# Building a 56mm boring head



## arnoldb (Aug 1, 2010)

One of the accessories that's lagging for my mill is a boring head.

I could buy one, but that would not be nearly as much fun as building my own; some of you might have guessed by now from previous projects that I like building my own tools ;D

Once again, Dean's boring head build serves as an inspiration, and I'll also build my unit based on Steve C's (walnotr) plans; changed to meet my requirements - Thanks guys!

Some of the key areas of departure from Steve's plans for me will be:
1. Size - I'll be building at about 150% of the original size. This is for a couple of reasons; I have a bigger mill, so could do with a bigger boring head. The boring bar set I have has 12mm shanks, so the head needs to be bigger to accommodate this.
2. Metric - I prefer to work in metric, so the head's leadscrew will be metric. I've chosen a 0.5mm pitch for it, as it means that for every full turn of the screw, the head will be offset by 0.5mm - and thus take a cut of 1mm in diameter from a workpiece. Also, all screws used will be metric.

The mounting for the boring head had me thinking for a bit as well; initially, I considered fitting it with a 16mm shank to use in the mill's collet chuck, but that is not the best option. So I'll settle for making the shank MT4 to suit my mill's spindle directly - that would be the best long-term solution.

I'll be posting "warts & all" - so some members might be bored with the build; my apologies for that in advance.
And any suggestions and/or questions during the build is welcome!

This is what I have to start off with in terms of materials:





A bit of 32mm HRS rod for the MT4 shank, a bit of 60mm cast iron for the body (I might not use this; I'll try and find steel instead), a bit of 60mm steel offcut for the slide/holder, bits of brass for the gib and lead screw retainer, and silver steel for the leadscrew.

As I'm still trying to find some steel for the body rather than use the cast iron, I started off with the shank today. The rod I have is pretty close to the size needed for an MT4 adapter, so there's not a lot of room for removing material, but the surface scale has to go. First I center drilled one side of the 32mm rod as accurately as possible for tailstock support by clamping the stock upright on the drill press - this will become the "thin" end of the taper, as it is not spot-on center.  I know the inside jaws of my 3-jaw chuck is pretty accurate at this size, so the end in the chuck would be very close to centered. Here I've turned down some of the scale - as you can see, the bit close to the chuck is more on center:




At this point I stopped turning down the scale, as I didn't want the bit close to the chuck turned down any further.

Next I turned a section at the tailstock end down to 24mm - below the minimum that would be needed for the taper:





This end will become the "Draw-bar" end of the shank. Once there is a taper in play, workholding becomes difficult, so I decided to finish the draw-bar end completely, including threading it. With a long overhang needing support and working from the end, I brought out the fixed steady. It's one of those accessories that's seldom seen in use, but can be worth its weight in gold when needed. Here I'm setting it up - with the workpiece supported by the tailstock center, it's easy; just push each of the steady "fingers" lightly against the turned flat and tighten up the fingers:





A squirt from the oil can to lubricate the steady fingers, and a reduction in speed (I work at a slower turning speed when the steady is in use), and I could drill the end out to 10.2mm for a good depth - about 60mm deep. This is for tapping M12 drawbar thread. Then, with the topslide set over to 30 degrees, I turned a good bit of taper (about 14mm OD at the end) on the end with a boring bar:





Next I tapped the thread - I started of with the #1 12mm tap gripped in the tailstock chuck, and threaded in for a bit - this was to make sure the thread is started straight. Then I just opened the chuck, added the T-handle, and continued:




The taper tap was followed by the 2nd and 3d taps as well.

I then reversed the workpiece on the lathe, and set up the fixed steady on the "clean" bit that was close to the chuck earlier.
This is where a seldom mentioned bit of using fixed steadies comes into play. They are GREAT for getting an accurately center drilled workpiece at a distance away from the chuck. The workpiece is just very lightly chucked initially, and the steady fingers closed a bit at a time, followed by manually turning the chuck through a full revolution after each adjustment. The workpiece was off-center at the steady end completely - by about 1.5mm, but the gradual closing of the fingers and the fact that it's lightly gripped in the chuck causes it to center on its own. 
Once all three of the fingers were lightly in contact, the chuck was tightened up a bit more; not too much though; just tight enough to grip the workpiece for center-drilling it. Even if the steady fingers keeps the workpiece slightly off-center, a good center hole is drilled; it will just be a bit over-size ;D:





You may be wondering by now why I made all the boo-hah about boring an oversize 30 degree angle on one side of the workpiece and then going through the process of setting up the steady to drill the center hole on the other end...
Well, it all was to get to a point where I could mount the workpiece between centers:




Instead of fussing around with binding wire, I just used a cable-tie to tie the drive dog to the catch-plate.

And why did I need it between centers? - well, to turn the taper... I'm fortunate that I have a taper turning attachment (TTA) for my lathe. Setting over the topslide was not an option for an MT4 taper; the topslide does not have enough travel to turn it. And I needed a way to reliably take the workpiece off the lathe to test it in the milling machine spindle for fit. Did I mention that this is the first time I've tried to turn a Morse Taper ?

For the first time since I got my lathe, I'm using the TTA - well for it's intended use anyway; it's a great place to mount a magnetic base for centering jobs in the 4-jaw chuck otherwise . My little "Engineering Black Book" gives specifications for MT4 in metric, so I used the specs to calculate that I would need a taper of 5.124 mm for a travel distance of 100mm (I think this is right; the black book is in the shop now!) Well, there's no way I can measure accurately to 1/1000th of a mm, so 1/100 and an eyeball deviation on the DI would have to do. This is the setup I used:




The dial indicator is mounted on the TTA link to the cross-slide, as squarely and on center to the workpiece as I could get it by eye :big:, and run over a measured 100mm "clean" bit of the workpiece to get the readings and set the TTA. Not very professional, I know, but I think good enough for "close enough"; it's not going on a space mission.

I started cutting the taper, and after the second cut things looked wrong. The taper was WAAAY too steep!. I had the correct figures, but forgot to halve the diameter while setting the TTA :-[. Fortunately, there was more than enough un-turned stock available to re-set to cut at half the angle. Just more work to get the TTA set.

Things went well from there, and I cut close to size. Then I did a test. First some (too much!) Prussian Blue on the shaft:





After a light fit-and-turn in the mill spindle:




By no means perfect, but close enough for me. You'll see that the contact area on the larger diameter was closer, meaning that my taper is slightly shallow - but pretty close.

At least the shank sits in the mill on its own with just a light push; pretty much the same as the rest of my mill accessories:




I had to use a hammer with the draw-bar to tap it out, so as far as I'm concerned, the fit is a good 'un.

While dismantling the cross-slide to TTA link, I brushed my thumb knuckle across the slot linking the two... The Myford tooling is invariably very well machined and finished with all sharp edges removed, but someone didn't take the sharp edges off that slot...  I'll have to now :big: With red stuff leaking from the skinned bit of said knuckle, I called it quits for the day - Not much to show, but some progress none-the-less:





Regards, Arnold


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## walnotr (Aug 1, 2010)

arnoldb  said:
			
		

> Once again, Dean's boring head build serves as an inspiration, and I'll also build my unit based on Steve C's (walnotr) plans; changed to meet my requirements - Thanks guys!



Looks like a great start. Glad you are able to get some ideas from my little boring head design. Don't you just love making tools to make tools to . . . ? :big: :big:

Steve C.


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## SAM in LA (Aug 1, 2010)

Arnold,

Be careful not to leak too much of that red stuff in your shop.

There is nothing boring in regards to your boring head build.

I enjoy your posts and will be following along.

Regards,

SAM


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## ksouers (Aug 1, 2010)

Ruh-roh! Arnold is building tools again.

This is gonna be fun. 

Sorry to hear you sprung a leak. I really hate burrs, they drive me nuts.
Leaving burrs on tools is just unfathomable, it makes me wonder where else they cut corners.

Anyway, I'm along for the ride. Thanks for driving, Arnold ;D


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## zeeprogrammer (Aug 1, 2010)

As usual, an interesting read. Both educational and self-confidence building.
Sorry about the thumb.


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## tel (Aug 2, 2010)

> Leaving burrs on tools is just unfathomable, it makes me wonder where else they cut corners.



... or fail to, as they case may be! 

Great start Arnold, I'm along for the ride as well.


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## T70MkIII (Aug 2, 2010)

Sorry to hear you leaked some Prussian Red. 

I'm tossing up making or buying a boring head, so I will be following your project closely. Thanks for sharing with us.


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## arnoldb (Aug 2, 2010)

Thanks Steve! 





> Don't you just love making tools to make tools to . . . ?


 - there will be quite a bit more of that associated with this build :big:

Sam, Kevin, Carl, Richard - thanks for the enthusiastic and positive replies ;D

Tel, Rof} You're sharp as ever; Thank you, your comment lifted a bad start to a Monday morning considerably!

Fortunately the thumb is not that bad; less damage than Shrek the Gray causes when he gets in a bad mood :

No shop tonight... have to do some chores.

Regards, Arnold


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## BillTodd (Aug 2, 2010)

Watching with interest (loved the rotary table thread ).

Boring only or Bore and facing? Arnold.

Bill


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## walnotr (Aug 2, 2010)

The drawings of the original boring head have been uploaded into the download area. 

Steve C.


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## bentprop (Aug 2, 2010)

Not wanting to hi-jack your thread,Arnold,but there is one thing about boring heads that ,to my way of thinking,limits their usefulness.
Am I correct in thinking that they are "traversed" using the Z axis of a milling machine?
If that is the case,how do you get a smooth bore?Unless you happen to have a powered Z axis,it seems to me the boring head relies on the smoothness of the operators movements.With the weight of the whole mill head,etc.,this would seem a little problematic to me,especially since mine is not exactly super accurate.
Please enlighten me,fellows,and edumacate a dumb dutchman :big:


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## Deanofid (Aug 2, 2010)

You're off to a roaring start on another very useful shop tool, Arnold. Pretty soon, you
will be so well equipped you won't have anything to do but build engines! 

I hope it's okay that I note something that may be useful; Normally, when you are checking
an external taper for fit using a known internal taper, you would put the prussian blue in the 
interior taper, and test your piece. The inside of the taper would be covered with a light coat
of blue on the whole surface, and the clean external tapered piece to be tested will be carefully
inserted into the inside taper.  A turn on the piece being tested will tell the tale when it's withdrawn.

For our forum members; Steve Campbell is the fellow who designed the boring head shown on
my website. I just want to be clear that he's the guy who designed it, and provided me with the
prints. Thanks again, Steve.

Dean


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## walnotr (Aug 3, 2010)

Deanofid  said:
			
		

> For our forum members; Steve Campbell is the fellow who designed the boring head shown on
> my website. I just want to be clear that he's the guy who designed it, and provided me with the
> prints. Thanks again, Steve.
> 
> Dean



You are welcome Dean (and others). As you will note, the title block on the drawings bares the name "Open Source Tools". It is my way of giving back to the model engineering community at large. I am happy to share anything I have designed, and in the spirit of the now old computer user groups, freely give my designs for non-profit use.

The drawings in the download area have the latest changes to the drawings. I always find something to change when a drawing is revisited.  ;D

Steve C.


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## FIXIT (Aug 3, 2010)

Arnold
    Don't apologise for your 'warts&and all' presentation as it really helps "learners" like me as it's like looking over your shoulder rather going from one thing to another and thinking 'how did he do that !!'
which is obvious to the experienced chaps,  so keep it up and thanks.

Steve


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## arnoldb (Aug 3, 2010)

Thanks Bill; this one will be for boring only. Though it could be used for facing it will be (hopefully) more of a precision tool and treated as such, I generally use a fly-cutter for facing - though I have considered knocking up a TCMT facing cutter for facing HRS and tougher materials like stainless...

Steve C. - once again thank you for your generous contributions to our hobby :bow:

No problem Hans - thanks for checking in and asking! I'm not sure what mill you have; a boring head is usually used with the quill feed on a mill with the head locked in place - thus no weight from carrying the head. While manual, it just becomes an exercise in feed control; just like a manual feed on a lathe or the mill's X and Y. I don't have power feed on any of my machines (I can do it with the lathe carriage, but it's a pain to set up so I use it very rarely), so I've gotten used to try and do smooth manual feeds. If your mill does not have a separate quill feed, it might be more tricky to use though. Oh, and don't worry, for a Dutchman you appear to be very intelligent!  - I've also been called a Dutchman because my native Afrikaans is pretty near Dutch as a language!

Thanks Dean  - you should see my "tools to build" list though... And of course its OK - all contributions are welcome! Thank you; I've filed your notes on checking a taper for future use 

Steve (Fixit) - Thank you - that means a lot. And please feel free to ask questions if you want to; I'm happy to try and answer any questions if I can, and I'm sure more experienced members will add in if/where it is necessary (just like Dean did earlier). I'm pretty much still a beginner as well, and there are new experiences for me in each of my builds.

Had a bit in the shop after work today...

First off, an action photo for a change - nothing special in that, except if you look closely, you'll see some smoke coming off from the cut, as I'm pushing the lathe a bit to get some material removed quickly - this is on 20 thou in-feed and a good rate of cross-feed, so the water from the infrequently sprayed water soluble oil evaporates, and the oil left starts to smoke. I made a couple of cuts to get the end of the workpiece down to 24 mm for threading:




Why did I include this photo? Well, for the simple reason that working like this will heat up the workpiece, and it will expand in length due to the heat. It is important to stop after every couple of cuts like this when turning, and loosen the tailstock slightly and re-set it. If you don't do this, the workpiece lengthening could end up pushing your centers so hard into their tapers that you'll have a heck of a time to get them out, or even worse, you could end up damaging the lathe bearings.

As further machining on the 24mm section would entail threading - and as a result a future problem with workholding - I stopped, and transferred the arbor to the mill to mill spanner flats on the section between the taper and the section to be threaded:




(Aside - I've been "bugged" by a certain member about using the new mill vise :big: - so there! - it works great!; Thanks Wagner!)

Back to the lathe with the workpiece, and I turned down more of the end to 22.4mm, and added a parting cut to the same diameter. The turned down section is a cheat to easily see when I'm at the correct depth of cut when threading, and the parting groove is for thread run-out while threading. Lazy rotter that I am, I'm going to thread the arbor and boring head to 16TPI - thats pretty darn close to a 1.6mm pitch. Now, I know I have stated that I normally work in metric, but as this is a one-off, I'm taking liberties; it's easier to single-point thread in imperial with my lathe - I get to use the thread indicator instead of having to reverse it all the time to get back to the start :big:. This is where I stopped this evening:





I'll cut the thread when I'm feeling fresh and can finish it in one session; I love single-point threading, but it does take some attention ;D

Regards, Arnold


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## Wagner1975 (Aug 3, 2010)

Whoo hooo ..... I'm looking over your shoulder aswell .... can't get enough of this tooling business! :big:
Glad to see the vice being usefull .... still glad my little mill didn't topple over when I tried it out! :hDe: Fits nicely on your machine though! ;D

Regards
Wagner


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## arnoldb (Aug 5, 2010)

Thanks Wagner ;D - the vise appears to be the ideal size for me Thm:.

Well, I haven't been in the shop again, so no further progress. At least I managed to find another bit of 60mm x 250mm long BMS to use instead of the cast iron for the head today ;D

Regards, Arnold


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## njl (Aug 7, 2010)

Great thread Arnold, I'm enjoying watching your progress. I also have a boring head on the to do list.

Nick


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## arnoldb (Aug 7, 2010)

Thank you Nick 

At least I got a bit done today. Not much though, but at least some progress.

First off, turning the threads on the arbor. The last threads I turned on my lathe was for the rotary table chuck adapter - that was 12 TPI. So setting up the lathe change wheels for 16 TPI was easy; I just had to change one gear ;D. My lathe's leadscrew is 8 tpi, and I had a 40-idler-60 tooth set mounted for the 12 tpi; I just replaced the 40 tooth gear with a 30 tooth. The lathe's screwcutting chart specifies a 20-idler-40 set, but as long as the ratios are the same just about any combination can be used to give a 1:2 headstock to leadscrew reduction - as long as it fits on the banjo. I always use a strip of typing paper tightly rolled in between the gears to set the tooth clearance:




Oh yes, don't forget a drop of oil on the gear teeth and their bushes. I'm not sure if plastic gears need lubrication, but metal gear wheels do.

Setting up for threading - I'm going to cut 60 degree threads, so my 60 degree external thread cutting tip, and a guage plate to make sure it is set up squarely:





Then a light pass - just a thou (0.02mm) deep - turning the chuck by hand. I always do this check; sometimes there are surprises in store, and this was one of those times! :




If you look carefully, you'll see that the toolbit touches the shoulder on the left of the thread run-out groove. That shoulder is important in this specific arbor application, and must not be damaged - so I can't cut the thread with this toolbit.

 scratch.gif How now brown cow ? I dug through my toolbits, and found a bit that I ground quite a while ago for situations like these. The toolbit has a tiny 60 degree tip and when I ground it, it was exactly for the purpose of threading up to a shoulder. Here it is mounted and showing the clearance:




Just adequate - so no need to grind a new cutter ;D

As the first cut was very light, I set the tip to approximate the first test cut - and did another manual test - you can see the second groove from the second test:




When starting a thread, this is adequate - and no need to get it any closer. Picking up a part-way cut thread (for example when your cutting tips break while threading) requires much better accuracy and a good "feel" for your lathe though!

This is a relatively fine thread to cut - I did just three passes to get it down to "size", but something was looking wrong... When I did the last pass on what was supposed to be "size", the crests on the threads were still slightly flat, and not sharp as they should have been! I knew I used a 60 degree tip for cutting, so that was right. Some measurements, and I found that the section towards the tailstock that I thought I had turned down to the required 22.4mm (to cheat at finding thread depth) was in fact still 22.6 mm in diameter. So much for cheating :big: So I went back to the end of the stock, and dialed in another 4 thou (0.1mm ~= 4 thou) and did two passes at that setting - the first to "cut", and the second to "clean". This is what I ended up with:




By no means the best set of threads I have done, but in this case "it will do"

On to the band saw to get rid of the excess - with a bit of scrap to support the end as squarely as possible:





To finish off the threaded end, (I could just have left it as sawn off, but that's just not good enough) I chucked the arbor in the 3-jaw on the short piece of parallel section that I made at the end of the taper. If I was a reckless kind of person, I could just have faced the end off, but there was simply too much overhang. The fixed steady literally takes less than a minute to set up and support the overhang, so I did - and then faced off the end:




As you can see, the steady fingers slightly overlaps the spanner flats I milled in the arbor - thats not a big issue, as most of the fingers are carrying on a completely round bit of the arbor.

Facing a threaded section leaves a VERY sharp section of "half thread" at the start - I just used a needle file to file it down flat about 1/3rd of the way around. One thing I'm not entirely sure of is the treatment of this section of the start of a thread - there might be a better way to handle it.
The finished arbor:





Next up, a bit of steel to start on the "base" of the boring head:





I chucked that up and tried to face the yellow painted bit off, but promptly ruined the tip of my favorite HSS cutting bit on it. I tried a carbide tipped tool next, and while it cut it, there were some decidedly hard sections on there - it actually deflected the carbide tip tool visibly! - so there was a very hard section on that face. The face in question appears to be sheared, so it could be work hardened. Turning along the length of the piece, it became apparent that that was the case - the rest turned down nicely - so I sliced off the end on the band saw. If you look carefully, you'll see where I tried to machine the face and the hard section started by the ridge at 2 o' clock:





With that lot out of the way, it was a simple matter to mount in the lathe and true up the band sawed bit:





Then flipped in the chuck, center drilled to get tailstock support, and a 15mm wide step turned on. I didn't bother to measure the depth - just to "taste" :big: :





Then I drilled out the bit with a 4mm drill to 20mm deep, then a 10mm drill with the lathe at lowest non-backgear speed. For the 16mm drill in the next photo I changed to highest back gear speed:





That was followed by a 19mm drill, and I stopped for today:





Regards, Arnold


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## Deanofid (Aug 7, 2010)

> By no means the best set of threads I have done, but in this case "it will do"



Shoot, your threads look good to me, Arnold. The finished piece looks good, too!
The color on the large lump you turned down later in the post looks suspiciously like
Caterpillar Yellow. Maybe it was a big pin, and had been hammered on one end, making
it hard. 
You got it whipped, whatever it was.

Thanks for the new post,

Dean


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## SBWHART (Aug 8, 2010)

Coming along nicely Arnold. :bow:

Stew


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## FIXIT (Aug 8, 2010)

Turning down a little piece the root dia (if that's the right word) is a good idea,

As i can't cut threads on my machine and the biggest thread I've ever done is 6mm 
using a split die in the tail stock withe the die screwed fully open for the first pass it wouldn't be any hard ship to incorporate this as well as testing with a nut.

Thanks Arnold

Who said you cant teach a old dog new tricks.


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## arnoldb (Aug 8, 2010)

Thanks Dean  - Now that you mention it, id does look like Caterpillar yellow... But its not from a CAT - the engineering company where I got it buys full lengths of steel rod in this diameter; apparently they use quite a bit of it. The storeman there gave it to me for free when I bought some other stock ;D

Stew, Thank you 

Thanks Steve  A short section turned down to root diameter will also help a die to start nice and square and thus prevent a drunken thread.

Today's little bit...

I first bored out the hole to the 22.4mm root diameter I needed, and also squared up back face to remove the taper left from drilling:





(Sorry; fuzzy photo)

Next I needed a way to make a thread run-out groove in the hole as close as possible to the back face. No bits in my collection for that... So I started with this:




A bit of round 4mm HSS and a shank from an old carbide tipped tool.

I milled a 4mm slot into the end of the shank:





I needed a short section of the HSS so I cut part-way through at a suitable length with the dremel and a cutoff disc:




Then with a pair of pliers snapped off the bit. If you try this method for snapping off HSS, remember to wear your safety glasses! - the HSS breaks like glass ad bits can go flying.

Assembled and fluxed with a bit of silver brazing rod lying at the ready:





I used a butane torch to heat up the assembly just below the HSS bit. After the flux flowed and things got nice and cherry red, a dab with the silver braze stick and job done; took all of 30 seconds. All brazed up and cooling down:




I've found that HSS brazed up like this works just fine afterwards even though it was heated so high.

A quick trip to the bench grinder, and I had a parting side and a threading side oriented upside-down from each other but on the same center line. The threading side was also ground to be nice and square to the shank. I'm lazy  It's not a pretty tool though - but functional:









I then mounted the toolbit on the lathe, with the parting side facing the front of the lathe and on center height. With the lathe in middle back gear speed, I turned in the groove at the back; barely visible in this photo:





Next I turned the thread. I prefer to do internal threading with the threading tool upside down and on the back face of the workpiece. So no need to re-set the cutter or anything - the way I made it everything was already set up to do just that. As I told you, I'm lazy ;D:




As there was not a lot of space to stop before crashing the toolbit into the back of the workpiece, I settled on using the same number on the thread indicator for each pass. A manual test to take the reading on the leadscrew handle at the point of touch, and I had a reference for the threading passes; stopping each threading pass a couple of thou short as indicated on the leadscrew handle. 

Finished - and ready for some milling to commence:





And the arbor screws in very nicely; smoothly but with no play at all in the threads :





Thant's me done in the shop for a while; this coming week I have to attend to other matters in the evenings, so most likely I'll only carry on next Saturday.

Regards, Arnold


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## kvom (Aug 8, 2010)

Looks good. But I'm wondering why the arbor and head couldn't just be one piece rather than screwed together.


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## deere_x475guy (Aug 8, 2010)

Arnold, thanks for taking the time to post your build on this and nice job of the threading tool. :bow:


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## Deanofid (Aug 8, 2010)

> As I told you, I'm lazy  ;D



Not in my book, my friend. You're using the ol' noodle.
Besides, lazy people don't do this kind of stuff. 

Thanks for showing the cutter making process. I learn something every day, (if I'm
paying attention). You're way is a lot better than me trying to file a square hole in
a boring bar! I can see how it would easily work for square bits, too.

It's all looking good, Arnold!

Dean


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## arnoldb (Aug 9, 2010)

Thanks kvom  - One could make it as one piece, but there is quite a bit of milling work to do on the face, and having it as one piece would make for some awkward work-holding moments. And I'm a cheapskate as well; can't stand to see too much good metal turned to swarf unless its absolutely necessary 

Thanks very much Bob ;D

Dean, Thank you ;D; I'm glad you like the method; I can't recall where I got the idea from though.

Kind regards, Arnold


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## njl (Aug 9, 2010)

Hi Arnold, thanks for the info on how you did the internal threading, now I see how I should have done it! a light bulb on moment for me :idea:

I've only made one internal thread to date, a fine thread for an OS 91 FS aero engine exhaust extension. I used an upside down tool, ran the lathe backwards but rather than make an undercut first I just fired up the lathe wound in the full cut and then started the auto feed. On this ocassion it worked out fine but I knew the method was clunky.

I like your tooling too, means you can get the thread very close to the blind end of the hole.

BTW what RPM did you use to cut the thread.

Nick


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## Florian (Aug 9, 2010)

Hey Arnold

What about welding two pieces of raw material together ?   

Florian


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## arnoldb (Aug 9, 2010)

Thanks Nick ;D - Yes, if you can do a full cut in one go, there's nothing wrong with your way of doing it. And if you can run in reverse to get the tool coming out of the hole like you did, that's even easier. For deeper threads, you can use that very effectively if you make the undercut Thm: I don't do reverse cuts on my lathe, as the chucks screw on; it can be done but I'd prefer not to have a chuck unscrew while working. I quickly had to look up the speed; 62 RPM; not fast at all. If you search HMEM, Rick (Rake60) had a video somewhere where he demonstrated some threading - at speed!

Thanks for checking in Florian . Yes, raw material pieces could be welded (or brazed) together. In my next update you'll hopefully be able to see why it is easier to make the arbor and head base in two pieces. One could of course machine both pieces and then weld/braze together, but that could potentially lead to distortion or warping because of the heat, and could render the tool less-than-satisfactory. Another option (if you don't want to turn threads) would be to make both pieces - and where I turned the threads just make a light press fit, press both together, and then pin them together with a steel cross-pin. I wouldn't recommend doing that without the pinning nor by using grub (set) screws or Loctite - the boring head will be rotating in use - in many cases unbalanced - and it could be quite dangerous if it came off the arbor during use.

Kind regards, Arnold


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## arnoldb (Aug 14, 2010)

A bit of a quiet week in the shop...

Grabbed an hour or so today though. At least I had a luxury in the shop; my grandparents are visiting from the RSA, and my grandfather volunteered to be the "lubrication system" - standing to one side of the mill with the squirt bottle while I cranked the mill ;D

First, I milled two identical opposed flats on the threaded side of the base:





I remembered about the questions of making the arbor and base as one part - the next photo shows why it would be difficult to clamp the workpiece and mill on the face:





With the base clamped on the flats I milled earlier, I did a quick check on both X and Y to check that it was sitting flat using a DTI:





Then I started milling out the center of the piece with a 14mm end mill - with Gramps operating the squeeze bottle and a brush to brush chips away. There was a brown-pants moment when the cutter dug in (not the cutter's fault - mine; greedy pig that I am!) and pulled slightly from the collet. Fortunately, it also slipped in the collet then, and I was able to hit the stop without any damage except for an unsightly mark at the one end of the slot. Fortunately that will still be removed when finishing and I was able to pick up all the necessary measurements to continue:





I called it a day there; I doubt if there will be much updates in the coming days, as I'm spending some quality time with my family.

Regards, Arnold


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## Deanofid (Aug 14, 2010)

More progress is always good, Arnold!

Enjoy your time with the family.
Is your helper grandpa named Fred, as in "Fred the Locomotive" fame?
 ;D

Dean


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## arnoldb (Aug 15, 2010)

Thanks Dean ;D - Yes, I have the privilege of enjoying time with grandpa Fred and granny Veronica ;D (No guesses as to my second-to-build locomotive's name!)

Kind regards, Arnold


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## zeeprogrammer (Aug 15, 2010)

arnoldb  said:
			
		

> (No guesses as to my second-to-build locomotive's name!)



Aha! A second-to-build locomotive! When!? What kind? What size? Tell me, tell me.


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## arnoldb (Aug 15, 2010)

:big: - Patience is a virtue Carl  I have some other things to finish first!
I'll let on that it will be O gauge, and a foray into the tricky world of designing my own though...


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## arnoldb (Aug 21, 2010)

I managed a bit of time in the shop today 

First off, I needed a way to cut the dovetail on the head. I priced some dovetail cutters locally here in Windhoek, and after recovering from the ridiculous prices wanted, I had an option - order from overseas for 1/5th of the price (and wait 6 weeks for delivery) or make my own.

It was worth a try to make my own - so I thought a bit. I could have gone for HSS and spent a lot of time trying to grind an accurate cutter... OR - I could get back to basics and do it the really old fashioned way - with silver steel. I've made a fair lot of silver steel (drill rod) bits and cutters, but have never tried to use them on steel; well, there's a first time for everything.

My biggest piece of silver steel rod is 20mm in diameter; slightly too small to make a cutter as-is, but I had a plan. This is what I started with:





I mounted the rod in the 4-jaw, and offset it so that I could get a shaft diameter of 12mm with an 8mm "lobe" projecting when turned down a bit:





With the tailstock set over to 30 degrees (I decided on a 60 degree dovetail), I turned the lot down. Here, its part-way; you can see the lobe forming:





Once the shank part got down to 12mm, I finished off the taper on the lobe as smoothly as I could, and also turned a light undercut towards the center of the face on the end - this is for chip clearance at the bottom when in use.
Then I removed the lot from the lathe - chuck-and-all, and mounted it on the rotary table on the mill and whittled away half the lobe to get the cutter form done:





Removed from the chuck, I sawed the eccentric part that was gripped in the chuck off, then heated the cutting bit red-hot and quenched in oil to harden up the bit. A test with a file showed the shank part not completely hardened, but the cutting face was good and hard, so I had a very hard cutting edge and a slightly softer core on the bit. Because of this, I decided not to temper it - I just used a couple of strokes on an oilstone to hone up the cutting edges. This is what the cutter turned out like:




Poor photo; the light gray parts on the cutter was actually shiny from the honing. The light gray rectangle on the bottom is where I stoned in the bottom relief, and the light gray on the face is honed for the cutting edges.

Would it work ??? - the first cut; slow speed (150RPM), slow feed, and LOTS of cutting oil - and the first pass was done - and seemed to work well:





I'm a fan of Asterix... - in the books the authors (translators actually for the English books) always say "A little while later" for a journey that would have taken days (or weeks)... - but in my case, "A little while later" - in hours:




It was slow going; I didn't want to push the cutting bit too hard (heat is enemy #1 to silver steel!), and spent a lot of time squirting coolant on it. But it cut ;D - the dovetail itself has a very near mirror finish, though I'm a bit disappointed with the bottom finish I got; it could have been a lot smoother.
Overall, I'm happy though ;D - I had some time in the shop, made a single-point dovetail cutter from scratch, and cut my very first dovetail (at least part thereof!) on the mill. A good day ;D

Regards, Arnold


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## SAM in LA (Aug 21, 2010)

Arnold,

I really like how you think outside the box with the solutions you come up with.

I would have never thought to make 1/2 of a dovetail cutter.

I learn something new each day.

SAM


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## SBWHART (Aug 21, 2010)

Thats a great job Arnold

The cutter has done the job really well.

Stew


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## Deanofid (Aug 21, 2010)

Again I'm amazed the ingenuity of some of the people here. Quite a successful day, Arnold!
The lack of tooling, or their high cost in your area, is turning you in to quite a tool maker. What
some of us would call a major inconvenience, you make into a learning exercise, and are becoming
a hard thinking machinist in the bargain.
Well done!

Dean


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## Lew Hartswick (Aug 22, 2010)

I did something like that a few years ago when I needed a special angle for a brass
fitting for an antique transit. I had the advantage of working in brass and so didn't
even harden the cutter. 
  ...lew...


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## arnoldb (Aug 22, 2010)

Thanks Sam  - There's not much "outside of the box" though; just applying (or at least trying to apply) some basic machining practices that was in use well over a century ago already - and that somehow seems to be receding into the mists of time.

Stew, Thanks very much mate 

Dean, thank you very much ;D Fortunately I'm not an easy fellow to get down if I've set my mind on something - so I do what's needed to get the job done. Instead of moaning and groaning about some extra work to get to the final goal, I simply choose to make it worthwhile and get more fun and experience from the process. From my limited experience, I think at least half of getting a job done successfully is accomplished just by taking a positive attitude  Maybe I'm lucky to have more limited access to all the doo-dads thats available at the drop of a brown package in a short time overseas ;D

Lew, thanks for checking in  - yes, a quick un-hardened once-off cutter for brass would work 

Kind regards, Arnold


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## njl (Aug 24, 2010)

Great job Arnold, I'm really enjoying your approach to getting the job done and I'm learning loads of useful stuff from you, thanks for sharing. I've not tried heat treating to harden metal yet, got the workshop series book on it though, so will definitely give it a try in the not to distant future.

Nick


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## Blogwitch (Aug 24, 2010)

Arnold,

Sorry I haven't commented before.

This is becoming a great post, and you really are coming along very nicely seeing as you had very little experience such a short while ago.

I didn't just comment here to pick you up on a machining oversight, but I will give you a little tip.

When you are machining a fairly large piece as you have been doing, especially round, it is always better if you can machine in the Y axis rather than the X. The material is better supported by the vice jaws in that direction, and won't be tempted to to be knocked over sideways.

Bogs


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## arnoldb (Aug 24, 2010)

Thanks Nick  - it's a pleasure to share! 

Bogs, Thank you  - Your tips are always welcome and very much appreciated, not only by myself, but I'm sure also for anybody else who choose to use them! I'll definitely give the Y-machining direction a go when I do the other part of the boring head and report back 

We have a public holiday here in Namibia on Thursday, and I have put in leave for Friday to make a long weekend, so I'm looking forward to a good bit of shop time then 

Kind regards, Arnold


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## zeeprogrammer (Aug 24, 2010)

You and your threads are always a motivator for me Arnold.
Thanks.


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## arnoldb (Aug 26, 2010)

Thank you Carl ;D - that makes posting really worthwhile for me!

Today's bit; the boring head base is pretty much finished now.

To mill the slot in the base where the leadscrew and nut will run in, I first drilled out a lot of the excess:






Then milled it out to 10mm; my 10mm slot mill is VERY blunt; it's time to get a new one or build a tool grinder...:





Next I cleaned everything up with a 4mm multi-flute end mill - this one's nice and sharp, so things went really well:





To drill the hole for the leadscrew, I used a small square to set the part up in the vise:





Then I drilled and counter bored the hole as required:





To set the part up to drill the holes for the gib screws and lock screw, I used a thin plate to set it horizontal:





At this point I paused a bit and thought about the future use of the boring head,as well as the sizes and function of the gib screws and locking screw.
Steve's plans call for the gib screws to screw into the gib itself, with clearance holes through the body of the head. Dean made his boring head with threads both in the gib and the boring head. I decided to rather go for threads just in the body, and locating holes in the gib - a more conventional layout. I'll use longish 4mm grub screws (set screws) with a bit of medium strength thread retainer on the threads to prevent them vibrating loose. I was tempted to use screws with lock nuts, but space is at a bit of a premium so I decided against that. 
I already have a good idea of how I want to make the leadscrew, and that would entail a modified M5 socket head cap screw for doing the adjusting. This is where thinking of the boring head in-use comes in - ideally, I'd like to use only one size of allen key when in operation, so that means the locking screw must also be an M5 socket head cap screw. One problem though... an M5 SHCS's head is about 9mm in diameter, and I only had 8mm to work with, unless I offset the lock screw. That wouldn't look nice though. There is quite a bit of meat on a 5mm SHCS head, so I decided that I could take one and turn it down enough to fit the 8mm I had available.

In the next photo, I'd finished drilling one gib screw hole to 3.3mm (M4 tapping size), as well as the 4.2mm tapping drill and counter bore for the locking screw, and I'm getting ready to start on the second gib screw hole with the largest center drill that would work to start the hole on the angle caused by the rounding on the workpiece:





Then I threaded all the holes, and turned the head down on an M5 SHCS to fit the lock hole; the screw still needs to be shortened, but I'll do that at a later stage. This is where I stopped for today:





Regards, Arnold


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## Deanofid (Aug 26, 2010)

Looking good, Arnold.  Thm:
Thanks for the new pics and words!

Dean


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## arnoldb (Aug 27, 2010)

Thanks Dean ;D

Today's little bit... I started work on the sliding part of the head - first off, some mild steel crudely cleaned up to get it nice and square after bandsawing:




I'll bling it up later, as there is still quite a bit of work to do on it.

Then I diverted a bit from the boring head, to make a small pair of matched V-Blocks. There have been many occasions where I needed a V blocks but I never got around to getting/making some. I could have made just one, but a matched pair can be very usable in some set-ups, and it's easy to make. Though not precision ground and all of that, these should help me in a lot of cases:





One of the V blocks was put to use immediately - to hold the workpiece in the mill vise. Two 50mm bearing outer races acts as parallels, and I tried Bogs' tip of milling on the Y axis feed. Worked a treat and I could take a 3mm deep cut with the 14mm mill in one pass. The milling machine didn't complain at all - just took some good sized chips off the workpiece at a good rate of feed ;D:





Both sides milled off the workpiece:





Flipped in the vise, and milled down to cut the dovetails:





I stopped today with one side of the dovetail cut. The cutter barely made it, and is in dire need of some honing - I'll do that tomorrow and finish the dovetail.
A view of where I stopped - in the photo things look like it's not a good match, but that is mostly an illusion caused by generously chamfered edges and some pretty bad clean-up filing on edges on my part :big: - rubbing the two pieces together on the partly-formed dovetail, they slide together much better than I anticipated!:





I had a dash around town this morning to get some supplies - and one thing I forgot was an 8 or 10 mm ball nose mill... Guess I'll have to annoy the engineering supplier tomorrow morning again!

Regards, Arnold


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## Deanofid (Aug 27, 2010)

Things are getting pretty nicely matched up, Arnold. I think you got pretty fair life out of 
your shop made dovetail cutter, too. Drill rod seems to take a bit of a beating on an 
interrupted cut. Some stone work, and one more cut! It's going well!

Dean


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## arnoldb (Aug 28, 2010)

Thanks Dean - yes; the cuter barely made it, but it was an interesting experience - and its handy to know I can make my own cutters should the need arise  . I think I'll order some dovetail cutters from overseas for future projects though...

Things went well today; after I sharpened up the cutter, I finished the last dovetail cut:





Then I milled the pocket where the leadscrew nut will engage:




To get rid of chips from the pocket while milling, I just held the shop vac nozzle to suck up the chips. I wasn't going hell for leather on the cuts, so the chips were cool and could just be sucked up.

On to the gib. I'd miscalculated the size of brass needed for the gib, and the bit in the first photo of this thread was too thin. So I scratched around my stock to find something suitable that would not waste too much material, and settled on some 8mm hex bar to use. This was a blessing in disguise, as the hex bar shape would help when cutting the 60 degree angle needed on the gib ;D
I first milled a flat out of the bar, keeping two "blobs" on the ends:





Then with the brass bar supported on makeshift parallels and with flat ends toward the bottom of the mill vise, I could mill out the angled part of the gib:




I did say "makeshift" - the two V-blocks I made yesterday makes up part of the parallel, and there's an 8mm square HSS toolbit between them and the workpiece!

This is what the gib looked like after milling:





With the "blobs" sawed off and installed on the rest of the bits:




I couldn't test the size of the gib properly after milling - those "blobs" were in the way, and it was _just_ too large initially, so I brought out the trusty files and filed it down to fit closely.

Then I marked spots on the gib for the retaining screws an lock screw by twirling drills through the various screw-holes in the body, and lightly counter drilled the spots in the drill press; that pretty much finished the gib:





Things needed a triming down and tidying up, so I locked the slide of the head on the body with all of the screws, and mounted the lot on the lathe to turn down:




It was nice to get back to the lathe for a change after all the milling I've been doing for the last couple of days ;D

A little while later after some turning and a bit of elbow grease with strips of oiled emery:





For the tool mounting holes, I started off drilling the holes. I got bored while drilling, so played a bit of "stack the drill swarf" in the process. The swarf lying on the cross slide landed there while drilling - I didn't touch anything!:




That was a 7mm drill - it was followed by an 11.5mm drill, and then a boring bit to open up the hole to 12mm.

Like Dean, I decided on also making just two tool holder holed in the boring head. So with the head offset and locked into place, I prepared for the second hole. That makes a big lump of metal hang off-balance on the lathe, and I had some trepidations... First off, I reduced spindle speed, checked for adequate clearance all-round, and then popped the clutch on the lathe - the old girl did not complain at all, and I could detect no untoward vibration, so things were a go for the next hole:





After drilling and boring the second hole, I decided to call it a day, and here's what things looked like when I stopped:




I think I'm about half-way there ;D

Regards, Arnold


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## Deanofid (Aug 28, 2010)

That looks terrific, Arnold.
I think my favorite part of making one of these was when I got to put both pieces
together and turn down the finished diameter on the OD of the assembled boring head.
It just seemed like the whole thing came together at that point. 
It's a really good project, and you're doing great!

Dean


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## arnoldb (Aug 29, 2010)

Thanks Dean ;D - Yes, I'd have to agree with you - putting those pieces together to turn the whole lot down was a serious feel-good moment!

Well, not much done today... Life got in the way of shop time.

First off, drilled the tap size holes for the tool retaining screws:





Then milled the side flanges down more and left adequate meat for running through with a ball nose mill. The extra step I milled out was to make the job for the ball nose mill easier; I'd never used one before, and didn't know what to expect:





On to the ball nose mill; On the first side, I took several light cuts to get down to size, but the mill wanted a very slow feed, so it took a lot of time... I was more bold on the second side, and took the full cut in one go; this worked surprisingly well; I could run at the same feedrate as for the smaller cuts and it took only one pass!





Next up was the feed nut; it was relatively quick to make. First I milled a block of brass to size, then drilled and threaded it to accept the leadscrew. I recently invested in some quality M6x0.5mm taps; they were expensive, but I will find a lot of use for them in making steam fittings in future, so worth the investment. I used the mill spindle to start the tap properly in the hole, and then finished tapping by hand:





The feed nut needs a chamfer on one side to allow one to assemble the boring head - I just ran a countersink past it a couple of times to get the chamfer:





The finished nut:





I really wanted to have the boring head finished this weekend, but alas - not to be, so the rest will remain for next weekend - unless I find some time after work during the week.

Regards, Arnold


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## walnotr (Aug 29, 2010)

It is quite the treat to see so many familiar parts on familiar drawings! You are doing a great job Arnold.  :bow:

Steve C.


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## Deanofid (Aug 29, 2010)

walnotr  said:
			
		

> ... see so many familiar parts on familiar drawings!
> Steve C.



 :big: :big: :big: 
That's funny, Steve.

Again, looking all good and proper, Arnold. Funny about the brass 'nut'. I went by Steve's print
for mine, but couldn't figure out why the heck he had make that odd sloped side on it. That is, 
until I went to put it all together!

Dean


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## arnoldb (Aug 30, 2010)

Thanks Steve ;D - Kudos to you though; a great set of plans do make thinks a LOT easier :bow: No catches, I took your measurements, converted them to metric and scaled up, and it just works!

Thanks Dean ;D - I forgot to mention I had a "blonde" moment testing the fit of the nut as well :-[ - I knew why the sloped side was needed, and put it on the nut, but couldn't get the thing together... Turned out, the last time I disassembled the lot, I just slid it apart and let the gib drop out - but I never unscrewed the gib screws to get clearance to make things go together; I spent nearly ten minutes trying to figure out why before I realised :big: :big: 

Kind regards, Arnold


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## Florian (Aug 31, 2010)

Hey Arnold

That boring head looks really good. 
But i am thinking about one detail for a while now:
Why do you use an incomplete dovetail on one side?
Im not shure about it but i would say the rigidity of the boring head is somehow reduced because on the "square side" (well, the side with the "half" dovetail) the under part of the head can just move downwards with, well, relatively small effort, especially if there is a little play (and if its only just to adjust the boring diameter). 
Of course you will tighten it when boring (and after adjusting) But even

I think you also have to think on the fact that the material itself is not absolutely rigid and the head could give in slightly (in the elastic range) and this would really promote chattering. 
I guess that is the reason why all the commercial ones have complete dovetails on both side. Because then the under part of the boring head then is well defined in contrary to the solution with one incomplete dovetail on one side... 

Maybe its no problem, i can't say it but finally i just wonder why you decided to make an incomplete dovetail on one side...  

Anyway, i would always use the boring head that way around that the load points away from complete dovetail. Why? Because then the possible Play on the "flat side" is being eliminated and the under head may buckle a little and the complete dovetail is being pulled downwards because of buckling and so the play is being eliminated by this. If You put the "load" to the other direction, the under part will be pressed against the upper part on the "complete" dovetail and buckling will be promoted because of the lack of the complete dovetail guide on the oder side (the gib will be able to "slide" down). 

Florian


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## arnoldb (Aug 31, 2010)

Thanks Florian ;D - I must admit you raised a good point! - I didn't think that far ahead :-[

From the design though, things should lock up adequately for rigidity from my point of view. The "half dovetail" section and it's adjustment and locking screws would be subject to pretty much the same forces as applied to a full dovetail. The entire lock-down force still gets carried by the lock-down screw at the end of the day - I think!

I'm not sure how the up-sizing would affect the boring head - I guess I'll find out in due course. Neither Steve C nor Dean has mentioned any problems while machining with this boring head as-designed - I guess I'll have to just wait and see how it performs scaled up 

Kind regards, Arnold


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## arnoldb (Sep 4, 2010)

Finally - the boring head is done ;D Quite a big update, so my apologies if things are a bit slow to load in your browser!

The leadscrew needed making... Steve and Dean used modified cap screws; a perfectly good solution. I didn't as I wanted a 0.5mm pitch lead screw, and M6x0.5 cap screws are unobtainable locally, so I had to do a bit more work than really necessary.
I started off with a bit of 6mm silver steel in the collet chuck on the lathe and parted a 4mm wide groove in it to 4mm diameter. This groove becomes both thread run-out, as well as the groove that the retainer slips into to keep thinks in place when the boring head is assembled, so it was carefully marked off at the appropriate length along the workpiece:





On to threading; I have single-point turned a couple of threads in the last 2 years, but this one was new territory for me. It is by far the finest I have attempted, and there would be definite flex in the workpiece. To make sure I had no unexpected surprises from the drivetrain, I cleaned all the change gears and the lathe's lead screw much more meticulously than I usually do - not that I'm not meticulous with this part normally - today I was just about anal about it. I also dug out the traveling steady I made as one of my earliest projects for the lathe. Last, but by no means least, I spent quite a while honing my HSS threading tool to as sharp a point as it ever had; on this fine thread, only the last 0.25mm (10 thou) of the tip will be used, but the cutting angle must be accurate and sharp there. This is the setup - ready for threading:





Seeing as this thread was for metric, I had to keep the feed nuts engaged and reverse the lathe after each cut, so I wasn't too keen on taking that many passes... First cut was at 7 thou infeed with lots of cutting fluid, then another 3 thou added, and run through again at the same setting to clean up a bit. This is the result at that point:




I was concerned that it looked a bit rough at this point, but a quick run-past with a small wire brush cleaned of the gunk, and the feed nut screwed on easily but without any play or roughness ;D

Then I sawed of the leadscrew-in-making 10mm beyond the parting cut and chucked it in the collet chuck with the sawn-off face pointing out. This was faced off, and drilled and tapped for M4:





An M5 cap screw was then chucked by its "cap" in the collet chuck with the thread sticking out. I turned down the threaded section to 4mm, and re-threaded it to M4:




Some excess length was then sawn off.

The above was a lot of boo-hah just to get to this point:





Next the leadscrew was chucked up in the collet chuck once again and the cap screw thoroughly and forcefully screwed into the leadscrew, effectively completely seizing it up thoroughly. Then I turned the head down to 8mm OD for a distance of 3mm:





Some 3mm brass plate was marked up:





Then sawn off, and drilled with an 8mm hole in the center. From some previous "Fun", I know that my 8mm drill will drill a slightly triangular hole in thin brass plate, and I used that to my advantage in this case. The hole actually ends up JUST below 8mm nominal diameter, so becomes a light press fit on an 8mm round section - I used the tailstock holder which happened to still be sitting in the tailstock to just press the piece of plate over the head of the cap screw:





Then I took the workpiece, clamped it in a toolmaker's vise in the big vise, and silver brazed the plate to the cap screw:




( :-[ Sorry - photo out of focus)

A bit of cleanup in the collet chuck later:





I love the new mill vise; instead of the elaborate setup I needed for making graduations when I built the rotary table, I could just clamp the cross-slide extension I made for the lathe in the vise and mount the dividing head on it:





A simple run-through with the same tool I made for graduating the rotary table, and I had 10 large graduations on the dial:





This was followed by 50 shorter markings. Initially I thought about 100 marks, but 50 is plenty close enough and gives me 0.01mm feed on the leadscrew per mark (0.02mm diameter increment). I can still "guestimate" settings between marks, so this should be plenty accurate enough for my needs:




(I rubbed a dirty oily finger over the marks to make them stand out a bit)

Next up, boring a recess for the dial in the B/H body... This was not a simple task, and it would have been nice to have a boring head to do the job :
Dean did this step on his rotary table, but I could not figure out a way to reliably clamp the boring head to my RT, as its a bit small compared to the B/H... So I ended up on the lathe, with the 4-jaw, and a piece of 6mm silver steel to align things and keep the operation safe. I used the dual-headed turning tool I made earlier in this thread for the boring. A couple of drops of oil on the silver steel held in the tailstock chuck, and pushed ALL the way through and engaging the back end of the B/H where the lead screw would end in, and things were moderately safe and aligned for turning:





Tolerances would be close, so instead of risking smashing the boring head body into the toolpost, I used two layers of masking tape to provide for warning; if the tape got caught, limits would be very close indeed!:





With the lathe at high back-gear speed, I bored out the recess - very gently. This setup was not very rigid, so I erred on the side of caution and safety. After boring out the recess, I used my normal cutting tool make the scale reference mark on the body - a couple of quick traverses with the cross-slide (one too many in fact), and the mark was there (on the body just to the top right of the cutting tool tip in the photo):




One too any, as the mark ended up a bit deep for my personal preference...

Next up, the lead screw retainer - all marked up on some stock:





 :-[ I thought I'd taken a photo of the retainer as-finished, but I didn't! I milled it to size and filed roundings on the outside edges, and it slipped in in position. I was a bit over-vigorous on the rounding over though!:





Then I assembled everything, and ran into a minor snag... My 12mm draw bar is a Weeee bit long :-[. I don't have a sufficient length of 12mm threaded rod left for making a new draw bar, so some shopping required after the weekend to make a new one for the boring head:





Besides the draw bar issue, the B/H is completed though not tested ;D:









By no means a perfect job, but I'll settle for this. Operational testing will have to wait till I get a length of all-thread to make a draw bar for it, but I just think it may work ;D
All-in-all, it appears to work as intended; I have very little backlash on adjusting the head, and all adjustments are nice and smooth, so I'll call this one finished.

This was an immensely enjoyable little project with it's own set of challenges and first-for-me operations. ;D

Special thanks go to Steve C and Dean - for sharing so unreservedly from your own experience!

Thank you also to all who followed along and especially those who contributed to this little quest :bow:

Kind regards, Arnold


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## ozzie46 (Sep 4, 2010)

Well done as usual Arnold. Both project and postings. Thm: Thm: Thm:

  Ron


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## Deanofid (Sep 4, 2010)

arnoldb  said:
			
		

> By no means a perfect job, but I'll settle for this.



Wow, I would not feel like I was settling for anything with this tool, Arnold. 
It looks smashingly good! I'll bet you are really going to enjoy having one, and when
someone is over to your humble shop, and asks where you bought that boring head,
they're not going to believe you when you tell them.

Really Well Done!!

Dean


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## FIXIT (Sep 4, 2010)

brilliant STUFF 
 thanks Arnold i have been quietly 'looking over your shoulder' as before and learnt a lot, I'm going to have a go at making a dovetail cutter you make it look so easy !
and hope to raise my self to your quality of work.
so thanks once again

Steve :bow:


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## dsquire (Sep 4, 2010)

Arnold

Congratulations on 2 fronts. One is the fact that your last post was #1000. The other is the fantastic job you did making the boring head. I can still remember a bit over a year ago when you were new to the board and asking questions. From the looks of the skills that you have shown since then you were paying attention to all of the answers.

You have came a long way since you started on the forum and should feel very proud of your accomplishments. :bow: :bow: :bow: 

Cheers 

Don


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## arnoldb (Sep 5, 2010)

Thanks Ron ;D

Dean, thank you very much  I'll have to tidy AMESS at some point and post some "not-for-sale" signs :big:

Thanks Steve - go for it. Things get easier the more one work at it - it just takes a little effort . One lesson that I have learned is that "quality of work" is very much a matter of setting personal goals and aspiring to them - then things soon start looking like other people's good work.

Thank you Don ;D - I didn't even notice the post number ! Yes, I have been paying attention to the wisdom provided by the different members of HMEM - and its nice to slowly be able to actually start providing answers to similar questions that I asked when I started. I still have many questions and lots to learn though...
I am happy with my progress - and the best of it is it is really nice to get into the shop and look around at the assortment of tools I have made; my little collection has actually grown nicely from the bare essentials I started off with. There's a lot of time invested in the collection, but the return in experience and usefulness is beyond measure!

Kind regards, Arnold


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## Maryak (Sep 14, 2010)

Damn - I've been following along and missed the finale.............away with the fairies or another senior moment, (AGAIN )

Having got that under the belt,


*CONGRATULATIONS Arnold..........or in the vernacular............ BLOODY BEWDY*

Best Regards
Bob


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## minerva (Sep 14, 2010)

I'll second that Bob :bow: :bow: :bow:,
Super job Arnold. 
I hope to be back in the shop later today after a month out and I've promised myself the next project on my list is a boring head!
One query tho. Is it essential to have a Morse taper fitting or is it sufficient to use a parallel spigot for use with a collet?


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## Artie (Sep 14, 2010)

Arnold Arnold Arnold......what a write up! What a result!

Funny, being part of this electronic community makes ME feel proud of YOUR achievements..weird....

I LOVE my boring head... ID love it more had I built it..... yours looks like it came from the same factory as mine....no, wait....yours looks better....

Way to go mate....


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## kustomkb (Sep 14, 2010)

Awesome job Arnold!

People wonder why build a tool when one can be bought relatively inexpensively. Well you've shown exactly why it should be built yourself, and that tool would not be cheap. Watch out Narex!


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## arnoldb (Sep 14, 2010)

;D Thanks very much indeed Bob. Don't worry, those "moments" catch all of us 

Thank you Terry ;D. The morse taper is not required - a straight shank should do just fine, but use the biggest size you can for your collet set. I went the taper route as I felt it would be more rigid than running in my collet chuck with my B/H being on the large side and the maximum collet size for my mill being just 16mm. Not using the collet chuck saves a bit of headroom as well; about 70mm on my setup - which could turn out to be convenient to have at some future point. Of course, it depends on what you have; if one's mill has an R8 spindle, then one would go for an R8 arbor. There is an additional advantage to making the arbor a screw-in part like I did; its easy to make different arbors for the head - for example I can make an MT2 arbor for mine to use it in my lathe's headstock, or even the lathe tailstock with a center point to do taper turning. Good luck with your build Thm: - remember we like pictures ;D

Rob, thanks mate ;D. Drat - same factory ? - those Chinese get in everywhere... :big:

Thanks Kevin ;D. And thanks again ; my home-built tools just "feel" better to use than bought ones and that's as good a reason as any to build one's own tools. Besides, being in my corner of the world, it is actually cheaper to build my own. The cost of materials, additional cutters and consumables for this build came to about N$ 450 (US$ 56), and a "cheap 'n cheerful import" costs N$ 960 (US$ 120). The same went for my rotary table - cost as built N$ 700 (US$ 88) and to buy one locally N$ 4800 (US$ 600) . I'll look up that Narex crowd and slobber a bit :big:

Kind regards, Arnold


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## bearcar1 (Sep 14, 2010)

WOW! and DOUBLE WOW!! Man I fell asleep at the switch on this one. I don't know how I ended up missing all the excitement but that BH is a real beauty indeed. I take my hat off to you Arnold, you do some nice work and you make it look so darned easy. Thanks for sharing, I've always enjoyed seeing your setups. I've still to have the opportunity to do radiant graduation markings but will follow your lead when the time arises.

BRAVO!! Thm:

BC1
Jim


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## tel (Sep 14, 2010)

Ah,_ there_ you are Arnold. I was beginning to think you'd got et by a lion. Seriously mate, that is a brilliant bit of work - something you can be proud of.


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## zeeprogrammer (Sep 14, 2010)

Another awesome, beautifully crafted, exceptionally made tool under your belt.
Like I said before, you're an inspiration to people interested in making their own tools.
Very very nice Arnold.
Congratulations.


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## arnoldb (Sep 15, 2010)

Thanks Jim ;D I'm practicing those graduations - I will need every ounce I learned when I get around to making a tool & cutter grinder...

Tel, thank you; fortunately lions don't eat just any old thing ;D

Thanks Carl ;D - Get your lathe sorted & turn up those die holders; it would be an ideal test 

I'll be a bit quiet on the toolmaking front for a while; I've got a new engine project in design, and it will require some "peripheral" projects to test ideas 

Kind regards, Arnold


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## minerva (Sep 15, 2010)

Arnold
many thanks for your thoughts. The versatility of the threaded arbor with taper to suit mill/lathe is a valid one and on reflection I think I might re-arrange my project schedule and make a taper turning attachment. I have a couple of designs squirreled away some where and I think this may be the way to go!
kindest regards,
terry


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## arnoldb (Sep 26, 2010)

Its a pleasure Terry 

I finally got around to using the boring head for the first time today...
Not on one of the best metals to be found though; Copper is always a bit of a bugger, and the carbide bits I have for the boring head is not entirely suitable for copper, but it worked a treat ;D:
[ame]http://www.youtube.com/watch?v=LXmoImwLMiw[/ame]

Regards, Arnold


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## zeeprogrammer (Sep 26, 2010)

Very cool Arnold.
Was that actual speed?


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## arnoldb (Sep 26, 2010)

Thanks Carl  - yes, that was actual speed; I'm not sure about the speeds to run the boring head at, so started fairly slowly, but it seemed to work well at that speed. Can't recall what the exact speed is though; would have to open shop and look at the mill's speed plate to see...


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## Deanofid (Sep 26, 2010)

Hey, it cuts great, Arnold! Naturally. 

I have to make a wild guess; Are you making some kind of flue boiler there? 

Dean


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## arnoldb (Sep 27, 2010)

Thanks Dean 

Your wild guess is spot-on - a smallish experimental horizontal flue boiler. I'm not doing a build log on it though; being experimental that might not be a good idea. Once finished and thoroughly tested, I'll post on it - if it's up to scratch that is.

Kind regards, Arnold


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