Norm Dresner wrote:

I finally removed the chuck from the spindle on my circa 1973 AMT 1/2" bench
drill press -- the one that has been the subject of several threads
including one that concluded that I was absolutely crazy for believing a
nameplate that said it has a JT#2-1/2 spindle.

Nobody thought you were crazy. The reaction you posted to the first
question, though...


Well, here are the measurements -- along with specifications I've gotten
from the web

JT# Large Dia Small Dia Length
#2 .5590" .4876" .8750"
#2short .5488" .4876" .7500"
#2-1/2 .677" .625" 1.055" --- my AMT
#3 .8100" .7461" 1.2188

It's also not anything close to any Morse taper either, nor a B+S.

I guess it really is a JT#2-1/2 and nothing else.

Which means that there's no way that I can replace the chuck with anything
better today.

Given that there are milling machines out there (new, not high end
though) that would be hard pressed to keep to the runouts you are
reporting, most of us would not bother, methinks.

Also, in removing the chuck, I discovered that the set screw that holds the
pulley to the shaft was missing so all speeds under load were slower than I
thought they were. I doubt that this had any effect on the runout, but I
will measure it after replacing the chuck just to make sure that I haven't
made it worse.

Did you remove the arbor from the drill press? If it IS an MT2 arbor,
as the tag said, then ...they are not too expensive to consider just
buying a chuck and arbor that match. The arbor would run $20 and the
chuck the better part of $200 for new top of the line stuff at retail
(estimating).

Cheers
Trevor Jones


Norm