Subject: How to straighten a shaft?

From: [email-masked]
Date: 23 Feb 94 11:56:38 PST

I just acquired a nice 10" rotary table at a good price.
It is unused, but has a problem: the handwheel shaft is
slightly bent.   While it is usable, the wobble is very
unsightly and it prevents disassembly.   (A long eccentric
bushing must be removed from the shaft before the shaft
can be extracted.)

I would appreciate any hints on how to straighten this
shaft without destroying anything.   It is about 5/8"
diameter and I have about 1.5" of it to play with.
I would guess that the wobble at 1.5" is about .05"

--  Alan E. Frisbie               [email-masked]
--  Flying Disk Systems, Inc.
--  4759 Round Top Drive          (213) 256-2575 (voice)
--  Los Angeles, CA 90065         (213) 258-3585 (FAX)

---

From: [email-masked]
Date: Sat, 5 Mar 94 09:26:38 -0500

Alan. I had to do exactly the same thing in a 9" Troyke table I bought,
very used, recently. It had been set down hard on the handle as was
probably yours. The bend is likely right at the bushing. What I did, which
worked, was take the worm shaft out by removing the cam bolt. Put the
shaft in your lathe with the 'handle' part in a collet or centered in
your 4-jaw such that the bend is right in front of the jaws. You'll find
a place out by the worm that you can indicate. Get a pipe with an ID a
bit bigger than the worm OD, wrap some rubber around the worm to protect
it, insert the pipe about halfway down the shaft, and smoothly apply
pressure to the shaft. Then indicate the shaft periodically to check
progress. That .005 bend will translate into something pretty big out
by the worm and when you get the shaft out by the worm true to a couple
of thou, you'll be in business. The problem is the degree index collar
bumps as it goes around if the shaft is bent (right?) and doing this
will allow it to not do that. So long as the bend in the shaft is sitting
right at the end of the chuck/collet jaws, that is where the shaft will
again bend. I hope this makes sense. It's fairly scary but was recommended
by my friend Roland (the guy at the NAMES show with the Bentley BR2
rotary engine -- the guy who actually built one, not the guy who farmed
it out), and it worked fine. It is scary I'll admit. But it worked.
 
Charlie