[R-390] Autotuners

[Bill Hawkins]

Barry Hauser wrote,

"The worm drive goes through several sintered bronze Oilite bearings.  These
are porous bronze bushings that were permanently lubricated.  But,
"permanent" generally assumes for the "life of the tool" or whatever, not
necessarily 50 years going on another 50.  Those bearings were pre-soaked in
a special lubricant -- but I don't know what."

Sintered bronze is porous, but you can't relube it by soaking. You need to
pull a vacuum on it while it sits in a jar of light oil. But first you have
to clean the old, gummy oil from the pores with the usual solvents and
vacuum, then heat to evaporate the solvent.

OTOH, soaking the bearing in solvent, heating it a bit (no smoke!) and then
soaking it in, say, 3-in-1 oil will work for a while. The problem with
soaking
in air is that the air in the pores is not displaced, so not much can soak
in.

Regards,
Bill Hawkins