xray wrote:
I have a Jacobs 14N 1/2" chuck for the tailstock of my lathe. The MT2
arbor it is mounted on has spun in some past life and is a bit munged
up.

I ordered a new JT3 to MT2 arbor for it, but now I find I can't budge
the existing arbor out of the chuck. It's not rusty. I've soaked it
penetrating oil for about a day. I tried heating it with a torch and
then later by baking it in the oven. Quickly cooled the arbor with a wet
sponge while the chuck was still several hundred degrees from the oven.
I've succeded in slightly bending a Starrett center punch trying to
pound the arbor through the center hole in the chuck.

Any tips on things I could try to break up this long-term relationship?


I ran into exactly that same problem a few months back. Like yours,
there was no shoulder to bear wedges against. I did the hammer and punch
thing, the soak in penatrant & bigger hammer and another punch (the
first one started to bend) trick, and finally the hardened steel pin and
10 ton press trick. None budged the chuck. In frustration, and figuring
the chuck may be lost anyhow, I cut the arbor off flush, chucked the
chuck in my lathe and drilled and then began carefully boring out the
remains. I tried to approach slowly, hoping that I could cut into what
was left of the arbor thin enough to collapse with a chisel, without
hitting the chuck. As I apporached what i thought would be close enough,
I noticed that there was a pattern in the bore. A close look revealed
that the end of the arbor was THREADED! Duh. Color me stupid. Not sure
why that possibility never occured to me, but my excuse was that I did
not put the chuck on there, so i couldn't have known. A few taps with a
chisel and what remained of the arbor easily unscrewed. So if you did
not put that chuck on there yourself, you may want to double check...



-AL A.