# Lathe tool grabbing and related cutting issues.



## zeeprogrammer (Sep 4, 2009)

I was turning a bit of 12L14 steel. Nothing different than what I'd done differently before. I think the tool got grabbed and dug into the steel. Stalled the motor.

Reset everything and continued turning. Initially was getting a 'smooth' finish.
Was using power feed. Suddenly, instead of a smooth finish, I got a stepped finished. Several steps. Playing around with it, it looks like the tool keeps getting grabbed a little and digs in.

At one point, I would feed in .005 and it would cut deeper than I expected. The next .005 did hardly anything. It went back and forth like that several times.

Using a carbide insert.

Kept at it cause I was pretty good along and thought I could get through it.
As usual...last step, parting off. Stalled so bad the part moved in the chuck at a slight angle. So done.

I think I still don't have the compound slide gib right. With sufficient oil along the joint you can see it move if you lift it up and down. Looking (remembering) the gib, it seemed small (height).

I've played with this thing left, right, up and down...am I looking at replacing the gib?

Certainly, parting continues to be a heart stopper (or pooper maker) particularly with steel. I'd rather not 'have' to go to a rear parter (and this time there wasn't much in the way of chips before I had problems).

Any other thoughts?

I think the part is salvageable. I think there's enough there to cut off the 'parent stock' (hee) with my handy-dandy bandsaw. Then I'll see about what it takes to clean up. Still work-able if I can't. It's the bottom of a base.

Not much information here. I don't know what might be important.

Sorry to be any 'trouble' here...but I have that reputation ;D.


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## Deanofid (Sep 4, 2009)

I don't know what kind of lathe you're using, Zee, but if you suspect the compound gib, then lock it when making your cuts. 
Also, if your lathe is one of the import units, it may help to lap the gibs so they will put even pressure on the dove tails when you adjust them.

The sudden digging in problem could be because you have back lash that hasn't been adjusted out when you start your cut, or your tool needs to be repositioned, or it is dull, or, again, loose gibs. 

When parting off, lock all your gibs except the one you are using to feed the tool, and make sure your tool is really sharp. Make sure the tool is perpendicular to the work. I would not feed with the compound, especially when parting, if you have a small lathe. Use the cross slide and lock the compound any time you can. 

(edit) Forgot one thing, (probably more than that, really). Getting "steps" or scallops on the work piece is also sometimes an indication that the spindle bearings are not pre-loaded enough. 

Dean


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## Foozer (Sep 5, 2009)

zeeprogrammer  said:
			
		

> I was turning a bit of 12L14 steel. Nothing different than what I'd done differently before. I think the tool got grabbed and dug into the steel. Stalled the motor.


 two things cause that for me. the slide gibs loosen up and/or I forget to lock down the tailstock. More often for me its the tailstock ram lock i just dont give it quite enough OOMPH. lets the piece float around a few tho and she will grab just like you described.

Robert


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## ozzie46 (Sep 5, 2009)

Did you set the parting tool dead on center to the work? If it was even slightly off center it will cause problems. Your comment about not many chips would seem to indicate the tool was either not sharp or slightly below center therefor rubbing on the part instead of cutting. The other postings about locking things up are right on target

  Just my 2 cents on the subject. I am just a newbe too and have run into the same problems. Learning to spend the time it takes with a diamond hone and a arkansas stone to get a razor sharp parting tool was my best achievement in parting ops. Resharpen often with a 7 X lathe. 

 I noticed when everything was right, turning the cross slide handwheel was almost effortless, but if the tool dulled or it was not centered you could feel the resistance.

 If others with more experience than I see anything incorrect in what I posted please correct me.

 If you have a 7 X lathe I have read that changing the spindle bearings to tapered roller bearings makes a great improvement to facing, parting and turning operations. I'm going to look into doing this to mine as well. 

 There are in fact numerous mods I plan on doing as soon as I finish my current builds.
 One of the main mods will be tapered saddle gibs.

  Man I never talk this much. Don't know what came over me.    


 Ron


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## PhiberOptix (Sep 5, 2009)

Zee, 

I agree with what everyone else has said above, 

but just wanted to add 

that some materials tend to grab more than others 

in which case I turn the coolant on full

regards
Andy


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## Maryak (Sep 5, 2009)

Zee,

Carbide inserts can appear tight but are sometimes loose in the tool holder. This allows the bit to swing about, altering the depth of cut. Check this and also that the holder is tight in the tool post.

Hope this helps.

Best Regards
Bob


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## vlmarshall (Sep 5, 2009)

Well, he's cutting 12L14...does it get any easier-cutting than that? Like Ozzie said, make sure the top surface of your cutting tool is right on the centerline of the part. It sounds like it's not cutting until you really crank on it, so it could be too low, or too dull... and that you have a bit if backlash, or gib slop, in several places adding up.

Just a thought. Good luck & stick with it, Zeep.


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## tmuir (Sep 5, 2009)

Check your carbide insert isn't blunt.

I had to change mine for the first time the other week.
I was trying to face off and end and it just wasn't working.
It was taking off more on the edge than the centre leaving me with a slightly pointed end.

I checked everything was tight, checked for play, all good.

When I looked closely at the insert I could see it was ever so slightly rounded over.
Changed the insert and everything was fine again.


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## vlmarshall (Sep 5, 2009)

...or at least a chipped edge. I can't see ya wearing out a carbide insert on 12L, but setting the tool too low will give you tons of negative rake, which could have chipped the cutting edge, and would certainly require more cutting force, as well as trying to 'pry' the spindle up and away from the cuttter.
Pictures, pictures. ;D


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## zeeprogrammer (Sep 5, 2009)

Wow thanks everyone. Loads of good help.

Thought a lot about this over night, and also talked with a friend this morning.
I think you are all absolutely correct. It's all those things.

Most of you will remember I started machining last Feb and have done only one (well two really) engines. Before the first engine I had similar issues and broke the lathe down, cleaned up, adjusted as I could, sanded and adjusted gibs, etc. Things were better.

I should have done the same before starting this engine. With more experience and knowledge I think I could have done a better job tweaking the lathe.

A quick measurement shows I can lift the compound slide up by as much as .007...you can see the gap between it and cross slide! It wasn't that bad before...I think that first big slam did something.

Moving the cross slide shows binding near my side...moves easy towards the far side. Nut needs adjustment.

Compound binds at the far left. The first time I sanded the gibs, it was on my desk. Probably not flat enough.

I haven't looked at the insert but I suspect it's damaged. I've chipped several already....probably pretty cheap ones. (Not that I'm sold on carbide inserts...I was using them partly as a test to see the difference between them and HSS.)

The parting tool not being sharp raises another question...when to sharpen..hm obvious answer is going to be 'when it's not sharp'...so let me try...how often (or after how much work) do you find yourselves resharpening tool bits (not carbide). Or do you simply hone as a matter of course?

The gib screws have nuts on them which makes locking them for cuts a bit inconvenient...oh wait...I tweaked the screws up to those kind with 'plastic' in them so they're self locking. I can remove the nut on the middle one and use the middle one to lock the slide. Right?

Spindle bearings not being pre-loaded enough scares me. What would I do to test that?

Yeah...the effortless crank turning...I certainly don't have that at some point of travel...and maybe too much at others. Learning what 'effortless' less is. Very subjective it seems.

Thanks very much all. This helps me a lot. Not just in what to do and look for but...thanks for the motivation and support.

It'll be a busy weekend...but I'll post results when I get there.


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## tmuir (Sep 5, 2009)

I've got to a agree with you on insert tools.
I never use my insert parter, I use my HSS steel ones. I have 3 of different thicknesses and threy all work great, just every now and then needs a quick touch on the fine wheel on my grinder.

I've made a few HSS profile tools and they give a better finish than my carbide ones and my silver steel graver gives a near mirror finish.

I actually went and bought some more HSS tool blanks this week to grind a couple of tools and try them against my carbide tools, especially when I found out my carbide set I can't just by the bits that I need I have to pay $70 for a full set of 8, even though I will only ever use 2 of them.


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## Deanofid (Sep 5, 2009)

zeeprogrammer  said:
			
		

> A quick measurement shows I can lift the compound slide up by as much as .007...you can see the gap between it and cross slide! It wasn't that bad before...I think that first big slam did something.



Okay, .007" is a gob of slop, in my book. It could be it's just out of adjustment. If that's not it, check the gib to see if it's really flat. You can use a straight edge to eye ball it, or lay in on a piece of glass and roll it around looking for light under it. If it's bent, it may only be putting pressure on the dovetail in one place. 
Lap it using wet-n-dry paper laying on a pane of glass until all mating surfaces are flat. If it's a brass gib, this won't take long. If steel, work at it. 



> The gib screws have nuts on them which makes locking them for cuts a bit inconvenient...oh wait...I tweaked the screws up to those kind with 'plastic' in them so they're self locking. I can remove the nut on the middle one and use the middle one to lock the slide. Right?



That should work. Adjust the screws on the ends and then use the middle screw for locking the gib when it's not in use.



> The parting tool not being sharp raises another question...when to sharpen..hm obvious answer is going to be 'when it's not sharp'...so let me try...how often (or after how much work) do you find yourselves resharpening tool bits (not carbide). Or do you simply hone as a matter of course?



Do you know the "finger nail" test? To see if your HSS tool is sharp, run it across your finger nail. It should dig in with little pressure, and if you just swipe across the nail, it should bring up a little chip. This is good way to judge sharpness, but take care not to jam it into your finger!

I suppose we all have our way of doing things. I hone parting tools almost every time I use one. Just a touch on the stone to spiff it up a bit before I mount it on the slide for cutting. A parting tool is the most picky of them all, especially on a small machine. Get it sharp, get it square, get it level.



> Spindle bearings not being pre-loaded enough scares me. What would I do to test that?



Don't be skeert! See what your manual says about it. If you don't have a manual, identify your lathe for us and hope someone with the same lathe will know how to adjust them.  You can usually get some idea by chucking a piece of stock and letting it go about one inch past the chuck jaws. With an indicator on it, lift up on the chuck and see how much it deflects. Then push in and out on the chuck. You shouldn't be able to feel any play at all. Put the indicator on the face of the chuck and see what it does when you push in and pull out on the chuck. Shouldn't be hardly any readable amount of play. Tenths, maybe. If you're getting .001" or more, the bearings probably need to be snugged up.

Dean


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## zeeprogrammer (Sep 5, 2009)

Thanks for the additional tips.

tmuir: I might not have been clear about the parting tool...it's an HSS 'knife' blade from LMS. At some point I have to grind and sharpen my own bits...I've been avoiding it up to now. In part because I want to make an engine...not a tool. Short-sighted I know.

In any case...I have little confidence when it comes to free-handing stuff. I've seen some interesting posts on making jigs/clamps/holders for grinding tools. I hope to look into that shortly. I'll have to set up the grinder properly too.

Dean: Yeah I think that big bang meant something moved quite a bit. (Not that the lathe didn't need adjustment anyway.) Finger nail test is a good tip. Always hard to know when things are right when there's little or nothing to compare to. As for the spindle...it's a mini-lathe 7x14 (HF, Grizzly, ToolsNow, Cummins, and so on.) The manual is little more than a pic with names for things. I haven't looked at the manual but looking at the lathe I don't see any way to adjust the spindle. I'll do the test you suggested. Just a quick hand shove makes me think it's pretty solid. No...I think the issue is around the saddle, compound slide, and cross slide...needs a lot of work around there. I hope I didn't bust something.

I'll keep the thread posted.

I'll try and take pics...but camera has been absconded with by other family members to take pics of first grandchild. They apparently don't understand what's important. :big: The child will grow despite us. While I, without my lathe, will languish.


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## Deanofid (Sep 5, 2009)

Zee, we don't want you to languish. I don't have this type of lathe, but there are a number of owner websites that tell quite a lot about it. Check this guy for starters:
http://www.mini-lathe.com/Default.htm

And there is a Youhoo group that probably has many members that can tell you all you want to know;
http://groups.yahoo.com/group/7x12minilathe/?yguid=339832710

Dean


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## mklotz (Sep 5, 2009)

> In any case...I have little confidence when it comes to free-handing stuff. I've seen some interesting posts on making jigs/clamps/holders for grinding tools. I hope to look into that shortly. I'll have to set up the grinder properly too.



Wagner's music is far better than it sounds and free-hand grinding is far easier than it appears. Next time you buy metal get a length or two of 1/4" square keystock or just plain 1/4" square steel. Cut off a piece about the same length as an HSS tool blank. Decide a priori on a shape you want to grind on the end of your ersatz tool blank. Some suggestions:

an end that looks like a cold chisel or a big screwdriver tip
a hexagon
a triangle

Don't think about anything other than your intended shape and get grinding (safely - no gloves, good face/eye protection). You'll be amazed how quickly your hand-eye system will begin turning out something that looks remarkably like your goal.

After you have a bit of confidence in your ability to grind shapes, try copying by eye one of your commercially ground bits. Don't worry about precise angles and all that nonsense; just grind until it looks about right. (There's a lot of latitude in those angles for our purposes.)

Repeat these exercises about three times with sessions separated by a day or two. Save your efforts from each session and compare them at the end. You'll be able to see your progress.


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## tmuir (Sep 5, 2009)

zeeprogrammer  said:
			
		

> Thanks for the additional tips.
> 
> tmuir: I might not have been clear about the parting tool...it's an HSS 'knife' blade from LMS. At some point I have to grind and sharpen my own bits...I've been avoiding it up to now. In part because I want to make an engine...not a tool. Short-sighted I know.



Is this the type you are using?

http://cgi.ebay.com.au/NEW-PRO-T-TYPE-PARTING-TOOL-LATHE-CUT-OFF-TOOLS_W0QQitemZ170376877018QQcmdZViewItemQQptZAU_BnI_Woodworking_Metalworking?hash=item27ab40d3da&_trksid=p3286.c0.m14

If so they are dead easy to sharpen.
If not I recommend them
If you are only using it on brass you don't need any top rake and just need to sharpen the front so the bottom has rake backwards.
The good ones are wider at the top than the bottom so you don't need to put on any side rake.
Most important you set it at centre height.

I have 3 of these in holders of different thicknesses with the smallest being 1/16 inch which is great for undercutting the thread on bolts to allow them to screw right up.


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## doc1955 (Sep 5, 2009)

Reading this thread I would bet that your spindle needs a little more preload on the bearings. If you spindle has not enough it is next to imposable to part anything off and you will get chatter in turning. If you put an indicator on the spindle and what I did to check it was to move tails stock up and put pressure on headstock with it the indicator should hold steady. We had this trouble several times in my 35 years in the tool room and it is easy to fix.

Good luck
Doc


PS in sharpening a partoff blade make sure you do not over heat it in sharpening keep water handy and keep it cool if it shows any sign of discoloring it will not hold and edge and will dull quickly.


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## zeeprogrammer (Sep 6, 2009)

Dean: Yeah...the mini-lathe site was one of the first I came across. I'll be reviewing that shortly.

Marv: Thanks. And however long it takes me...you already know that I'm going to work on making my own tool bits. As for Wagner...I have no real favorite...too many great ones...although I can say that Carmen is my favorite opera. Too bad it was ruined by that silly TV show. I used to play it in the morning to get me going. (Don't ask me anything about classical music...my problem is I remember the music...or the story...I can't seem to remember titles, authors, etc.) Kind of lousy.

tmuir: I think yes they're the same or very similar. But only similar. Your comments make me think I have some learning to do. I have 3. 1/16, .04, and .03. Same holder.

Doc: Thanks for the tip. Not sure about spindle being the problem. At least, I don't think it's the major problem 'du jour'. Not to say it needs adjustment...but I think the bigger problem is the compound slide...certainly I can see a large amount of play there. But I need to check everything now.


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## tmuir (Sep 6, 2009)

zeeprogrammer  said:
			
		

> tmuir: Your comments make me think I have some learning to do.



Don't worry so do I.
My brother in law asked me today if I could turn a part that will involve me turning a thread on the lathe. Thats something I wasn't planning on learning how to do for a while yet.
I've got so many other things I need to learn before hand, but isn't that all part of the fun?


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## joeby (Sep 6, 2009)

Zee,

 I don't have any experience with the type of lathe you have, but I do have a 109 and a 12x36 Atlas, neither of which are considered overly rigid machines.

 A couple of things that need to be in the back of your mind when using these smaller machines for parting:

1. Part off as close to the chuck as you possibly can. I leave just enough out of the jaws to let the toolholder clear the jaws.

2. Sharpen the parting tool on the end only, if they are the commercial blades, the side clearance is already there. You can grind a slight angle on the end so that the right edge of the tool is ahead of the left edge, that way your part is cut off clean and the "pip" will be on the end of the bar.

3. Make sure you have the tool as much over the center of the cross slide as is possible, not overhanging the left side. This will help keep your cross slide from tipping under tool pressure. 

4. Make sure your parting tool is on center and square to the spindle. I bump the side of the parting tool against the chuck face (spindle off, of course) before tightening the toolpost.

5. Keep the tool overhang to a minimum. If you are parting 1" material, you only need 9/16 - 5/8 of parting tool sticking out of the toolholder.

6. Run a lower spindle speed.

7. Use cutting fluid or coolant. I use sulphurized thread cutting oil, messy and kind of smells but works well.

8. I try to avoid using the three jaw if I need to do a lot of parting off, especially on larger diameter work. The four jaw supports the work much better than the three jaw.

9. If you are parting brass, try stoning the front edge of the parting tool to make the cutting edge a little blunt. Works the same way as "dubbing" the cutting edge on a drill, preventing it from pulling into the work.

 I hope some of this helps, some has already been mentioned, all good advice. 

 Take care of the machine problems first though.

Kevin


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## zeeprogrammer (Sep 6, 2009)

Thanks for all the good tips Kevin.

I didn't know about #2 (angle) or #9 (dubbing).
But where I've had a lot of trouble is #6 (spindle speed).
Too slow and the motor stalls. Happens 'often'. So far I've been cranking up speed to get past it. But it may also be a tool not sharp enough. I do use cutting oil.
Still very new to this so I'm still developing a 'feel' for it.

Thanks.


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## joeby (Sep 6, 2009)

There is one of the little issues with speeds and feeds when turning, the work diameter keeps changing! With milling, the tool diameter, and therefore the surface speed, remains the same until a tool change takes place. In turning, if the work changes diameter, the surface speed does too. If you start facing or parting on a 2" diameter part and leave the spindle speed alone, you are turning way too slow at the center.

 CNC machines can deal with this with CSS, or constant surface speed, which increases spindle speed with decreasing diameter.

 Manual lathes are a little tougher to deal with. You need to pick a happy medium, where the spindle speed is not too fast to cause chatter or "grabbing" at the larger diameter but still fast enough to reduce tearing of the material at the smaller diameter. With your spindle speed fixed, then you need to vary your infeed to suit. Think of the chipload, at the larger diameter the surface speed is higher so if you want to feed at .005 per revolution, you've got less time to move the cross slide .005 than you do at the smallest diameter. You, as a result, need to slow down your feed as you get closer to center.

 As with many other aspects of machining, it will come to you as you go along. You will start to get a feel for what the machine and material are telling you.

Kevin


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## Joe Rollings (Sep 6, 2009)

One of the easier ways to establish tool height is to move the parting tool up to the work and put a small metal bar, like the 6" scale or ruler we carry in our pocket for measuring and swizzle stick use, between the bar and the tool, then roll the cross slide forwards until the scale is trapped bewtween the tool and the workpiece. A glance will tell if the tool is standing straight up or is tilted. If it's straight up and down, your tool is on center.

In my mind, carbide is a production aid, and if one is not doing production, it's more trouble than it is worth, although I am aware that others ( maybe SMARTER others) feel differently. High speed cutters load the machine a lot less and are more adaptable to odd demands with a bit of offhand grinding experience.

As time allows, I'll try to do a few paragraphs on offhand grinding, since that is my main occupation over the last 3 decades. Should I do it here or start a new thread?....Joe


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## zeeprogrammer (Sep 6, 2009)

Hey Kevin. Thanks. Same is true when facing.

Joe...Thanks. Yeah, I use the metal scale trick. As for posting your knowledge on grinding...I'm sure many others would be interested. But no sense their having to deal with this thread. I think a new thread on the subject would be great.

Thanks all.


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## arnoldb (Sep 6, 2009)

Zee, I'm happy to see this:


> Still very new to this so I'm still developing a 'feel' for it.



BUT: you won't really get the feel while using automatic feeds.

Get some of the bits off your wall of learning and "play" with it. Try rough and fine cuts, with deep and shallow in-feeds in different combinations. Don't use any automatic feeds - manual only and while you do the tests, try and feel how much turning pressure you need to put on the handwheels to get a cut. Try to get into a turning rhythm for the handhweels; slow and steady. 

I may be a "miscreant and barbarian"  , but one thing I figured out to get some of the finishes I've gotten so far, is that you should never have a need to apply much force to turn the handwheels to make a cut. If you need force to turn the wheels, something is wrong. Have a look at the chips coming off; you need a "nice regular 'stream' " of chips coming off while cutting. If not much is coming off, you may be rubbing; that just blunts a HSS bit immediately. If you can hear the lathe motor slowing down - that means you're being a bit heavy-handed, or the cutting bit is getting blunt - ease off then.

So far in my also "limited and young" machining exploits, I've found HSS bits to be the best for nearly all jobs. One exception to this I've found is roughing out cast iron, where tungsten tipped bits were better. BUT to get a close finish in CI, the very sharp HSS bits still won.

Grind bits of HSS "sort of" along the guidelines for the job and material (and this grinding need not be perfect -play with it!) and test different cuts on scraps.

Like other members stated, tool on center height is very important. Using a rule nipped up between stock and bit works, BUT: the thicker the stock, the less accurate this will be. Also, if the mounted stock is not already concentric with the lathe center line, this method is not accurate.Thinner stock gives a more accurate indication than thicker stock. And one that caught me: If you use an engraved rule, the engravings can cause inaccuracy; rather use an old feeler gauge or a plate without surface engravings/markings. 

Regards, Arnold


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## zeeprogrammer (Sep 6, 2009)

arnoldb  said:
			
		

> I may be a "miscreant and barbarian"



What!? Who called you a miscreant and barbarian? I'll have a word with that troublemaker...or troublemakers as the case may be. :big: And I'll use all capitals!

Thanks Arnold. Yeah. I'm just going to have to take some time off from the mill engine and work on my skills a little. (Nah...I'll probably do both. ;D)

I think the first order of business is to get my lathe in better adjustment. No point developing a 'feel' for binding if you know what I mean. I'm thinking of adding some mods too. Protect the apron gears...maybe add a rubber sheet on the carriage to keep the chips off...not sure. At least the apron gears though now that I have a bit of experience in drilling and tapping (although there's more needed in measuring :big.

I'd wondered about the engravings on a ruler...I usually take two or three measurements.


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## zeeprogrammer (Sep 6, 2009)

And so I start...

Took off the compound slide, the cross slide, and the apron.
Cleaned the saddle as well as I can without removing it.

Pic shows the 'clean' saddle...







Saddle moves left and right very easily...just give it a shove.
A little pressure from below the saddle and I get this...






Bit too much? I can get to nearly 5 thou but I was weak from a small tumbler of scotch. ;D

So going to try and adjust the screws from below yet keep it sliding easily...

I can get to 1.5 thou and still shove it left/right with one hand. Breathing on the screws seems to result in binding. Worried it might be too tight. Can't tell. No experience. Seems smooth the left half towards the head stock...a little resistance starting on the right half.

Going to leave it as is.

Next step is the cross slide...should be fun with the nut. Saw a mod where someone split the nut in two. I won't do that...need more experience.


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## zeeprogrammer (Sep 6, 2009)

Here's a shot of the carriage gears in the apron...






That's why a lot of people have added the mod to cover the apron gears.
That's why I/you/we want to as well.

Having taken it off...even more chips fell into the gears...you can feel the horribleness of it when you turn the crank. You couldn't tell (at least I couldn't) when it was still on the lathe.

Will clean it out and make a cover. Not tonight though. But I want to do that next rather than reinstall the cross or compound slides.


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## Foozer (Sep 6, 2009)

zeeprogrammer  said:
			
		

> Saw a mod where someone split the nut in two. I won't do that...need more experience.



Might be good idea to hold off on some Mods till ya scrape a few knuckles 

After all you wouldnt want this to smile upon your day






One each, genuine snapped spindle snout. Another reason why you keep precious body parts to the right of the chuck 

Was an "aftermarket" spindle that replaced one I bent last year. Small design flaw, The threaded end was cut from separate stock and press fit upon the shaft proper with the shaft itself turned down a bit to act as a stop for the threaded piece. Results very little cross sectional meat, a few good hard cuts and away she went.

Ah! now to make one of my own, knowing the weak-spot...



On your slide how much movement is there on the back side, rear slide area. Same setup as in pic but other rail. Tool bit cutting force will try to pivot the slide on the front rails lifting the slide off the rear one.

Robert


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## zeeprogrammer (Sep 6, 2009)

Foozer  said:
			
		

> Might be good idea to hold off on some Mods till ya scrape a few knuckles
> 
> One each, genuine snapped spindle snout.
> 
> On your slide how much movement is there on the back side, rear slide area.



Sorry to hear that Robert. Will it take much to make your own?

Next to no movement on the rear. You could feel it on the front...'nothing' on the back.

Please define 'few', amount of skin in whatever units you prefer, as well as amount of lost fluid - not counting those fluids lost simply due to loss of control (i.e. surprise). I'd never make a cook...'dash' means nothing to me. :big:


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## Tin Falcon (Sep 6, 2009)

that little gear cover is one of the few mods I did on my 7 x10 . I also added a little oil hole to keep the gears lubed.
Tin


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## zeeprogrammer (Sep 6, 2009)

Thanks for the tip Tin. I hadn't seen anyone do that for this mod.


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## Foozer (Sep 6, 2009)

zeeprogrammer  said:
			
		

> Sorry to hear that Robert. Will it take much to make your own?
> 
> Next to no movement on the rear. You could feel it on the front...'nothing' on the back.
> 
> Please define 'few', amount of skin in whatever units you prefer, as well as amount of lost fluid - not counting those fluids lost simply due to loss of control (i.e. surprise). I'd never make a cook...'dash' means nothing to me. :big:




Should be an easy part to make, good side is, now I have no excuses for not finishing up a few other projects need doing, like (UGH) clean the shop, stack some wood, water pump in car, put the putt putt bike back together, all the while looking for that misplaced Honey Do list.

Just dont know what happen to it. . . 


Knuckle scrapping is directly proportional to the number of works spoken when you shove you hand into a pocket thereafter. 


Getting those gears protected from the stray elements, that would be a good choice. They will take abuse but just when you least expect it, you dont want to be posting pics of busted gears


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## websterz (Sep 6, 2009)

zee, you really need to bite the bullet and make a set of tapered gibs for your lathe. It's a weekend job if you really take your time, or a one evening gig if you want to get 'er done. I made a set for my 7x12 and it instantly improved the machine by a factor of 10. There are several write-ups online about how to do it. I strongly suggest using aluminum bronze rather than brass, it is more self-lubricating and much more wear resistant. I'll be happy to help out if you need more info. While you're at it I suggest replacing the cross-slide and compound gibs with bronze as well. 

For the ultimate in rigidity improvement I suggest removing the compound and replacing it with a solid steel plinth of the same height. 99.9% of the stuff I do doesn't require taper turning capability, and I don't single point. On the rare times I do need to turn a short taper I can re-install the compound in a few minutes. The rigidity you gain (not THAT rigidity! : ) will more than offset the need to switch the compound out. Once again, I saw a 10 fold improvement in the performance of my lathe by doing this. Then of course, you all already know I am a big advocate for rear parting toolposts. ;D

Edited for typos


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## Tin Falcon (Sep 6, 2009)

webstrerz


> I'll be happy to help out if you need more info



Please post some link for all of us with 7 x 10 etc
Tin


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## websterz (Sep 6, 2009)

Tin Falcon  said:
			
		

> webstrerz
> Please post some link for all of us with 7 x 10 etc
> Tin



Here's a vid:

[ame]http://www.youtube.com/watch?v=YoxxeJ2aI2U[/ame]

and here's the thread detailing the job:

http://madmodder.net/index.php?topic=627.0

There are several good tweaks in that post, ought to be required reading for a 7x owner.


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## zeeprogrammer (Sep 6, 2009)

Robert...yeah busted gears would be a unhappy moment. Right now I think I'm getting a small jam or binding as the crank turns...usually when I want to make that last itty bitty distance and it jams, suddently lets go, and moves too far.

websterz...I will certainly look up those write-ups. 'aluminum bronze' eh? Is there a number to look that up under? I don't know the jargon well...solid steel plinth? Is there a picture? I agree with you about tapering...haven't done any as yet. And I'll take any improvement in rigidity anywhere I can. : Yep...rear parting toolpost. Need to play with what I have first...that way...when I make the improvements...I'll see them as improvements.

Thanks!

...oh and what Tin said...

awe geesh...has my typing slowed that much...I can't get this off fast enough...will post anyway...want to see that vid.


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## websterz (Sep 6, 2009)

zeeprogrammer  said:
			
		

> Robert...yeah busted gears would be a unhappy moment. Right now I think I'm getting a small jam or binding as the crank turns...usually when I want to make that last itty bitty distance and it jams, suddently lets go, and moves too far.
> 
> websterz...I will certainly look up those write-ups. 'aluminum bronze' eh? Is there a number to look that up under? I don't know the jargon well...solid steel plinth? Is there a picture? I agree with you about tapering...haven't done any as yet. And I'll take any improvement in rigidity anywhere I can. : Yep...rear parting toolpost. Need to play with what I have first...that way...when I make the improvements...I'll see them as improvements.
> 
> ...



Here's a link to the ali-bronze. A foot of 1/2" square will be plenty to do the job. The mating parts can be made out of mild steel.

http://www.speedymetals.com/pc-1998-8385-34-sq-ca-954-aluminum-bronze.aspx

A plinth is just a pedestal...a solid base to mount your toolpost on. Nothing fancy, it just replaces the compound and holds your tools at the same height. 

Sometime tomorrow I will get out to the shop and take pics of all the mods I have made to my lathe. I probably have the pics already but they are scattered all over the hard drive...

As for the rear toolpost, I part a lot of 4140 round stock, mostly 5/8" stuff. I make my own parting tools out of HSS and I can knock off a part in 30 seconds since I moved the tool to the back and added the tapered gibs. Rigidity (in my lathe  ) is no longer a problem.


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## websterz (Sep 6, 2009)

Here's another link:

http://warhammer.mcc.virginia.edu/ty/7x10/vault/Lathes/7x10-7x12-Projects/TaperedSaddleGibs/


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## zeeprogrammer (Sep 6, 2009)

Went to look at the vid...lost track of time...only got through half the thread.
Fascinating stuff.
I'll have to go back and review again.
Thanks!


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## Brian Rupnow (Sep 7, 2009)

Zee--I find parting off to be one of the more "heart stopping" operations that I have to do on my lathe. I have been most successfull when parting off aluminum to use the lowest speed available (115 RPM on my lathe) and lots of cutting fluid (sprayed from an aerosol can). My lathe has a fixed speed motor but an internal gear transmission that lets me select the correct gears for various speeds, so torque is not a problem at these low speeds. I have scared myself so many times by having the "part" in the chuck suddenly try to "walk up" and ride on top of the parting off tool when I get close to that final "seperation" that now I just get moderately close to having the part cut off, then walk the part over to the band saw to finish the cut. I have even less success parting off mild steel. Although I have never stalled my lathe, I have broken a cut off tool, and that is a "life altering" experience. My parting off tool is HSS not carbide. I find it to be VERY critical that the cutting edge of the parting off tool be exactly on center of the lathes turning access. ---Brian


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## Kermit (Sep 7, 2009)

Brian Rupnow  said:
			
		

> .... I have scared myself so many times by having the "part" in the chuck suddenly try to "walk up" and ride on top of the parting off tool when I get close to that final "seperation"



I haven't tried parting off yet.  Still to scared of it, but I have been doing lots of reading. Probably too much reading, because some of it seems contrary to other bits. Perhaps even the authors were not all of one mind on the subject.  Anyway. 

The situation you describe in the quote above. Isn't that usually caused(riding up on tool) by the tool being slightly higher/lower than center line? And my next question. When setting a tool for center line do you make a small .001 or.002 allowance for the torque twisting the tool point down when engaged in the work? Setting the tool higher than center line so that it reaches dead center when cutting?


Still so much to learn,
Kermit


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## zeeprogrammer (Sep 7, 2009)

Thanks Brian and Kermit. Your posts help a lot.

Breaking a cutoff tool...that sends shivers down my back. Very scary.

Yeah...I have had the problem where the tool gets under when I got close to center. (I'm a happy guy if there's a hole already drilled through.)

I'd be interested in what others think about setting the tool .001 or so high to account for pressure.

Thanks guys!


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## joeby (Sep 7, 2009)

My opinion is that setting the tool above center can be done to an extent, that amount depending on tool overhang and other details. The problem with being above center is that you can add to your troubles, if overdone, by the tool not wanting to cut for lack of clearance, which you would compensate for by increasing the feed pressure until the tool is deflected enough to cut. At this point the resistance is lessened and the tool digs in too deep.

 Parting tools are very strong in the direction that they need to be; but any sideways pressure or twisting can break them rather easily. Digging in and the work climbing over the tool would seem to cause both.

 To get back to the question, I think having the setup as rigid as possible will be of more benefit than setting the tool above center.

 Keep working on the setup, it will become easier, and when you are comfortable with parting you can always give trepanning a try!

Kevin


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## zeeprogrammer (Sep 7, 2009)

Poop.
Cracked the apron casting.
Not bad though. Still good.

This side of corner of nearest tapped hole...







Was drilling...I think I was heavy handed...it went in very easy...then some resistance...a 'little' more pressure (you define 'little')...heard a snap. Thought it was the bit but it was whole. Didn't see anything then went on to tapping. That probably pushed it out enough to see.

Shouldn't cause any problems though.

Kevin...thanks...yeah...I think rigidity comes first.

All: Seems to be a bit of confusion...I was 'turning' with a carbide insert. I was 'parting' with an HSS cutting tool. Something happened with the turning and caused things to get loose (non-rigid!)...then parting tool had problems....and I can't say I remember if I checked tool height...it's a quick-change and I may have just slapped it on.


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## Foozer (Sep 7, 2009)

zeeprogrammer  said:
			
		

> Poop.
> Cracked the apron casting.
> Not bad though. Still good.



Careful there fella, just cause I snap a part don't mean you have to run in that race. 

Gonna use studs in those holes? 'specially the one with the crack. Stud and loctite, tis the way now. 

But that is a curious  part supported underneath? I've cracked enough items in my day, but you sure did an odd one. Take a break for a while

Robert


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## joeby (Sep 7, 2009)

Zee,
 I wouldn't beat myself up too much over that. Easily worked around.

 I can tell you from experience that the cast iron in these machines is unpredictable at best. I had a bit of a career change this year, went from a tool/die maker to a service tech of sorts. I've drilled numerous holes in machines doing retrofits, installing scales, lube lines, etc., and it's amazing what you can/will run into. Hard spots, voids, sand, you name it.

 Kevin


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## zeeprogrammer (Sep 7, 2009)

Robert...you are the clear winner in that race and mighty big congratulations to you. ;D Be like me...forfeit.

No...just going to use SHCS...this is the lathe apron...you won't be able to see it until I take it off to adjust it again...next week maybe. ;D

Yeah supported underneath by parallels. But what you don't see is that there's another half inch of cast iron below. I think Kevin touches on it....maybe a hard spot...the resistance I felt...pushed too hard...and caused a bit of side force...crack.

Keven...see above.

Not to worry all. If you get a 'poop' out of me...I'm disappointed but not particularly upset. However, if you get poop's Dad...or worse still, poop's Grandpa...well then...best wait till tomorrow to have a chat. :big:

Thanks all.


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## zeeprogrammer (Sep 10, 2009)

Remember...it's just a cover for the gears in the lathe apron...

My first real modification of a machine!! (The mill's belt drive retrofit doesn't count...but the gear cover meant I had to drill holes in my little lathe!)

Well the rest of the holes went well. Then it was the plexiglass (maybe there was better material...but that's what I had). Two sheets...one as a spacer. First attempt resulted in shattering. Okay...not a problem...it's an excuse to get a dremel!

Second attempt went very well. I even managed to leave my trademark boo-boo. The boo-boo is at the bottom-right. I was sanding away to a line I'd made. I forgot the line was on the flimsy covering and the covering kept moving....I kept sanding to get to the line. (The trademark is nothing special...other than it's mine...even if anyone else makes similar mistakes...this one is mine. ;D)






One more word on boo-boos. They are signatures. Unique. You should always be proud of the boo-boo. Someone might be able to make the same part...but it's very very difficult to make the exact same boo-boo. I'm proud of my boo-boos. (Mind you, I'm not advocating that boo-boos are good. Guess I'm just trying to find the good...pathetic eh?)

This 'girl' may not be pretty...but she's persistent.


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## Deanofid (Sep 10, 2009)

Looks like a very sensible mod, Zee.

Yeah.. My shop is full of "signatures".

Dean


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## websterz (Sep 10, 2009)

zeeprogrammer  said:
			
		

> Remember...it's just a cover for the gears in the lathe apron...
> 
> My first real modification of a machine!! (The mill's belt drive retrofit doesn't count...but the gear cover meant I had to drill holes in my little lathe!)
> 
> ...



You'll have that lathe modded to the point it's unrecognizable before ya' know it zee! That part's more fun than actually making stuff WITH the lathe. :big:


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## tmuir (Sep 10, 2009)

Congrats on your first mod.
I still haven't been able to bring myself to drill and tap any of my machines yet.
So far I've only had the courage to dismantle the top slide for cleaning and this was because I had no choice because due to swarf under it you couldn't fix it down ir would wobble by a couple of degrees.

I will get there eventually though.


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## steamer (Sep 10, 2009)

Nice one Zee!

Didnt hurt a bit didn't it..... ;D

Dave


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## arnoldb (Sep 11, 2009)

Good going Zee.

And IMHO - ANY reason to get a Dremel is a good one. Once you have one you'll wonder how you got along without it!

Regards, Arnold


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## vlmarshall (Sep 11, 2009)

Hey, congrats! I'm still amazed those gears are uncovered to begin with.




			
				zeeprogrammer  said:
			
		

> This 'girl' may not be pretty...but she's persistent.


Ok, ok, I'm sorry I "called" you a girl... but that was all that fit in that sentence. ;D


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## zeeprogrammer (Sep 11, 2009)

Dean: Yeah, several examples of this mod around. I put the apron back on last night (after twice having to dismantle it...once because the shield was up against the half-nut and it wouldn't budge and once because the gear to the crank handle stuck out too much) Much smoother now. Can't wait to reassemble the rest.

websterz: Now I find myself thinking about those tapered gibs every time I move the carriage. But must get back to the mill engine.

tmuir: Yeah. It was the top slide that got me started down this road.

Dave: Well...the wallet wasn't too happy. ;D

Arnold: Yeah. The intent was to go to store, get in and get out. If I spend too much time there...I spend too much.  Still, I found myself looking at all the Dremel goodies.

Vernon: Will the name calling on this forum never cease? :big:

Thanks all.


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## mklotz (Sep 11, 2009)

Zee,

Before you actually buy a Dremel, ask around the forum for opinions on which type to buy. I have four of them and each one has its advantages and shortcomings.


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## tmuir (Sep 11, 2009)

I don't know about elsewhere but where I am official Dremel accessories are outrageously expensive.

Its actually cheaper for me to go to the jewellers supply shop and buy professional buffing wheels, grinding disks, drills that will fit the Dremel over the official tooling.
This is about the only thing at the jewellers supply shop that is cheaper than elsewhere


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## zeeprogrammer (Sep 11, 2009)

mklotz  said:
			
		

> Before you actually buy a Dremel, ask around the forum for opinions on which type to buy. I have four of them and each one has its advantages and shortcomings.



Too late! Well...only so far as waiting to buy a Dremel. Opinions would be welcome.

I went for a low-end one as I didn't think I'd be using it much. I was, however, a bit mesmerized by a couple of accessories...in particular a plunge router. Thinking...hm...how might I use that. And then today...I'm at a hobby shop scrounging for any kind of 2-56 and 4-40 screws (I won't say why)...and I see a router table for a Dremel. Hm...how might I use that?

Any way...further down the road. If the Dremel I got proves insufficient...I have a son-in-law who's drooling over it.

Not knowing what I'll eventually do with it...I didn't want to expend too much for too much.

tmuir: I was more surprised at the cost of the individual bits and ends rather than the tool. It's definitely one of those tools where they get you with add-ons and accessories.


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## mklotz (Sep 11, 2009)

Dremels...

The battery powered ones are handier than a shirt pocket. I keep two on my workbench preloaded with the bits I use most (Cratex point and brass wire wheel). However, IMO, they don't have the power of the 120v plug-in model. I use the latter with the various accesories I've built (detailed elsewhere in this forum). The router attachment is handy by itself but, as I mentioned before, the clamp it uses to hold the tool can be (non-destructively) detached and used to hold the tool in various other self-made holders and jigs. You'll quickly find that, although the Dremel is sold as a hand-held tool, it's much more effective if bolted down and the work brought to the tool.

I have one with the attached flexible shaft. Since the shaft handle is cylindrical, it's much easier to mount this to the lathe toolpost to do various grinding and shaping chores.

Dremel accesories are expensive but you don't need that many. The rest you can pick up at various import suppliers or make yourself (all my precision sanding/grinding disks are homemade). The most important ones to buy, IMO, are:

The hand-tighten chuck - buy two and make a super pin vise out of the extra. As usual, nobody can bear to standardize the shaft sizes so, if you're going from tool to tool and don't want to waste time swapping collets, this accesory is golden. I wouldn't trust this chuck at the very highest speeds, however.

The right-angle attachment - depends on the type of work you do but this has served me well both while making models and also doing repairs around the house.


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## zeeprogrammer (Sep 11, 2009)

Thanks Marv.

I went with the 120V version. While battery can be convenient, it just seems I'm always picking up a battery powered something to find it's out of charge or, in the case of 'standard' batteries, someone has stolen the batteries.

Bolted down...yep.

I saw the flexible shaft at the store...almost bought it...but again, until I see my use reach some critical point...I can wait.

Repairs around the house...I thought that was what son-in-laws were for.


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## zeeprogrammer (Sep 12, 2009)

Started work on the cross slide.
Plan is to take apart, clean, put together, install, and adjust.

The last time I did this, the gib simply fell out.
No falling out this time. Couldn't budge it with fingers either. Hm.
Loosened gib screws and then the gib was free.

It appeared as if the gib screws had dug in (partially threaded themselves) into the gib. [EDIT: Didn't thread themselves. The ends of the screws are not threaded but are a smaller diameter than the screw itself and hence the original screws. Small enough that they actually dug into the gib - sort of like a press fit.]

Is this 'normal'?

The gib screws were replaced several months ago from a 'tweaks' kit I got from LMS. The screws have that bit of plastic along the thread so a nut is not required.

Could I have screwed them in too tight when trying to (learn how to) adjust? Very possible. I had all sorts of trouble adjusting this and can't say I was happy with result.

Anyway...now to find something flat to lay down some sandpaper and smooth the gib. I don't think I'll go the way of modding the nut in the cross slide (i.e. cutting it in two). I need to build more experience first.


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## zeeprogrammer (Sep 12, 2009)

Just a note to other newbies like me...

When I first got my lathe...I knew virtually nothing about machining or things very mechanical. (Not a complete dunce mind you...but it was all self-learned.)

Anyway...first job was to clean up and adjust the lathe. There was much about it I didn't understand. For example, using two opposing screws as an adjuster. So I did the best I could.

Now I'm in the process of breaking down, cleaning, assembling, and adjusting the lathe. I can see I've learned some things since last time. (Many many thanks to this forum.)

My point being...when starting out and learning...it's worthwhile to do this more often. You learn more and get a better operating machine. I should have done this after my last engine before starting another.


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## zeeprogrammer (Sep 12, 2009)

Done. He said.

All put back together.
More rigid. More smooth. And clean.  I wish I could same the same for me. 

Investigating the compound slide revealed the gib to be offset by about 0.1 inch.
That is, I could see the dig-ins from the new gib screws (same as what I mentioned before). I don't know if that was part of the problem or if the thing jammed somehow. I suspect it was poor assembly the first time.

Was a little more careful this time and the left/right movement is much much better than what I'd remembered.

Things seemed pretty tight yet smooth. Happy. Then I put the QC tool back on. When I apply front/back pressure to that...you can see the gap appear again between the compound and cross slide. This is what I had described before.

This time not nearly so bad but I don't think I can really do much about it. I haven't come across any mods that address this. (I'll just leave that little opportunity lying there. ;D)

However...by tightening up the center gib screw, I can't push the QC and get a gap. Some of you have mentioned tightening the center gib screw before cutting so I think that's what I'll have to remember to do. Particularly when parting...it's critical then.

Thanks all. I've enjoyed this and learned a lot from the experience and the members.


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## mklotz (Sep 12, 2009)

I replaced the center gib screw on my compound (admittedly an entirely different lathe) with a small finger screw that I made. Not needing to use a tool to tighten things makes it more likely that I'll lock it when it's appropriate to do so.


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## zeeprogrammer (Sep 12, 2009)

mklotz  said:
			
		

> I replaced the center gib screw on my compound (admittedly an entirely different lathe) with a small finger screw that I made. Not needing to use a tool to tighten things makes it more likely that I'll lock it when it's appropriate to do so.



I remember you talking about that. I expect to do the same once I've used it enough to develop a feel.

Thanks Marv.


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## arnoldb (Sep 12, 2009)

Good going Zee.

Did you check the tips of the screws while they were out ? - they should be smooth and possibly rounded or pointed depending on your lathe...
On my lathe, the gibs have concave dimples in them where the screws meet them, and the screws have rounded tips - which makes adjusting easy, and does not "eat" into the gibs... - just a thought.

Kind regards, Arnold


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