Thanks Bill for explaining the stub spindle. That or something similar is on the top of my list of things to do when I get the AtomicELS or RELS running.

I need to do 3 or 4 of them to use as a chuck mount in my new cabinet. I am going to mount the chucks on a sliding wall for storage.

I "tried" grinding my original 3 jaw chuck, cannot say I was very successful.

So I bought a 6" 6 jaw which?is really nice. Last month I picked up a great old 3 jaw chuck at a Swap Meet.

Of course I also have a 4 jaw chuck. And of course a Back Plate.

Ralph

On Sat, Jul 8, 2023 at 11:36?AM jf08056 via <jf08056=[email protected]> wrote:

Couple of comments, but I have to admit I did not read all 98 replies so I apologize in advance.

Most old 3 Jaw chucks are still pretty good.? My original 5" Atlas chuck just had bell shaped jaws from wear and I ground the jaws in a few hours with a small router.? That included making a wooden router mount and blocks to pre-load the chuck jaws.? It was not hard and the results were extremely good.? For a bunch of different diameters I tested the runout was about 0.003" or less which is pretty much all you can expect from a typical 3-jaw chuck.? I bought a new Shars 6" chuck with removable jaws and I only use it when I have to.? I still prefer the 5" chuck.

Don't expect to remove and remount anything in a 3-jaw chuck without checking it carefully with an indicator unless you can live with the error.? Maybe you have the magic touch but I don't.? If I need to do this I use a collet if I can.

Mounting a 3-jaw chuck in a 4-jaw chuck might make the 3-jaw perfect but probably only at one diameter.? Also it puts you further from the head-stock and you're starting with a pretty big overhung load.? (If no one answered the stub spindle question, it's a short threaded shaft that matches the lathe's spindle that is long enough to screw into the 3-jaw chuck and still long enough to mount in your 4-jaw chuck.?? Of course if your 4-jaw chuck is big enough you could just mount the 3-jaw chuck body in the jaws of the 4-jaw.)

When I am done cutting a thread I clean it up in the lathe with a stainless steel wire brush.? It works wonders for getting rid of the small imperfections.? For a right-hand thread I generally run the lathe in reverse so the brush feeds itself off the thread,?? I do this on aluminum too with a soft stainless steel brush.? For a big thread you can clean it up with a triangular file if you have to.

That's it.? Take it or leave it.
?
Jim

And some days you hit it on the mark.??

I spent the last few weeks remaking the above compound dovetail at the correct height so that I don't have to adjust the QCTP holders if I change from this new compound over to a solid pedestal or if I even remove the MLA cross slide and go all the way back to Atlas stock cross slide and compound.

I learned some stuff again.? Probably things y'all already know.
On the first go around (above), I used my mill mostly. It has some parallelism issues and the horizontal mill cutters were dull.? Noisy.? SWMBO complained.

I decided to try the 4 jaw chuck on the Atlas to face the stock down to thickness this time.? This worked great.? Nice flat surface and good finish.
However, the chuck was old and worn so when I flipped the stock over to make a parallel cut, it was not so good.
After trying all sorts of make-ready and shims that did not work I decided to do the trick Joe Pie showed in a YouTube.

I drilled and tapped holes in the chuck, mounted some aluminum cylinders and turned them flat.



The next pass with the cutter on the raw stock gave me parallel under 0.001.????? Yawsa!



I took light cuts because of the interrupted cuts.? Initially I was running in back gear but that made a lot of noise and the back gear handle wanted to pop out.? I wound up changing the belting arrangement to the slowest I could run without back gear and that was a lot better.? Coincidentally not much of a speed change from where I was in back gear.

So those two things are what I learned about my lathe and its capabilities.

The rest was on the mill.? Cutting light and slow.? Many passes, many measurement checks.? A few paper shims to get parallelism perfect.
Nailed it.




In the below image, you can see one of the mistakes I fixed from before.? I had made the dovetail way too narrow and the gib tilted all wonky.
This time you can see the good gib fit.? The slide is butter smooth with the gib tighter than I have ever had it before.
I can yank on the QCTP hard and not see any oil gapping at the compound slide interface.
Solid pedestal is in the pic just for visual height comparison.



Happy........

Feel free to correct me, but I thought the runout in 3 jaw chucks mainly comes from the scroll threads. Won't this error vary by the thickness of the workpiece because the jaws will stop at different places in the scroll? If true, a Buck chuck or other adjustable chuck can only be centered for a fixed diameter and other diameter workpieces will still have runout. I understand that wear in the jaws and scroll will increase runout over time, but I am specifically addressing a new 3 jaw chuck. Grinding the jaws can correct worn jaws, but it will never turn true new or ground through the range of jaw movement.

On 7/7/2023 11:33 PM, mike allen wrote:

There's several youtubes on mounting a backplate to a chuck & making the backplate fit your lathe . When you buy a chuck & new 1 1/2 x 8 backplate you don't just bolt the backplate to the chuck & start using it . Theres steps you need to go through to get the best results using your new chuck .

Pick any of the tubes , probably the first batch , I don't know . This Old Tony probably has one of the better ones .

Little machine Shop used to have a write up on their site but I couldn't find it though I didn't find a bunch of time there . If after watching a tube or 3 & you still don't get it let us know & one of us will tell the procedure they did to mount theirs . Odd's are 5 people will have 5 different procedures but the end result is the same . I did my first chuck the old way of installing & removing & testing the backplate till I got it right . I probably spent more time removing & reinstalling then I actually did cutting chips .

I decided to work smarter not harder & when a loose headstok with spindle came available for my SOuth Bend 9A I bought it for 25 bucks . One of the best 25 buck's I ever spent , well maybe not as the 25 I spent before a concert ways back , but thats for another forum .

remember , when your through learning your through .

animal

On 7/7/23 6:17 PM, Greg via groups.io wrote:

I think I'm confused... ;-)

Sent from my T-Mobile 4G LTE Device

-------- Original message --------

From: mike allen <animal@...>

Date: 7/7/23 5:34 PM (GMT-08:00)

To: [email protected]

Subject: Re: [atlas-craftsman IO] I Need a 3 Jaw Chuck

The stub spindle is something you make & thread on your lathe that duplicates teh threaded end of your spindle . That way when your making a backplate to fit your lathe you don't have to keep taking your chuck off the spindle to see if your stub spindle fits .

animal

On 7/7/23 4:59 PM, Ralph Hulslander wrote:

Yeah Bill, What is a stub spindle and how does one use it?

Ralph

On Fri, Jul 7, 2023 at 7:50?PM vt_biketim <tchock59@...> wrote:

>>With a decent 4-jaw and a stub spindle you get better accuracy than you would with all but the best 3-jaw chucks<<

What?do you mean by a "stub spindle"?

Tim

On Fri, Jul 7, 2023 at 12:22?PM Bill in OKC too via <wmrmeyers=[email protected]> wrote:

Oh, if you buy an older chuck, you're taking pot luck that it will be useable. I put a Shars 4-jaw 6" chuck on my Atlas when I bought it, because the Atlas chuck that came with it was out by .014".? And the Shars was cheaper than an original Atlas chuck. Which might be good, but might not. I would love to put a Buck Adjust-tru chuck on it, but they cost more than I paid for any of my larger lathes. If I were working as a machinist, that would probably be easily justifiable. As a hobbyist, nope! YMMV!

With a decent 4-jaw and a stub spindle you get better accuracy than you would with all but the best 3-jaw chucks, and less time spent dialing parts in. You don't always need the accuracy of a 4-jaw, but I don't see it hurting anything unless you're working for high production. Your needs are unlikely to match mine, so my advise may not fit at all, but! A stub spindle will speed you up with a 3 jaw chuck, too, so very worth doing.

Bill in OKC?

There's several youtubes on mounting a backplate to a chuck & making the backplate fit your lathe . When you buy a chuck & new 1 1/2 x 8 backplate you don't just bolt the backplate to the chuck & start using it . Theres steps you need to go through to get the best results using your new chuck .

Pick any of the tubes , probably the first batch , I don't know . This Old Tony probably has one of the better ones .

Little machine Shop used to have a write up on their site but I couldn't find it though I didn't find a bunch of time there . If after watching a tube or 3 & you still don't get it let us know & one of us will tell the procedure they did to mount theirs . Odd's are 5 people will have 5 different procedures but the end result is the same . I did my first chuck the old way of installing & removing & testing the backplate till I got it right . I probably spent more time removing & reinstalling then I actually did cutting chips .

I decided to work smarter not harder & when a loose headstok with spindle came available for my SOuth Bend 9A I bought it for 25 bucks . One of the best 25 buck's I ever spent , well maybe not as the 25 I spent before a concert ways back , but thats for another forum .

remember , when your through learning your through .

animal

On 7/7/23 6:17 PM, Greg via groups.io wrote:

I think I'm confused... ;-)

Sent from my T-Mobile 4G LTE Device

-------- Original message --------

From: mike allen <animal@...>

Date: 7/7/23 5:34 PM (GMT-08:00)

To: [email protected]

Subject: Re: [atlas-craftsman IO] I Need a 3 Jaw Chuck

The stub spindle is something you make & thread on your lathe that duplicates teh threaded end of your spindle . That way when your making a backplate to fit your lathe you don't have to keep taking your chuck off the spindle to see if your stub spindle fits .

animal

On 7/7/23 4:59 PM, Ralph Hulslander wrote:

Yeah Bill, What is a stub spindle and how does one use it?

Ralph

On Fri, Jul 7, 2023 at 7:50?PM vt_biketim <tchock59@...> wrote:

>>With a decent 4-jaw and a stub spindle you get better accuracy than you would with all but the best 3-jaw chucks<<

What?do you mean by a "stub spindle"?

Tim

On Fri, Jul 7, 2023 at 12:22?PM Bill in OKC too via <wmrmeyers=[email protected]> wrote:

Oh, if you buy an older chuck, you're taking pot luck that it will be useable. I put a Shars 4-jaw 6" chuck on my Atlas when I bought it, because the Atlas chuck that came with it was out by .014".? And the Shars was cheaper than an original Atlas chuck. Which might be good, but might not. I would love to put a Buck Adjust-tru chuck on it, but they cost more than I paid for any of my larger lathes. If I were working as a machinist, that would probably be easily justifiable. As a hobbyist, nope! YMMV!

With a decent 4-jaw and a stub spindle you get better accuracy than you would with all but the best 3-jaw chucks, and less time spent dialing parts in. You don't always need the accuracy of a 4-jaw, but I don't see it hurting anything unless you're working for high production. Your needs are unlikely to match mine, so my advise may not fit at all, but! A stub spindle will speed you up with a 3 jaw chuck, too, so very worth doing.

Bill in OKC?

I think I'm confused... ;-)

Sent from my T-Mobile 4G LTE Device

-------- Original message --------

From: mike allen <animal@...>

Date: 7/7/23 5:34 PM (GMT-08:00)

To: [email protected]

Subject: Re: [atlas-craftsman IO] I Need a 3 Jaw Chuck

The stub spindle is something you make & thread on your lathe that duplicates teh threaded end of your spindle . That way when your making a backplate to fit your lathe you don't have to keep taking your chuck off the spindle to see if your stub spindle fits .

animal

On 7/7/23 4:59 PM, Ralph Hulslander wrote:

Yeah Bill, What is a stub spindle and how does one use it?

Ralph

On Fri, Jul 7, 2023 at 7:50?PM vt_biketim <tchock59@...> wrote:

>>With a decent 4-jaw and a stub spindle you get better accuracy than you would with all but the best 3-jaw chucks<<

What?do you mean by a "stub spindle"?

Tim

On Fri, Jul 7, 2023 at 12:22?PM Bill in OKC too via <wmrmeyers=[email protected]> wrote:

Oh, if you buy an older chuck, you're taking pot luck that it will be useable. I put a Shars 4-jaw 6" chuck on my Atlas when I bought it, because the Atlas chuck that came with it was out by .014".? And the Shars was cheaper than an original Atlas chuck. Which might be good, but might not. I would love to put a Buck Adjust-tru chuck on it, but they cost more than I paid for any of my larger lathes. If I were working as a machinist, that would probably be easily justifiable. As a hobbyist, nope! YMMV!

With a decent 4-jaw and a stub spindle you get better accuracy than you would with all but the best 3-jaw chucks, and less time spent dialing parts in. You don't always need the accuracy of a 4-jaw, but I don't see it hurting anything unless you're working for high production. Your needs are unlikely to match mine, so my advise may not fit at all, but! A stub spindle will speed you up with a 3 jaw chuck, too, so very worth doing.

Bill in OKC?

>>With a decent 4-jaw and a stub spindle you get better accuracy than you would with all but the best 3-jaw chucks<<

What?do you mean by a "stub spindle"?

Tim

On Fri, Jul 7, 2023 at 12:22?PM Bill in OKC too via <wmrmeyers=[email protected]> wrote:

Oh, if you buy an older chuck, you're taking pot luck that it will be useable. I put a Shars 4-jaw 6" chuck on my Atlas when I bought it, because the Atlas chuck that came with it was out by .014".? And the Shars was cheaper than an original Atlas chuck. Which might be good, but might not. I would love to put a Buck Adjust-tru chuck on it, but they cost more than I paid for any of my larger lathes. If I were working as a machinist, that would probably be easily justifiable. As a hobbyist, nope! YMMV!

With a decent 4-jaw and a stub spindle you get better accuracy than you would with all but the best 3-jaw chucks, and less time spent dialing parts in. You don't always need the accuracy of a 4-jaw, but I don't see it hurting anything unless you're working for high production. Your needs are unlikely to match mine, so my advise may not fit at all, but! A stub spindle will speed you up with a 3 jaw chuck, too, so very worth doing.

Bill in OKC?

The stub spindle is something you make & thread on your lathe that duplicates teh threaded end of your spindle . That way when your making a backplate to fit your lathe you don't have to keep taking your chuck off the spindle to see if your stub spindle fits .

animal

Yeah Bill, What is a stub spindle and how does one use it?

Ralph

On Fri, Jul 7, 2023 at 7:50?PM vt_biketim <tchock59@...> wrote:

>>With a decent 4-jaw and a stub spindle you get better accuracy than you would with all but the best 3-jaw chucks<<

What?do you mean by a "stub spindle"?

Tim

On Fri, Jul 7, 2023 at 12:22?PM Bill in OKC too via <wmrmeyers=[email protected]> wrote:

Oh, if you buy an older chuck, you're taking pot luck that it will be useable. I put a Shars 4-jaw 6" chuck on my Atlas when I bought it, because the Atlas chuck that came with it was out by .014".? And the Shars was cheaper than an original Atlas chuck. Which might be good, but might not. I would love to put a Buck Adjust-tru chuck on it, but they cost more than I paid for any of my larger lathes. If I were working as a machinist, that would probably be easily justifiable. As a hobbyist, nope! YMMV!

With a decent 4-jaw and a stub spindle you get better accuracy than you would with all but the best 3-jaw chucks, and less time spent dialing parts in. You don't always need the accuracy of a 4-jaw, but I don't see it hurting anything unless you're working for high production. Your needs are unlikely to match mine, so my advise may not fit at all, but! A stub spindle will speed you up with a 3 jaw chuck, too, so very worth doing.

Bill in OKC?

Yeah Bill, What is a stub spindle and how does one use it?

Ralph

On Fri, Jul 7, 2023 at 7:50?PM vt_biketim <tchock59@...> wrote:

>>With a decent 4-jaw and a stub spindle you get better accuracy than you would with all but the best 3-jaw chucks<<

What?do you mean by a "stub spindle"?

Tim

On Fri, Jul 7, 2023 at 12:22?PM Bill in OKC too via <wmrmeyers=[email protected]> wrote:

Oh, if you buy an older chuck, you're taking pot luck that it will be useable. I put a Shars 4-jaw 6" chuck on my Atlas when I bought it, because the Atlas chuck that came with it was out by .014".? And the Shars was cheaper than an original Atlas chuck. Which might be good, but might not. I would love to put a Buck Adjust-tru chuck on it, but they cost more than I paid for any of my larger lathes. If I were working as a machinist, that would probably be easily justifiable. As a hobbyist, nope! YMMV!

With a decent 4-jaw and a stub spindle you get better accuracy than you would with all but the best 3-jaw chucks, and less time spent dialing parts in. You don't always need the accuracy of a 4-jaw, but I don't see it hurting anything unless you're working for high production. Your needs are unlikely to match mine, so my advise may not fit at all, but! A stub spindle will speed you up with a 3 jaw chuck, too, so very worth doing.

Bill in OKC?