[GreenKeys] Model 20's and Oil

[George B. Hutchison]

The Model 20 selector is a 6-level variation of the pulling magnet 
selector found on earlier model 14 and and 15 equipment.

Properly adjusted the armature should never contact the pole pieces 
of the selector magnets.

Several times I have tendered my opinions of the various snake oils 
and potions available for lubricating things.

Amazingly, Bill Buzbee found that #10 non-detergent oil works!!!

The only time you want to use heavier than #10 in a selector is when 
the machine is in 24/7 service and housed in an insulated, 
noise-reducing box, allowing it to heat up to 140-150 degrees 
whereupon the oil will leave like will-o'-the-wisps in the vespers of 
the night.

The solution to high temperatures is a 50/50 by volume mixture of 30 
wt non-detergent oil and Andy Granatelli's STP oil additive. The oil 
will carry the STP into the mechanism and the STP will stay behind 
and lubricate while the oil turns to vapor and drifts away in the 
evening breeze.

The special treatment should be applied monthly. Less frequently 
applied there tends to be accelerated fret corrosion (where the metal 
turns into a fine red, dry powder that will mess up any clothing it 
touches) and you'll see your cam lobes and clutch teeth turning into 
little stacks of dark crimson powder underneath your machine.

W7TTY