Is it ok the hold a small lathe chuck in a larger one

I sometimes find my chuck is a bit large for some of the work I do. I have a small Myford chuck and was wondering if its ok to hold that in the bigger chuck?

Should be OK but remember that the run-out errors may accumulate.

Russell

The turners at work regularly hold a small 4 jaw in the normal, larger, 3 jaw as it is easier than swapping chucks.

Nigel B

Yep. Not an issue. I do it regularly when working on material too fine for large chuck.

Regards,

Phil.

Depending on the size of the larger chuck you may also like to consider using a six sided collet block if you need to hold round stock...

**LINK**

Thanks guys, good to know its ok. Those collet bocks also look like and interesting idea

Avoid holding a steel bodied chuck in another chuck as they have been known to slip out with obvious consquences.

Neil

I would admit to having used the 2" sherline chucks in the outside jaws of a 5" 3 jaw chuck, and to be honest I expected to see a runout error of some sort but didn't notice anything unusual, it appeared to turn true by eye atleast.

It's very handy to use for very small work pieces where the bigger chuck would crush the material. You just have to be careful not to damage the chuck you are holding.

Michael W

Edited By Michael-w on 07/04/2017 10:58:21

Edited By mechman48 on 07/04/2017 10:48:35

Can't remember what the job was, but I held the 2 1/4" four jaw chuck from the Super Adept in the 8" 3 jaw chuck on my big lathe.

Ian S C

With my ER32 collets I go down to 6mm, but sometimes need to hold stuff smaller than that. In that situation I use an ER11 collet chuck on a cylindrical shaft held in a 10mm ER32 collet. So that's a chuck in a chuck too. The whole ER11 range of collets & collet chuck on a shaft cost the same as 1 ER 32 collet.

When drilling precise small holes using my milling head on the lathe, I use this method rather than use the Jacobs chuck (the Jacobs can't grip drills smaller than 2.9mm either).

Regards,

Richard.

If you assess the runout of each chuck you should be able to rotate the smaller one to compensate it out. As mentioned above hard steel jaws will not grip well a hard steel chuck body. Interpose aluminium drinks can shim or perhaps rings of copper pipe bearing in mind that pipe is not extruded with even wall thickness.

I would consider it as bad practice with conventional chucks. I was not taught not to do it (I doubt if my instructor had ever even considered the idea). I think the increase in overhang would be the major objection.

Obviously mounting something like a lantern chuck (for shortening small screws) in a large chuck or collet chuck is OK.

JA

Yeah I agree with that, I was talking about small fixtures that you can hold in the palm of your hand, trying to hold a full bodied chuck inside another would probably be venturing into dangerous territory!

I would say if you find you're making a habit of it, consider making a back plate adapter rather than "piggy-backing" the small one.

Michael W

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I saw this done only today in a commercial workshop.

A small 125mm 4 jaw held in a much larger 3 jaw. - The big 3 jaw was using soft jaws though so I suppose the gripping was better.

I imagine it's one of those cases where "It ain't what you do it's the way that you do it" that matters.

Nick

lists two different nuts.

which is better one to have?

Ball bearing every time, and only 80 pence more.

Neil

great cheers.

You could put the whole of a Super Adept in an 8" 4 jaw.

You could put the whole of a Super Adept in an 8" 4 jaw

To turn it into something useful ?

Nigel B