slots around the periphery of a rotary table or- in my case on the Quorn T&C, a continuous angle cut to add limits or stops.
As some say, it's all go!

The old site was that of a Chris Heapy, Sadly, very little seems to be left

Nornan


----------



## Apprentice707

I may have missed it, but I don't think Bikr7549 locked the carriage before he made the cuts. This is always a good idea since it gives even more rigidity. I use a rear tool post with a Ganze insert cutter which serves me well, just have to remember to check the tool height from time to time.


----------



## Steamchick

Hi Guys,
A lot of clever stuff here, and I don't doubt that you all make it work somehow. 
But just a note on parting using the toolpost mounted directly on the cross-slide behind the work-piece, the workpiece rotated "normally" and the tool upside-down. This is so that the forces through the saddle onto the bed are exactly the same (rotational torque) as "normal cutting", so you are using all the sliding surfaces on the bed as designed to resist that torque. You are NOT transmitting torque through the rotatable longitudinal top slide, which adds extra potential slack to the chain of torque transmission. And if your quick-change toolpost doesn't act as stiff as a directly mounted tool, then pit it on the shelf and directly mount the tool near tool centre. For precision machining you need the stiffest set-up possible, but for light machining you can get away with hand-held tools (It is called Graving).
Also, if you run the lathe backwards with an upside down tool in the regular toolpost, you are actually putting the stresses at saddle-to-bed and between top-slide and cross-slide all on the gib-strips - I.E. the "adjustable" parts of the slides. This is not doing you any favours in a situation when the blade chatters. The lathe was designed to work best one-way, so when highly stressed - as in parting and anything that takes a lot of torque, it is better to use it that way. 
I am not saying don't work backwards, standing on your head or with eyes wide shut, but it is better to work "forwards", standing upright and with eyes wide open.
Just do what you like doing and enjoy it.
We are only here to advise BEST PRACTICE, not smack your hands like teachers. (I sometimes break the rules myself - because I am lazy, or find it works well enough for the job I am doing - I am just a normal human that does that sort of thing, but I wouldn't advise you copy my bad practices!).
Enjoy,
K2


----------



## Steamchick

jackary said:


> What about this "vertical" parting tool arrangement. The topslide has been wound back just enough to enable the parting tool holder to rest solidly on the cross slide, preventing any downward deflection due to the normal cantilever extension on both a front or rear mounted parting tool. The topslide on this screenshot can lock the upper slide to the lower slide for the full slideway length using an oval gib arrangement. The parting tool shown can be HSS or a carbide insert just slightly wider than the mounting.
> Alan


Great. This is doing the same thing as a rear mounted toolpost - attaching the tool to the cross-slide and eliminating the twisting motion on the top-slide gibs.
I like the rear mounted tool-post, as I don't have to set anything up every time I part-off (almost every job I make from stock bar).
Remember, if the parting tool isn't EXACTLY square to the rotational axis of the workpiece there will be unwanted side forces on the blade (the cut face will be tapered or curved, not flat and true). Also a blade with any taper in any direction will cause side thrust at the cutting edge that will cause more problems than I want to consider. Goldstar is clever and can grind near perfect symmetrical shapes on the ends of his tools (from what I can glean here), but with hand grinding I would not attempt it - because of the side-thrusts that can ruin a job. Often Parting is the last operation, so you don't want to waste all the work done previously (and possibly your only bit of metal that size!).
Set right, cut once, cut right! (always Check, check, and check again.).
And ENJOY your HOME MACHINING.
K2


----------



## SmithDoor

My experience comes from manufacturing starting 1960's. Including setting up turret lathes an screw machines. Setting up Gisholt #5L , J&L #4 , B&O #3 , B&S #2 and Truab screw machines

Dave



goldstar31 said:


> Of course this is NOT home workshop! Having to 'Work' takes away whatever we we have in this limited existence
> My thoughts on a mere 36 years of retirement were, on reflection, not long enough.
> So back to GHT and  I had a quick look at the alternative drawings-- and note that a Mr Riley alltered the GHT turret to one parting blade and-- another lathe tool.
> Somewhere else, and a long time ago, the rear turret was further modified to take things like  boring tools.
> From where I sit, this parting off thing- which is merely at the making washer stage, has to advance and not only slice rectangular and irregular material but go on to such  things as making tee slots around the periphery of a rotary table or- in my case on the Quorn T&C, a continuous angle cut to add limits or stops.
> As some say, it's all go!
> 
> The old site was that of a Chris Heapy, Sadly, very little seems to be left
> 
> Nornan


----------



## jackary

Baronj wrote,

"That looks reminiscent of the sort of method used on auto or CNC tool changers.

However it doesn't get you away from the play in the cross slide. "

I agree with you Baronj but the main point of the vertical parting tool is it avoids the horizontal cantilever distance from the parting tool mounting point to the cutting tip. This horizontal distance is present in both front or rear parting tool set ups and this exaggerates any defficiences at the mounting point base or as you say cross or topslide. The vertical parting tool has solid metal support from the tip to the top of the cross slide.

Alan


----------



## Steamchick

My rear tool post is centred about 1 1/2 " from the workpiece. The engagement of the cross-slide to saddle is still the same and the same location relative to lathe axis. I can't see it matter in that the handle and part of the cross slide extend beyond the engaged part of the slides?
Tool position over the saddle over the bed should only be applying torque against the regular slide faces anyway. (Hard to discuss this without pictures).
K2


----------



## bikr7549

Apprentice707, that pic was contrived as i am not doing any parting at the moment. I do lock the carriage and tighten up the gibs when doing this operation.


----------



## bikr7549

Here are some more pictures of the setup, in particular the alignment of the tool to the cross slide dovetail. If I had tried rotating the compound axis to be perpendicular to the lathe spindle I may not have had the chatter problems as the overhang that way is much, much less. But it is even better with the new tool, almost on the cross slide dovetail centerline. Next time I need to do some parting and have the time I may go back to the old holder just to see. BTW, the new cutoff tool is about 3/32" wide, same as the old one. The new tool has a radius on the top of the tool running along its length.


----------



## tim9lives

> It does look like there is a "big brother" international conspiracy. I think it is a strategic warfare by the Chinese - where the man-made virus was initially released - to de-stabilise the Western economies, so we become more dependant on imports from China, which can then inflate prices for their goods! Maybe it isn't? Just an unhappy coincidence? But nothing would surprise me...



All types of scenarios and possibilities. Could be just a screw up which was unforeseen. Very possible that it happened just as reported, a wet market. 
That said, if any government were to intentionally want to harm Capitalism of the major Western Economies... a pandemic appears to be a pretty damned good weapon. But, next we would have to look at motivations. Personally I don’t think China would have been as motivated to do something like use a Bio-weapon as Putin’s Russia or the other two Rogue Nations like Iran or North Korea. Let’s not forget that we have UN sanctions on those three nations. Much less harm to their economies than to even China. Free Western Nations have taken a huge economic hit. 
   Furthermore, Russia has been working on Bio-weapons for decades. Russia even put bio weapons at the forefront of their triad of offensive weapons with nuclear now the last most likely weapon to use offensively.


----------



## SmithDoor

You do know it all same for CNC and Screw machines.  The only difference is one use a computer and the uses reliable cams. Turrets use a machinist.

The screw machines are fully automatic the CNC is only easy to setup but most slower since they only use one tool at time.

Dave



jackary said:


> Baronj wrote,
> 
> "That looks reminiscent of the sort of method used on auto or CNC tool changers.
> 
> However it doesn't get you away from the play in the cross slide. "
> 
> I agree with you Baronj but the main point of the vertical parting tool is it avoids the horizontal cantilever distance from the parting tool mounting point to the cutting tip. This horizontal distance is present in both front or rear parting tool set ups and this exaggerates any defficiences at the mounting point base or as you say cross or topslide. The vertical parting tool has solid metal support from the tip to the top of the cross slide.
> 
> Alan


----------



## SmithDoor

Error


----------



## nautilus29

Depending on your lathe side I would consider a thinner cutoff as well.  We also use right or left cutoffs at work where the face of the cuttoff is angled.  Another benefit from doing that is you can basically get rid of the dimple on your part.


----------



## SmithDoor

I agree something has been talked out.

I use thin blade even if say thicker blade 
Even on 2" bar stock I use ether 0.040 or 0.060 size blade 

Dave 



nautilus29 said:


> Depending on your lathe side I would consider a thinner cutoff as well.  We also use right or left cutoffs at work where the face of the cuttoff is angled.  Another benefit from doing that is you can basically get rid of the dimple on your part.


----------



## Richard Hed

tim9lives said:


> All types of scenarios and possibilities. Could be just a screw up which was unforeseen. Very possible that it happened just as reported, a wet market.
> That said, if any government were to intentionally want to harm Capitalism of the major Western Economies... a pandemic appears to be a pretty damned good weapon. But, next we would have to look at motivations. Personally I don’t think China would have been as motivated to do something like use a Bio-weapon as Putin’s Russia or the other two Rogue Nations like Iran or North Korea. Let’s not forget that we have UN sanctions on those three nations. Much less harm to their economies than to even China. Free Western Nations have taken a huge economic hit.
> Furthermore, Russia has been working on Bio-weapons for decades. Russia even put bio weapons at the forefront of their triad of offensive weapons with nuclear now the last most likely weapon to use offensively.


What abut the other rogue nation?  The biggest of them all?


----------



## MRA

What's more explosive here - talking about WMD,  or admitting that at home on a small bendy machine I often use the tailstock when I'm parting off and only withdraw (ahem) at the last moment 

It also works better if things are a bit bendy if you go really, really, really slowly (thinking speed rather than feed, though that spoils the gag a bit!)..


----------



## Steamchick

Bikr. You were right about the quick change head being a problem. Tools outside the width of the slides cause a twist that causes chatter... the new tool holder inside the width of the slide is correct.
Well done!
K2


----------



## goldstar31

[


Steamchick said:


> Bikr. You were right about the quick change head being a problem. Tools outside the width of the slides cause a twist that causes chatter... the new tool holder inside the width of the slide is correct.
> Well done!
> K2



Ken
        In your case, I believe that you have a 8 X16 lathe similar to my SiegC4.  So you can utlise the GHT rear parting tool which was designed for the Myford 7 series by the simple addition of a mild steel subplate.  The simple expedient will also allow more redly available 'Myford' stuff suchas vices, vertical slides. Mine will also take such things as my GHT small dividing head and several sizes of rotary tables.

Thought that a mention might regresh memory


Best wishes

Norman


----------



## Steamchick

Sorry Norman. I don't   know anything about MYFORD ML7 stuff. I only ever owned an ML3. They stopped making that in the 1960s anyway, and no spares or extras.
I made my own rear mount for a tool holder my father had made for his 1960s lathe (his Dad's). I had to drill and tap the cross-slide for the rr mount, as it is without tee-slots.
K2


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## Steamchick

Hi again Norman... your mention of sub-plates has prompted an idea that I could add a piece of gauge plate onto the back of the cross-slide - 4-bolt easy to dismount for working on it - so I can drill-tap for various other kit, such as fixtures for holding cylinders for boring, vertical slide, angle plates, etc.
Thanks for the prompt!
K2


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## goldstar31

Steamchick said:


> Sorry Norman. I don't   know anything about MYFORD ML7 stuff. I only ever owned an ML3. They stopped making that in the 1960s anyway, and no spares or extras.
> I made my own rear mount for a tool holder my father had made for his 1960s lathe (his Dad's). I had to drill and tap the cross-slide for the rr mount, as it is without tee-slots.
> K2


In a a roundabout way, I also used a plain unslotted plate  As for 'Archaic stuff', I  have a Perfecto vertical slide and vice- which fits both lathes and - if it warms up a bit- I am fittomg a 1950' Potts stle  vertical slide.

Norman


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## goldstar31

goldstar31 said:


> In a a roundabout way, I also used a plain unslotted plate  As for 'Archaic stuff', I  have a Perfecto vertical slide and vice- which fits both lathes and - if it warms up a bit- I am fittomg a 1950' Potts stle  vertical slide.
> 
> Norman



Apologies,  I was doing my 'Hendon Days' one finger typing--- and YOU BEAT ME


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## Steamchick

I cheated. Used 2 fingers...
K2


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