Marvin Horovitz wrote in 100720 MMDigest:

> My Tangley calliope roll drive has an AC motor that runs fast.
> I do not want to change the pulley and belt.  I would rather use
> a variable speed AC motor controller.  What AC motor controller
> would solve this problem? ... Some of the rolls may be punched
> at the wrong tempo.

If the calliope is fitted with a roll frame with a built-in bevel
gear (Tangley) or a worm gear speed reducer (e.g., Coinola), the best
variable speed electric drive for it is a DC motor with a companion
regulated variable speed controller.  This system will pull the music
roll at any speed wanted without overheating.  (AC motors and stepper
motors are likely to overheat inside the confined compartment of
a Tangley calliope.)  For example, search for Bodine DC motors at
Minarik Electric, http://www.minarik.com/ 

Robbie Rhodes
Etiwanda, Calif.