[GreenKeys] Model 14 typing errors - lubrication problem? Misadjusted? Wrong selector magnet wiring?

[John Nagle]

   I have several Model 14 machines.  One of them mis-types
after a cold startup, but after typing the alphabet about
10-15 times, types without error.   If I stop the motor
for even two minutes, the errors come back, then disappear
after about three alphabets.

   Input is from a computer, so the sending end is probably
not the problem.  Loop current is measured at 57mA.

   The errors are semi-consistent.  Seen multiple times:

	B -> Z					11001 -> 10001	Drop 2
	2 -> hyphen				10011 -> 00011  Drop 2
	T -> some non-typing character		10000 -> ?

Seen once:

	L -> T					10010 -> 10000  Drop 2
	C -> N					01110 -> 00110  Drop 2
	E -> Z					00001 -> 10001  Drop 1
	$ -> 3					01001 -> 00001  Drop 2
	4 -> space?				01010 -> 00100  Drop 2
	R -> space?				01010 -> 00100  Drop 2
	8 -> space?				00110 -> 00100? Drop 4

So all errors are single-bit drops from MARK to SPACE.  So the
selector magnet isn't pulling in fast enough, or something is
binding.

I'm running this machine with the selector magnets in parallel, for
a resistance of 55 ohms. It came wired in series, for 220 ohms,
but I rewired it for 55 ohms like the other machines.

Selector magnet clearance is about 0.002, per spec.
Selector magnet spring tension is 150-200g, or about 6 oz.
The range finder is at 60, and will copy RYRY from about about
40 to 80.  Strangely, if, instead of data coming from the computer,
I send from the keyboard using a plain 60mA 120V power supply,
the range finder needs to be around 50.  I've looked at the
keyboard timing on a digital scope, and it looks correct,
but I may need to recheck that.

I'm using 5W-20 synthetic oil.  Room temperature is around 70,
so it shouldn't be too viscous.  Lithium grease has been used
on the grease points.  The whole machine (minus selector)

I have two other Model 14 machines and a Model 15, and
they don't have this problem.

Any ideas?

				John Nagle