Attaching larger lathe chuck to rotary table...

[barts]

I'd like to be able to put my 10" & 12" A (not sure which one, but short tapered nose, four bolts) series 3 & 4 jaw chucks on my 10" Phase II rotary table for doing bolt holes, gears; I don't happen to have any smaller chucks. The center of the table has a MT2 taper I believe, which might serve to indicate where the center is but isn't strong enough to coerce the chuck into the right position, even sitting free on the table. I guess the 4 jaw doesn't need to be centered - only the work held by the chuck does - but since many things that need bolt patterns are already round, I could save some time by using the 3 jaw.

Any pointers or ideas- or does everyone use DROs for bolt circles now? It sure seems handy to be able to use a chuck on a rotary table...

- Bart

[Boucher]

I have a small 6” Yusha tilting Indexer with a 3” 3-jaw chuck and it is very handy for doing bolt / hole patterns. I find that it gets used in the horizontal position to locate holes around the OD of shafts more than for hole patterns. If your rotary table is both horizontal and vertical you might keep that in mind. I recently purchased a HF motor lift to use with the 10” rotary table. It will probably see more use now but weight is a problem if you put a big chuck on a big rotary table. Can you lift it?
My rotary table came out of a commercial machine shop and it had a 1 ½” aluminum plate with lots of holes tapped in it.

[Gary Paine]

The center of the table has a MT2 taper I believe, ...Any pointers or ideas- or does everyone use DROs for bolt circles now? It sure seems handy to be able to use a chuck on a rotary table...- Bart

You didn't say what kind of chuck mounting you use, but I'd suggest making an adapter that perfectly centers your lathe chuck to the table. Indicate the MT2 and assure it is machined properly (mine was a bit out on a Palmgren) and if it is right, you can incorporate that into your design. Include a perfectly cut center hole for a centering pin.
Spending the time to make such an adapter pays back many times when you want to move work from the lathe to the mill and maybe back to the lathe without removing it from the chuck.

[barts]

I'd suggest making an adapter that perfectly centers your lathe chuck to the table. Indicate the MT2 and assure it is machined properly (mine was a bit out on a Palmgren) and if it is right, you can incorporate that into your design. Include a perfectly cut center hole for a centering pin.
Spending the time to make such an adapter pays back many times when you want to move work from the lathe to the mill and maybe back to the lathe without removing it from the chuck.

That's pretty much what I'd have to do. It's a little tricky, as the chucks are A2-5 (they bolt on outer circle of the lathe's A1-5 spindle). The dimensions of the spindle nose are here: http://www.lathes.co.uk/latheparts/page9.html; I'm sure the taper will be exciting to get right. Doing this properly would mean grinding, something I'm not set up for.

Another choice is to buy a plain back four jaw chuck like the Grizzly G9866, and machine an adaptor plate for that - a simpler task.

- Bart

[goodscrap]

have you considered using a brake rotor as and adaptor, you can get one that overhangs the table slightly and machine a register in the back of it; so it can be quickly added without the need to dial it in each time unless you're chasing close tolerences.

i thought i'd seen the idea on here but can't find it, best i can do is post no. 7 in this thread http://www.practicalmachinist.com/vb...-chuck-185164/

Cheers
Brian