Bob Pinsker wrote:

> I guess one of the advantages of this type of motor is that when the
> coil is not powered, a spring pushes the rotor out of the laminations,
> thus neatly disconnecting the rotor from the gear train and freeing
> the roll take-up from the motor for rewinding.

This reminds me: the exact same auto-clutching system is used in
pinball machines, on the motor that rotates the cam sequencers to
compute the score for hitting various targets with the ball.  These
mechanisms have not been used in pinball machines since 1978, but there
is a company in Wisconsin, I believe, that can replace any pinball
motor.  My guess is they could help you out greatly.  Unfortunately
I can't remember their name,  and I'm leaving early tomorrow morning
on 2 weeks' vacation.

You could post on rec.games.pinball and ask.  One caveat is that
pinball motors are not variable speed, but that shouldn't matter much.
They have that open laminated frame with the coil on one side and the
little shifting armature on the other.

Mike Knudsen