Newsgroups: rec.crafts.metalworking
Subject: Re: How to remove stuck chuck from 13 inch SB lathe spindle
From: Robert Bastow <"teenut"@ hotmail.com>
Date: Fri, 21 Jan 2000 16:23:25 GMT

BURN the Bugger off!!

Seriously though you are fortunate to know that it is stuck by reason of shock
over-torquing and not because it is rusted or ill-fitted.

Here's what to do.

Get a six inch or so length of the largest hexagon bar that will fit thorough
the chuck center and grip it tightly in the chuck with a couple of inches
protruding.

Place a ring wrench of the correct size on the hex and TIE it there with  Duct
tape..this is to stop it flying off.

Clamp a length of two x four lumber on the lathe bed at the point where the
wrench will impact it.

With the lathe in the lowest high range gear..not back gear!! and the wrench
pushed as far clockwise as it will go quickly HEAT the back plate boss with a
concentrated torch flame.  This need only be hand hot..the boss will expand
minutely while the spindle remains cooler..insulated by the oil and air gap.

Now, GENTLY jog the starter button..so that the chuck turns over smartly..but
NOT under power..to impact the improvised stop.

A couple of such "taps" should shock it loose.

Been there..Done that!!

teenut



fdander@attglobal.net wrote:
> 
> HELP! When I momentarily bumped my 13 inch SB lathe in reverse, the  6-inch
> chuck with threaded backplate began to unwind.  To avoid a nasty
> disengagement and free-fall onto the lathe bed, I instantly reversed the
> switch to FORWARD before it reached the end of the threaded portion.  Big
> mistake - under power the chuck screwed itself back on with a  vengence, and
> now it remains stuck. A 36 inch cheater doesn't move it off ( I estimate
> about 150 foot-pounds of torque).  Spindle nose thread is 2-1/4 x 8.  Any
> ideas?   Thanx, Dave