I have a Smithy 1220 lathe/mill and was turning a 3/16" threaded coupler
down yesterday and I noticed that there is apparently a taper in it.
The end away from the chuck is about .006 wider than the end near the
chuck. There is no adjustment on the headstock as far as I can tell.
I'm going to call Smithy Tuesday but I was hoping some of you
knowledgible folks could come up with a solution. It's really wierd.
What I'm doing is turning the couplings down to be pressed/glued into
the center of a couple of cocobolo shift knobs I made for my Jeep. I
need to have them pretty much straight. thanks.

Jim