Jet 16-42-2 help

[Paul Kennedy]

I noticed that when I put any of my chucks onto my lathe they don't run true. I check the threads and found some damage. I am unsure how i caused the damage. Is there a fix or do I need to replace the shaft? Thanks, pkennedy

[charlie knighton]

how long have you had lathe and chucks???????? some pictures of spindle threads would be nice.

[Russell Neyman]

Several comments:

One, insert your Jacob's chuck into the shaft and turn the lathe on at low rpm. If that wobbles it's your shaft: if it doesn't it's either the chuck or the threads.

If you tighten the chuck COMPLETELY and are sure it's completely seated that will overcome most problems.

Except for spindle work, a misaligned chuck, etc won't be a problem since the axis is only relative to the object being turned. As long as you don't unmount/remount it things wills always be true.

[Kyle Iwamoto]

What brand of chuck? If you have a Nova chuck with a different brand adapter, it's a known problem that they may not run true. You need to buy Nova adapters for the Nova chucks.
Also if you use that plastic washer, that can cause problems too.
How did you bugger up the threads? Pictures would sure help. The spindle metal is pretty soft. IF you know what you're doing a triangle file can do wonders.

[Jeffrey J Smith]

As Kyle pointed out - chuck adapters can be a problem. If you've got OneWay chucks, a former rep told us during a demo that it's a good idea to check that the adapter is tightly seated and the screws tight. He used two chucks, tapping them together, adapter to adapter to seat them then was able to tighten the screws more than anyone in the audience could believe. That was on a couple of chucks that had been in service for a few years.
I did have a 1642 for a few years and found the spindle to be incredibly soft. It's relatively easy to damage the threads. It's also relatively easy to file them back into shape - or use a die to get them back. DAMHIK.
Even with the soft, unhardened spindle, if you somehow had an incident that caused the shaft to bend, I'm guessing you'd remember exactly what may have happened...

[Paul Kennedy]

Thanks everyone for your replies. Concerning the chuck inserts, I tried 5 different chucks with the same result. A friend suggested I put a dial indicator on the spindle and check for run-out. That is my next step. Thanks again, pkennedy