I took some more pictures of the knee, the "star" knee drive
connection to the crank handle, and the gearmotor, this morning.

Here they are.

http://igor.chudov.com/projects/Brid...ntrol-to-Knee/

The motor is 3000 RPM, 65 volts. 5 amp continuous, 26 amps peak.

The gearbox is 1:15.

The best part of this gear motor, is that, I believe I just
discovered, its actual shaft is HOLLOW and is a hollow 20mm hole. The
piece with a sprocket on it is simply held inside the hollow gearbox
shaft, held by a cap screw on the opposite side. I will try to
ascertain this tonight.

If this is true -- I will check this tonight -- this is a major good
luck. The shaft for the crank handle is 5/8" (15.75mm), and so, I can
just make an adaptor with about 2.125mm thick walls, that will let the
gear motor slide on the shaft, have perfect engagement, and not "stick
out" too much. Then all I have to do to finish mounting the gearmotor,
is just to make a brace that will keep the gearmotor in place as
opposed to spinning on the shaft. The job of the motor is to be in one
place and spin the shaft, not to spin around it.

Mounting a limit switch and switch actuators should be an easy task
to, though like always it will probably take a long time.