On 2018-09-09 14:19, Dimitrij Klingbeil wrote:
On 2018-09-08 18:27, Bob Engelhardt wrote:
On 9/7/2018 6:20 PM, Bob Engelhardt wrote: [...]
The windings at the back of the commutator are wrapped in string
& coated. I'm thinking that I can cut back the string & get at
the winding.

With a small bit in a Dremel I excavated behind the segment, down
to its connecting wire. There was no continuity from that wire to
other segments! Then I noticed what had been staring me in the
face all along - the connecting wire exposed and broken:
https://imgur.com/a/jhIcgqf

Its connection to the segment also came loose, so I soldered in a
jumper: https://imgur.com/a/yiBcCit

It surprised me that the original connecting wire was steel. I
don't know why steel would be used, but it made soldering
difficult.

Congrats! Now that the connection is done, make sure to touch up the
worked area with epoxy to protect it from vibration and from being
sandblasted. Since it's going back into a drill and drilling dust is
highly abrasive at typical rotor velocities, neither the wire nor
the soldering should be exposed. The epoxy coating should be made
smooth so that the "bump" over the rework does not stick out too much
into the air and dust stream. When applying epoxy, try not to leave
any unfilled air pockets underneath as far as practical.

P.S. From the picture it looks like a neighboring wire lead is exposed
and already partially abraded down. Make sure to re-protect it as well.