Chuck for Rotary Table

I have a 150mm diameter rotary table for my mill.

I am thinking of getting a 125mm diameter self centering 3 jaw or 4 jaw chuck for it - it may be the 4 jaw as that has 4 holding down bolts and the table has 4 tee slots - rather than a 100mm diameter chuck.

Any reason why the 125mm diameter chuck would not work on a 150mm diameter table?

Chris

Hi Chris,

A 125mm chuck should work OK on your rotary table. I assume you will use a front mount chuck, like this (yes it's a 3-jaw):

You should be able to use a larger chuck if the mounting holes coincide with the T-slots of the rotary table. I have a smaller rotary table - 100mm - and uses an adapter plate to mount an 80mm chuck. With a front mount chuck you may may not need the adapter plate.

Thor

Edited By Thor on 27/04/2014 07:14:36

Thor, I can't get my head around an adapter plate, ie how you fasten the chuck to the plate and the plate to the rotary table.

Can you put up a photo of your adapter plate.

Hi Chris, I would use a chuck that has 4 bolts to match the 4 slots on your rotary table. I have a 150mm chuck on a 150mm rotary table. It is held by tee nuts and a disc which is located on the rotary table center.

If you are buying a chuck just for the rotary table I would go for one which is the same diameter as the table. A 4-jaw chuck is more versatile. It can hold odd shapes and is more accurate for centering round parts.

Hi Chris

If you have a chuck like Paul's that fits the table then that is probably the the best solution. In my case the chuck is the type with the mounting bolts at the back. My solution was to make a backplate from a piece of 1/4" plate which was a little larger in diameter than the chuck. The photo probably avoids further explanation!

You will see that this IS a 125mm chuck on a 150mm table -  so yes it does work!

Regards

Norman

Edited By NJH on 27/04/2014 09:28:49

"The photo probably avoids further explanation" or it would have done if I had thought to add that the chuck is fixed through the backplate ( from the table side) by 4 socket headed countersunk screws!

N

... and there was me, thinking that you had photographed it from a "trick" angle, with the curtain on a table.

Seriously though ... wouldn't there be three screws holding a 3-jaw chuck?

MichaelG.

I guess you may well be right Michael - three screws would be more likely than four to hold the chuck. I could confirm this for you but that would mean that I had to take the chuck off the table - and then go through the process of getting it centred again! ( In truth that is not too difficult - I made a long bar with a No2 MT on one end and, with this in the socket in the table and the chuck closed onto the parallel portion, it's pretty close.)

The curtain in the image is covering up some top secret project I was working on ( or maybe it was to save tidying the bench!)

Norman

Chris,

Depending upon your lathe, there is a big advantage in making your lathe chuck fit onto your rotary table. That way you can turn a piece on the lathe and transfer the chuck - complete with turned work in situ - onto your rotary table to make squares and flats on it.

See my website to see what my fitting looks like :-

**LINK**

Kind Regards

David H

avoid the plate part with this ror example (other lathes available).

Hi Chris,

sorry I am so late to respond to your question. I found a video that you may find useful. It shows how a chuck is mounted on a rotary table using an adapter plate.

Thor

Edited By Thor on 27/04/2014 18:36:41

Hi - thanks for all the replies, I think it will be the 125mm diameter 4 jaw self-centering I go for as:

a) 125mm seems to be a popular choice of others,

b) can't seem to be able to source a 150mm diameter chuck at the suppliers I check out, the next size up from 125mm seems to be 160mm, and

c) a 4 jaw will give 4 fixing holes and the table has 4 slots, so that will match up.

Thanks also to those posting the links to various other sites of interest, most interesting and informative, always gives food for thought and helps the little grey cells!

Out of interest, does anybody have a good idea of what a good target run-out on an 'Asian' chuck should be?

Chris

The standard for my Zither chuck is 0.080mm at 50mm using the master pinion (marked 0) or at 12mm using any pinion.

In practice it's rather better than that but you have to make sure the scroll and jaws are clean to get the good results.

Neil

Chris, for a four jaw chuck it's as good as your best dti and your patience.

Regards * Danny M *

Not when it's self centring.

Steve

I mounted my 125mm lathe chuck using Norman's method. (The cast iron was found in the base of a patio heater...)

What I did find though, was that there is very little room left on the machine bed once there is a tailstock, 150mm table and 125mm chuck set up. I now use my collet chuck when I can to minimise the wasted bed space.

Steve