[GreenKeys] Model 14 tape printer repairs, parts, etc.

[David Burns]

With respect to the intermittently non-starting synchronous motor, I was 
given (what I regard as) pretty good advice by my brother-in-law should 
you decide to open the motor (which I've done, but /after/ receiving his 
advice!).

The clamshell ends of the motor are held in place by two long screws 
that go all the way through the motor.  Naively one thinks "Well, I'll 
just unbolt those screws and the ends will pop off".

Not so much.

Each end of the armature has the ball-bearing race press-fitted onto the 
end of the armature shaft...no surprise, and unless something is 
terribly wrong, prying the clamshell end off either end of the motor 
leaves the ball bearing race in place -on the shaft-  (watch out for the 
spring-loaded grease clamp that surrounds the outermost end of the 
race).   In effect, one is prying the race out of a press-fit into the 
clamshell.

This is what I did.  I had to pry it off with a screwdriver (after 
removing the bolts).

My brother-in-law's advice: Mark each clamshell (against the main motor 
housing) to indicate the /exact/ rotational correspondence between the 
clam shell and the motor!  A small scratch in the paint across the 
divide between the clamshell and the main motor housing should do the 
trick, before you unbolt the clamshells.

In this manner, when you finally come to struggle to put the thing back 
together (without the factory jig that no doubt made such an operation a 
snap), you can re-align each end, do the press fit to cram the bearing 
race into each clamshell so that the screws pass through the motor 
linearly without zigging or zagging.

I haven't finished...my motor is in pieces.  Good luck!

-Dave in Boston

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mailman.qth.net/pipermail/greenkeys/attachments/20120725/7cfab293/attachment.html