Collet Chuck information

Dusty

(Bill)
Premium Member
Ya, that sounds like Craftex. The spindle plate and chuck have a registration and the chuck bolts straight on. The registration and bolt patterns are standardized for different chuck sizes. You would need to find a collet chuck with mounting plate that has the same registration and bolt pattern.

https://littlemachineshop.com/info/lathechuck.php

There are some options here, but their shipping is usually a killer.

Search For... - LittleMachineShop.com

How big is your chuck?

Hey Craig you're correct about my 3 & 4 jaw chucks having a registration, my 3 jaw chuck is 4 & 15/16" in diameter. As you say there are options and work arounds to what I'm thinking although it may take time assembling the components. Should it become too pricy or cumbersome to attach and remove I would likely pass on the idea. Would be handy to have although not necessary.
 
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PeterT

Ultra Member
Premium Member
Sorry I was looking at the wrong lathe. Assuming its like this one then drawbar looks feasible. But as mentioned, with an MT4 ER arbor, stock protrusion to the left is limited to what the collet grips because the arbor is solid.

1621816818394.png 1621816996779.png
 

PeterT

Ultra Member
Premium Member
Depending on what you are trying to accomplish, another option is to chuck an ER collet block in your 4J. Dial it in precisely with DTI against a gripped dowel pin, but you only have to do that once. Now you can loosen the ER nut, insert or replace new stock & it should maintain concentricity because the 4J grip is maintained. So you could do a batch of parts. And this will also allow stock to protrude into the spindle hole.
They also make hex blocks but there is no guarantee your 3J will grip it without runout, but maybe on that lathe you have a means to adjust? Anyways, food for thought.

1621817269932.png 1621817524381.png
 

Dusty

(Bill)
Premium Member
Depending on what you are trying to accomplish, another option is to chuck an ER collet block in your 4J. Dial it in precisely with DTI against a gripped dowel pin, but you only have to do that once. Now you can loosen the ER nut, insert or replace new stock & it should maintain concentricity because the 4J grip is maintained. So you could do a batch of parts. And this will also allow stock to protrude into the spindle hole.
They also make hex blocks but there is no guarantee your 3J will grip it without runout, but maybe on that lathe you have a means to adjust? Anyways, food for thought.

View attachment 14940View attachment 14941

Isn't this similar to what John is suggesting in his post #11?
 

PeterT

Ultra Member
Premium Member
Maybe. He might be suggesting making one from scratch to adapt to your lathe in a different way (not sure really).
I'm just mentioning an off the shelf ER block that which is ready to go, hardened & ground on all surfaces. But if you don't have a 4J chuck & no plans to use one, then other solutions may score higher.
 

Dusty

(Bill)
Premium Member
Maybe. He might be suggesting making one from scratch to adapt to your lathe in a different way (not sure really).
I'm just mentioning an off the shelf ER block that which is ready to go, hardened & ground on all surfaces. But if you don't have a 4J chuck & no plans to use one, then other solutions may score higher.

Thanks, yes I have a 4 jaw chuck, something to think on.
 

YYCHM

(Craig)
Premium Member
Hey Craig you're correct about my 3 & 4 jaw chucks having a registration, my 3 jaw chuck is 4 & 15/16" in diameter. As you say there are options and work arounds to what I'm thinking although it may take time assembling the components. Should it become too pricy or cumbersome to attach and remove I would likely pass on the idea. Would be handy to have although not necessary.

If your chuck conforms to the LMS specs I linked to, there is a pretty good chance you can find an off the shelf 5C adapter that will work.

This should work for you as you have a 5" chuck...

5C Collet Chuck | 5C Collet Holder | LittleMachineShop

I'm sure there are less expensive ones out there.
 
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Johnwa

Ultra Member
@YYCHM I want to mount one on my Southbend and 1 on my SM. I’ve failed twice trying to make a tight fitting threaded backplate for the Southbend. . I haven’t attempted the SM yet. It takes a D1-4 backplate.
 

YYCHM

(Craig)
Premium Member
@YYCHM I want to mount one on my Southbend and 1 on my SM. I’ve failed twice trying to make a tight fitting threaded backplate for the Southbend. . I haven’t attempted the SM yet. It takes a D1-4 backplate.

Want to mount one for what purpose?
 

Johnwa

Ultra Member
@YYCHM Colletsare great when you’re working with round stock. You don’t have to fiddle with centring your work and you can take it out and put it back in. All assuming that you have an accurate collet and chuck. I have set of 3mt and 3c collets. The 3mt don’t allow for through hole, and the 3c maxes out at ½”.
 

John Conroy

member
Premium Member
John I bought one of these. After a bit of fiddling around the run out is about .001", but that's good enough for most 9f the work I do. Whe I complained that the runout was twice as much as his claimed .0006" or less he refunded half the purchase price. He also sells them with semi finished backplate for threaded spindles.

https://www.ebay.ca/itm/271667554173
 

DavidR8

Scrap maker
Administrator
Moderator
Premium Member
That’s the 5C chuck that I have. Through some miracle I got it down to .0003 runout.
 
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