Ampico B Roll Drive Motor Is Weak
By Robbie Rhodes
[ Ref. 150429 MMDigest, Ampico B Reroll Brake Adjustment --
Lester Wolff wrote in 150429 MMDigest:
> The music roll stops when the snubber is activated but it
> does not continue to reroll unless momentarily hand assisted.
The problem can result from an ailing roll drive motor that
no longer develops the torque that it did when new. Check:
1. The brushes should slide freely in the holder.
2. The pot metal brush holders may be warped.
3. The points should be smooth and slightly rounded.
4. The resistance of the wirewound resistor that shunts the
points should be about 360 ohms.
5. Check all the soldered connections.
6. Check that the proper tap (25 ohms) is connected on the big
tapped resistor for the roll drive motor.
MMD articles on this topic are indexed at
Search within for "Ampico B Roll Drive Motor" and "Ampico B Spool Motor"
(Message sent Fri 1 May 2015, 22:10:33 GMT, from time zone GMT-0700.)