CNC lathe - off center machining

I would make a bushing with the I.D. off center that would fit into your chuck or collet. you can put a flange on it to keep it from pushing backwards. Then, you want to split it down the length on one side with a band saw. Slip your pin into the bushing and then into the chuck. If the wall is extra heavy, you may need to cut into the opposite side of the bushing as well. Just don't cut it in half. I find that bronze will work pretty well for this sort of thing. The only concern I would have is vibration from the offset weight. Don't run it too fast. You may put a lot of wear on your spindle bearings.

Good Luck

Jim

If you use the same material the offset wont matter if you pu it all the way in the pot chuck. (no vibration) We did this all the time.

Depending on how accurate you need the offset, it could be done.

This little proggie would probably help:

"Need to turn an eccentric and don't have a four-jaw chuck (or don't want to set it up for a quick job)? Packing the work in the three-jaw will handle many jobs. This tool calculates the amount of packing needed. A more elegant method employing a slotted tube is also described along with a program for making the required calculations."

Thanks to Dan for the link.

Jim:

If there is a significant out of balance situation for any reason (odd shaped parts, eccentric turning, etc.), you might try to balance the load by using longer chuck jaw hold down bolts and clamping some weight under the bolts. They'd still hold the jaws fine. Got to watch for clearance of the added weight though.

That is 4 jaw chuck operation, unless you can "rig" something. Michael

you can adjust the jaws to get it close. I recently ran some square parts in my cnc lathe by placing the jaws in different positions on the serrations and got lucky enough to be in print!!

"D"

KEEP THE RPM'S DOWN !!!!!!!!!

:) "D"