My Lathe project; might CNC it one day

[Stevie]

Here is the cross slide set-up; the Bronze handwheel was todays effort; the alumi support was also made today (tool post is beside the cross slide)
The circle you can see is the referance locator for the compound slide; it keeps it on center as you swing the compound through the arc; an 8mm screw locks the compound


Looking right down the cross slides center; the small setscrew deep down is the adjustment for backlash; there is a small teflon button under the screw; it presses the leadscrew into the nut to reduce the backlash; the other 2 cap head screws hold the nut under for the leadscrew


Compound slide being attached; the 6mm allen key is in the locking 8mm caphead


Here is a bottom shot of the compound; the locating ring can be seen; the 2 small holes in the alumi handle extention are for gaining access to the locking 6x32 setscrews that lock the handwheel and the leadscrew adjuster


The compound on the cross slide; the allen key has locked the compound at an angle to show how tapers can be cut; the bronze insert in the middle is the nut for the 1/4"x20 leadscrew (0.05"/rev)


The final normal setting for the compound slide; the access hole for the taper setting is now closed as it's quite far ahead of this position; also helps to keep crap out of the allen head; tool post is on; the round guide bars for the main way are visible too; these are Thompson shafting; held with 4mm capheads into a CNC machined 90dgr each side of the main bed; these are accurate to within 0.001


Shot of the collet set-up; also in the shot is the main leadscrew bearing (just under the collet chuck) this will support the 7/16"x20 (0.05/rev) leadscrew
The collet chuck still need 2 holes drilled into it for tightening; the adjusters for the main carrage can be seen too with locking nuts; these again like the leadscrews have teflon buttons to help maintain accuracy; the cross slide has smaller set screws for the same reason (2 small holes just above the main section of the carrage)


Drive end of the spindle; the 1.125 dia is threaded ready to hold the 8 step pulley; the main bearing can be seen; another is right behind the collet chuck; the spindle can take 0.650" through; the run out is 0.0004" at this time; once the drive is complete I'll grind it totally true with a pencil grinder in the tool post

I'm also going to add chinese scales and make the ShumaTech DRO; there will be a tail stock added and a 90dgr block to make the compound into a vertical slide; the tool post will be removed and a small vice added to hold small parts
Top speed wil be over 12,000 and lowest speed will be just over 1400 with 8 steps
One day (after my NC mill) I'll CNC it

I should add; the project was designed in SurfCam 2001; the machines used to make the parts were a Supermax 56 and a Fanuc wire
I don't work at that place anymore (projects like this are not allowed; and I had to hide it all the time); my new place the boss says "hey just build whatever you want" (in my time) The Mill project is coming nicely in SurfCam 2002 and I'll post a photo of the shaded surfaces soon

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[Bloy2004]

Hey!
Very nice pictorial of your excellent work!

[Ken_Shea]

Very nice pictorial of your excellent work!

Bloy2004 does some really nice work and knows what nice work is, so that is a nice compliment to which I fully agree.

Nice work on the knurling, speaking of which I will post a question on in the correct forum.

Ken

[DDM]

Wow I must say that I'm very impressed. Its nice to work in a shop that will let you do your own projects in your spare time. Keep up the good work and post us on future progress.

Carl

[pack rat]

It really is Superb workmanship and plan. Great pictorial representation to boot. Talent is easy to recognized in the work it does and as a novice I can see it here.

[pminmo]

Stevie,
The round ways are interesting, did you build the ways or is it a part of an existing machine?

[Stevie]

Hi Guys; thanks for the kind words (although some of the parts I'm "Embarrassed" about; could have made them better; I rushed them to get them out of sight again)

pminmo: no it's not part of anything else; I designed it to be that way; the cuts are 0.250" X 0.250" the round stock is 0.500" the Supermax cut the rabbits and I simply screwed the stock in place (quick way to make ways)
The Saddle is wire CNC EDM'ed to match the centers; 4 adjustment screws with the teflon buttons to keep it all nice and tight (tool makers love tight things ;-) )

Ken; the knurl is one of the things i could have done better; the cross slide one was tough as the stock I used only just made the part; I had nothing to hold on; the knurl puts soo much pressure on the bronze it was almost coming out of the 3 jaw (it was a scrap piece I used)

The mill project will be much better as now there will be no pressure to hide it; I've got it 50% designed; I have designed some parts a little different just like the Lathe project; after more than 35years in a trade you do learn something; and I'm almost to that age when stuff starts to fade from memory; the changes are to the head slide/motor area; I think it will be interesting to some
The lathe will be fully digital; I was going to go the chinese scale route; but after finding the linear optical encoder strips by US Digital I'll simply make my own fully enclosed DRO/slides using extruded alumi; plus the compound is only 2 1/2" of travel; so the optical route is much better

On another note for the lathe project; before i do go the whole hog CNC way; I'd like to try to make it stepper powered for the ways; but have it use a manual jog; is there a way to move the steppers with a jog dial; and have multiple resolutions by using a selector switch working in tandem with the jog dial; I'd love to have 0.1-0.010-0.001-0.0001" switchable and have the jog dial marked accordingly; even better would be 2 full sep jog dials (saddle and cross slide) the saddle could be swichable to the compound stepper
So has anyone tried this on a small scale; the full sized Supermax had the exact same setup for manual milling and for zero pick-up

For those interested in the CNC mill project; the travels will be 10" Z 10" Y and 26 or 28" X not exactly small; but still benchtop; I want it big enough for several projects i have in mind; one is a super small fully CNC mill using #17 sized steppers with 2X2X4" travels and a spindle speed of 100,000 rpm

[balsaman]

one is a super small fully CNC mill using #17 sized steppers with 2X2X4" travels and a spindle speed of 100,000 rpm

Interesting,

What will you use it for? Or just a show peice?

I like your lathe so far. Tool and Die makers always impress me because they are very fussy by nature, so the work they do is always impressive.

E

[Stevie]

actually the size would be ok for quite a few projects; you could even make a small RC aircraft engine with that size; granted a lathe would also be needed; but imagine the carbs and stuff it would make
Small engravings was my first thoughts on it; plus the "wow" that really works factor
I guess after seeing the 4mm ball screws you can get; my mind started to grind
As my regular job is not really Tool and Die anymore (just regular old General Machine work) I need to keep my hand in with design and toolpaths

I was working on a 12ft long stellite coated auger shaft this week; the flights and some of the working areas of shaft got re-welded up and needed to be re-machined to size 5.250" dia; with 0.125"/side stellite; needed a 63 finish (tough to get) I used a Makita hand belt sander 1"x30" to get the final finish; worked really good too; run the lathe in reverse (80rpm) and sand with Alumi oxide belts; don't go below 120grit and the stellite will spring to life

The Mill project will be all steel for the main frames of the machine; most likely 1/4 plate mig welded and stress releaved (over-night soak)

Another thought on the lathe; I'll be adding drilled holes with a div head; every 10dgr around the rear part of the collet chuck; with a indent shaft i can then lock the spindle ever 10dgr; I also bilt a small 2 way slide to mount above the spindle; this has a 30,000rpm air powered 1/4" spindle; with this i can machine stuff like hex's while the part is still on center; I have some 25mm anti-aircraft guns to make in 1/48th scale and the muzzle has 6 flash ports; I'll have to use a 0.01"ball mill to make them

[Ken_Shea]

I'm almost to that age when stuff starts to fade from memory
I knew we had something in common

I got a feeling this is going to be a great thread.

Don't quit on us now Stevie.

Ken

[Stevie]

Ken; this July 22nd I'll be 51
Started my apprenticeship in England when I was 15; got payed 5 pounds a week; thats about 25cents/hour; and still managed to get blind drunk every Thursday and Friday night (hehehe)

[Ken_Shea]

blind drunk every Thursday and Friday night

LOL,
And I bet every Saturday morning you said "I am never going to do that again" Right?

[Stevie]

pretty much

I have not got drunk since i moved to Canada in 1980 (well maybe a few times) I find it's just not worth it

[Swede]

I can think of worse places to get drunk than England... love those ales and bitters. A meal in a mug, like a liquid pork chop.

Mice work on the lathe. I also like your concept of a nano-mill. It would actually be perfect for jewelers who mill precious metals directly, or design a wax for a mold.

nano-mill spindle, a dental handpiece perhaps?

Swede

[Swede]

"Mice work on the lathe..." haha obviously I meant "Nice". One thing I forgot to mention, for knurling like yours, if you can find a "Quick" brand coin knurler, it makes exquisite instrument type knurls by cutting rather than cold forming. They are expensive but can occasionally be found used/surplus and bought for a song from someone who doesn't know what he has.

[Stevie]

Good news on the spindle run out front
I made a small tool post grinder and re-cut the spindle taper for the collets

I used a block of 7075 T6 Aluminum and fitted into it the NSK pencil grinder; by holding 1 collet on a mandrel and the other end of the mandrel in the spindle I was able to accurately dial in the exact taper with the compound slide
Then with the pencil grinder going at 60,000rpm I could re-cut the inner taper with the lathe turning (took 5 cuts of about 0.0001 to make it run perfect)

Next project: I'm going to make the lathe CNC controlled; I've ordered a 2 axis PCB board (kit) for stepper motors; with a PC power supply and a breakout board (kit) to connect the 2 axis to a PC via the LPT1 port
I have 6 NEMA17 (35oz/inch approx) sized steppers already; however I think NEMA 23 (100oz/inch) sized will be needed to make it really sing


With this set-up I can make brass or aluminum AA barrels for my scale warship project to my hearts content

[Stevie]

I forgot to add why I've had a change of mind and I am CNC'ing it now; well I figured out how to change it to both; the 7/16" 20 leadscrew for the X axis is still very long; I can fit both a 14 XL groove timing belt pulley and a handwheel; thus a stepper can be outboard of the leadscrew and I can still just manually use the lathe; the cross slide set-up is just a bit harder to change; look at the last but 1 of the pics; the bronze nut/bearing on the cross slide leadscrew; I'll swap this for an extended version; it will still control the leadscrew playbut will extend out and be bored to fit the stepper shaft; a simple support can come off the center 2 wear adjusters on the saddle; this the stepper motor can be screwed to
If I make a few small changes to the compound slide I can even make it stepper powered; then when it's mounted on the 90dgr block and the cutter is in the spindle collet; I can use it like a 3 axis mini mill

[Stevie]

First cut tonight with the lathe; thats a P/Bronze scrap I brought home from work today 5/8" dia
I was just looking to chk the stability of the spindle bearings and the ability to take a good cut; this puppy can really cut; up against the collet (you can see the 90dgr cut) it's almost 3/16"/side and no chatter; wow; then I went for finish cuts in steps with a taper; it worked way better than I thought it would I'm on the slowest speed 1800rpm
I'm still just locking the saddle and using the compound for X axis

I'm going full speed now to CNC it for sure; it will be a great non-ferris lathe (if I use a slower motor I could cut steel)

The tool post grinder I just made is right behind the lathe (excuse the feelers for shims under the tool; I need 0.03" for a 1/4" tool)
The V belt drive can be seen; the motor is under the benchtop and on vertical slides for belt tension (it's own weight)
I need way covers for sure; I'll make them from brass shimstock I made a tiny bending brake some time ago (5" max width 0.02" capacity)

What do you guys think; will Nema 17 steppers drive this; or should I go right to 23's ???

[Hobbiest]

What kind, size, and how many bearings are used in the headstock? Does the saddle ride on linear bearings or wear pads? Igus has a new design similar to your main way. Drylin W series I think. Very nice work!

[Stevie]

The head has 2 6006 SKF Precision-Plus Steel Ball Bearings
you can get them from a bearing supplier or McMaster-Carr page 1015
I made the pulley retaining nut to encompass the job of tensioning the bearings (pre-load)
The head is 6061 T6

Now about the ways; the main bed was CNC machined to + - 0.0005 in all directions; then 2 Thompson 1/2" shafts were screwed down into the 2 1/4X1/4 rabbits (for use of a woodworking term)
The saddle was wire EDM'ed to mate with the 2 round bars with a min clearance; the saddle is made from 7075 T6 same as the bed (in fact for now the cross slide nut is also 7075 T6; with a teflon button for backlash comp)
There are no bearings as such in the set-up; the thompson is very smooth and the wire cut is smooth but with the tiny surface imperfections 1 pass leaves; this is what I wanted; the tiny pits hold my way oil; the screws holding the thompsons also hold a bit of oil that the saddle can pick up; it all seems to work real nice

The way adjusters for the saddle can be seen in the next to the last pic on page 1; again under each 4mm setscrew is a teflon button (I made a small core drill to make them; 1/8" dia x 3/16th long)
So I guess to answer your question there are no linear bearings in the lathe; just round ways for the saddle and dovetails for the other 2 (all dovetails were wire EDM'ed with 0.0005 clearance)

*edit edit* I should also add; the tool post will not be staying; I'll machine up a length of steel with the same shape as the interchangeable tool post holders like can be found in tool suppliers; then I'll cut off as many as possible and make 5 or 6 holders; the holders will be matched to a new post with height adjustment; if I'm going to CNC this I'll need repeatablity in the tool set-ups