[GreenKeys] Teletype motors...

[Kenneth Gartland]

Hi all!

Tom's advice shud be well heeded in regards to dismantling
and repair of these Teletype motors as found in the M14/15/20
models...

There are essentially two main makers of these motors,
namely GE and Holtzer Cabot...

When I was an "On the Job" trainee for Teletype eqpt many
years ago, the "Junior man" in the shop, me, was usually
stuck to repair & overhaul these motors on a continuing
basis...

They are not that difficult to work on, but as Tom pointed out,
one must have the proper Teletype bearing puller to get the
bearings off the rotor without damaging them!

We had a small length of iron pipe the exact diameter
match for the inner bearing race surface and a soft
surface hammer to tap them carefully back onto
the rotor shaft...

Most of these motors were in bad shape and needed
much work besides AC power lead replacement...

If you do decide to take one apart, be prepared to do
a complete cleanup, and bearing replacement while at it...

A Timken or SKF bearing dealer can match them up,
or some may be available from list members...

The easiest to repair is the familiar GE 5SH25AB11B

The Holtzer Cabot version is a bit harder to work on and parts
most likely unavailable now...

I didn't. mention the governed type, as there are several types,
but the same precautions shud be shown these as well...

Most of these are gone now, replaced by AC synchronous
versions...

Good luck on this, I wud try the heat shrink method of covering
the AC lead wires as far into the motor housing as possible,
before taking it apart...

If the motor runs quietly, and no signs of overheating,
bearings are probably OK!

If any signs of slow starting or rotor not spinning freely,
then bearings shud be suspect, also check for a condition
called "Varnishing" where the rotor shaft passes thru
the end bells...Fan end shud be checked also...
The varnishing effect is caused by a buildup of a yellow
colored "Crud" (Old oils, dirt etc) trapped inside the shaft
opening in the end bells...

Cheers!

Ken
VE3-HMQ
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