The mill spindle is R8, and I want to mount a 3" or 4" chuck in it. I can't find any type of mount for a chuck, but I'm not sure if I just don't know the correct keywords for whatever I need for this?

My other thought was to machine a mount plate that's essentially a disk with a 3/4" shaft on it, and the shaft would go in a 3/4" R8 collet in the mill spindle. The chuck would then get bolted to the disk part. But if I can find a ready-made solution I'd prefer that route.

Ideas, thoughts, pointers?

Thanks,
-Neil.

Your plate on a 3/4" shank idea is probably close to the best; the only change that might make it more rigid is to use a face mill holder and make a plate to fit this. There have been a few threads about putting a chuck on a mill spindle and I don't think anyone found a ready made solution.

Here is a link that takes you to one thread, these are dealing with larger size CNC mills:

http://www.cnczone.com/forums/showthread.php?t=51075

And here is one I did for fun which shows what is possible:

http://www.cnczone.com/forums/showthread.php?p=406398#post406398

There's a guy on e-bay selling 3" and 4", 3 jaw chucks that have an r8 taper. Price was pretty cheap too.

http://cgi.ebay.com/BRIDGEPORT-R8-SHANK-3-SELF-CENTERING-3-JAW-CHUCK-NEW_W0QQitemZ350024633516QQihZ022QQcategoryZ25292QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

Paul

That would be nice for a fourth axis using a spare R-8 spindle head from an X2. Limited by no through hole though. It does spark some ideas. ;)

If you need a thru hole look at the 5C collet stuff.

There's a guy on e-bay selling 3" and 4", 3 jaw chucks that have an r8 taper. Price was pretty cheap too.

http://cgi.ebay.com/BRIDGEPORT-R8-SHANK-3-SELF-CENTERING-3-JAW-CHUCK-NEW_W0QQitemZ350024633516QQihZ022QQcategoryZ25292QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

Paul


Dibs!!! :)

So I picked up one of these from an Ebay seller for $40 -- a 4" chuck with an R8 mount. I wasn't too thrilled by the seller, but the product is decent. I did not slip smoothly into the R8 spindle on my mill, but it wasn't too bad -- I just had to pull it up with the drawbar. But the main purpose was met -- to do some CNC turning on my mill. Pretty neat! I should measure with the dial indicator to see how concentric it is though.

Thanks,
-Neil.