5C collets in Cat40 spindles?

[Styron]

Has anyone worked out a good way to mount 5C collets into a Cat 40 flange spindle?

It seems like this would be a useful thing. For me, I'd like to do some lathe operations with my VMC by mounting the part on the spindle and mounting tools on the table. Of course you could also mount mill tools in the 5C collets if you happened to have these laying around.

Thanks,
Josh

[ctate2000]

I have never seen a cat 40 that holds 5C. Can't think of a reason why it would not work. There is no reason you could not do the same thing with DA, ER or TG style collets. These holders are available in most any length. Remember lathes are for turning and mills are for milling you will find it difficult to turn on a machinig center. However, I love to be told "you can't do that" or "that won't work." Always makes me try and I always learn something from the attempt.

[Geof]

I think what you would have to do is get a 1" capacity holder, bore and taper it for the 5C, thread the OD and make a nut to screw on and secure the 5C. I don't see how you could easily draw the 5C in from the back end.

[Styron]

Thanks for the suggestions. I'd like to use 5C because they go up to 1-1/8" and I can buy 4" 3-jaw chucks for 5C. People use lathes to do small mill jobs by mouting the workpiece where the tool normally goes and the tool where the workpiece normally goes. This is very much the same thing in reverse.

Following Geof's suggestion, perhaps the ID of the 1" holder should get tapped to thread in the bottom of the 5C collet. The taper could be put into a nut that threads onto the outside of the 1" holder. Then, backing off the nut would clamp the collet. I don't know how well this would hold concentricty, though. It depends on the threads and tapers to be very well aligned.

Of course, I'd love to be able to buy one of these rather than spending the time making one. It sounds like a nice lathe project, but as you might have guessed, I don't have one. I'd probably have to kick the other car out of the garage to make room.