How do you attach a 3-jaw chuck to a mill's table?

mill's table with three T-slots?

How does somebody who has a "clue" do it, or how do "I" do it?

Do you mean to just bolt the chuck down to use it as a round stock vise?

I like to make things that I can repeat. I might cut some flat stock with an alignment key I can place in the t-slots of the table, then flip it over and mill it flat. Then cut a deep pocket in the "center" to use for future zeroing. Then cut a shallower snug slip fit pocket in the plate to set the chuck down into. Clamp, bolt, season to taste from there.

snipped-for-privacy@googlegroups.com...

Well, geez! If you want to do it the asy way. LOL.

-I like to make things that I can repeat.

In this case you can align the table, chuck and spindle very easily by clamping an edge finder in both a mill collet and the chuck and moving the chuck until the split edges align, or don't catch a fingernail slid across in either direction. That's how I set my rotary table to

It works on a lathe too. jsw

mill's table with three T-slots?

I have a backplate about 8" in diameter on the back of my 6 1/4" chuck and just clamp it to the BP table with a couple of common clamping bars with a bit of Al in between to stop marring of the upper surface. The back of the backplate also has a removable spigot that locates in the centre of my 10" rotary table and the back plate has 6 holes spaced around it to allow it to be held down with T nuts and cap head screws in the rotary table slots.

How about drilling and doweling whatever you use as a mounting flange? Pressfit in the flange, smooth slide into the table.

table with three T-slots?

Mine sits on a 1/2" Al plate which gets clamped to wherever by the usual clamps.

Michael Koblic, Campbell River, BC

mill's table with three T-slots?

Hi,

Clamps on the chuck face ,or a custom size backplate to clamp onto. Thanks for the ideas. A backplate was the way I was leaning, as clamps could interfere with what I'll want to hold.

BTW, The below link is what peaked my interest in other ideas. It's an IMTS show highlight video from Hurco, I have no connection with Hurco.

At about 2:15 into it, you can clearly see two 3-jaw chucks mounted to a mill table, but I can't for the life of me see how the heck they are held down. Can you?

Sorry for the long link.

Thanks again, PaulS

table, but I can't for the life of me see how the heck they are held down. Can you?

Hmm ... it might be a removable T-slotted plate with the chucks bolted in place from the back.

Or -- it might be a flat backplate attached to two T-nuts (they both seem to be centered over slots), and the chuck then bolted down to the plates using through screws accessible from the front, as is common for adjust-tru style chucks.

Enjoy, DoN.

If you want to be clever and mysterious you could thread a center-drilled plug with the spindle thread and drop it over a tee slot bolt. It might shift under a heavy cut.

Unless you are careful to set up so the cutting forces would tighten rather than loosen -- which would require a left-hand-cut endmill in most cases -- unless you were milling out a cylindrical pocket on center in the end of the workpiece. :-) Maybe even a square or rectangular pocket as long as it is centered over the axis of the chuck.

The real question is: "Why try to be mysterious if it makes the task harder?" :-)

Enjoy, DoN.

How about making an oversized back plate. On it - have dog holes for the table. And naturally the mounting holes for the chuck.

This way there isn't a rotation on a screw shaft.

Mart> >

Hi Guys,

I can't see any sub plates or added backplates in the video, they might be there though.

Might also be through-bolted from the top. But can you really do that with a scroll chuck?

Anyway, I've not seen/heard anything that makes much sense to me yet.

A mystery indeed.

Asking Hurco (even if you could reach someone with the answer) just feels like defeat.

Machinists are supposed to be a bright bunch. I should be able to figure this out.

Could it be a plug that expands in the chuck's bore as you tighten a bolt through it into a tee-nut in the table's slot?

Plug's hight in the bore would have to be below the plane of the jaw slots. On my 6" 3-jaw that's about 1.25" of meat in the bore to grip.

Scratching my head on this one still...

PaulS

If the chuck has front mounting holes the tee-slot mounting plate could be hidden beneath it.

My suggestion of a screw-in washer was facetious since it wouldn't hold very well, but it could be practical with more work. Machine a tongue on one end of the threaded plug that fits the tee slot and drill the chuck backplate spigot radially for a screw that locks it to the plug. Secure the plug to the table with a centered tee slot bolt and nut. The tongue and locking screw keep the chuck from unscrewing.

jsw

e there though.

with a scroll chuck?

els like defeat.

through it into a tee-nut in the table's slot?

s.  On my 6" 3-jaw that's about 1.25" of meat in the bore to grip.

I use lathe chucks on a rotary table, table has a large hole in the center extending past the T-slots. I just made a replica spindle nose, slotted the bottom for a bar that fits the T-slot and use a bolt through the center of the spindle nose clone to clamp the bar to the table. I can spin any chuck I want onto the table, with or without workpiece from lathe operations.

Stan

I have a BS-0 dividing head that doesn't yet have a chuck fitted:

The spindle thread is 1-1/2 - 8.

How careful do you have to be of the cutting force direction to keep the chuck from unscrewing?

jsw

In my experience Jim I have found that if the chuck is spun on smartly it will be tight enough to stay threaded on when milling. When milling on the OD of a part in the chuck the cutting forces will tend to unscrew the chuck but it has not happened to me. And I've used screw on chucks a lot when milling parts using the dividing head. In fact, the problem I have is getting the chuck back off if I screw it on too smartly. When I machine adapters to use chucks with threads I do all the work in one chucking so that the shoulder that the chuck tightens against is square with a line through the pitch diameter. This helps greatly keeping the chuck on. Eric

mill's table with three T-slots?

YES!

mill's table with three T-slots?

How is the chuck mounted to the AL plate?