On May 18, 11:34*pm, "Michael Koblic" wrote:
...
Revisiting the shaft affair, what should one have done? The profile is
round, not flat. Would you apply the lapping compound to the bushings and
spin the shaft in them? Would the bushings still be useable afterwards?
Should one have a set of "lapper bushings"?

Michael Koblic,

High-speed internal grinding attachments for lathes were once made
with extremely close hardened steel-on-steel bearings without oil that
reportedly would coast for a long time although they seemed to stick a
little at rest. They were fitted by lapping with fine diamond dust,
which didn't embed in the steel. I think I saw that in one of Fred
Colvin's books.

I fit pressed-in bronze bearings with a reamer and make slight changes
to the drag with an adjustable reamer. Mine are mostly the cheap
imports and they begin to chatter if asked to remove more than a hair.

I've read that a half-round or D reamers works well and you can make
one to any size on your lathe.

jsw