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This is my first time posting to this list, and have enjoyed reading it
and gaining lots of useful information from it. We're in the process
of restoring a paper-roll Decap dance organ. It has two Celeste ranks
of string pipes at 8' and 4', and two ranks (also at unison and octave)
of jazz flutes for pipes in the melody as well as an accordion. The
accompaniment is a single rank of viol/cello pipes, and the bass is a
stopped flute that doubles up by borrowing notes off the accompaniment.
This was nearly a 'basket case' when we got it; it was missing the
original motor (probably 220v 50 Hz) and one of the pulleys acting as
intermediaries between the motor and pump crankshaft pulley. The pump
is of a type that pumps both vacuum and pressure, having two sets of
rocking double bellows that feed or draw into separate reservoirs
(rather small, in my opinion, especially the pressure reservoir) for
the playing action or pipework.
My question is this: how many revolutions per minute (rpm) is the
crankshaft on the pump on one of these instruments supposed to turn at?
We've tried several different pulley sizes, and the pump doesn't
generate enough wind, even though the chests are recently rebuilt and
tight.
John
email: jrunge(at)together(dot)net
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