Suction Unit Plays Piano Too Loudly
By Richard Moody
A client has a vacuum motor installed in her Gulbransen player. It
appears to be made for player pianos, i.e., it's in a square box of
particle board that looks like what Lee uses. Printed on the box is
25 Hz - 60 Hz
PAS v(?) High
3.8 amps 112 volts
Can I put a dimmer switch on this motor?
The problem is it goes full tilt (the suction is 55 inches), making
the piano very loud and in re-roll it goes way too fast. The previous
"repair person" rigged up two squeezed tubes (tracker bar size) that
seem to choke off the vacuum but this causes the motor to labor. This
must be how Gulbransen handled re-roll speed as the tubes are connected
to a Y and that goes into the box that appears to contain the stack
vacuum shutoff, but it cannot deal with 55 inches suction.
Choking the vacuum doesn't make any sense to me but blocking these
two tubes completely seem to "choke" the vacuum until the motor really
labors and the re-roll seems to be "locked down".
Also, this piano has the Gulbransen fish pole tracker that kind of
works. I wonder if a manual is out there that explains the adjustments?
I didn't see adjustment procedures in the MMD Archives.
Thanks for any advice,
(Message sent Sat 5 Jun 2010, 18:16:48 GMT, from time zone GMT-0500.)