Organ blower modification

Christ Memorial Church, Williston, Vermont, USA

The old Spencer 1/2HP "Century" motor was causing continual starting
trouble because the brush assembly would not reliably pull away from
the radial commutator at the back of the motor. The brush assembly would
sit there, half engaged, generating much light and ozone, with the motor
running half speed and the organist wondering why everything was out of
tune. After many attempts to clean the unit and adjust the spring loading,
I finally decided to replace the motor. Because there are no motors available
with a 16 inch shaft, I constructed a pulley-driven jackshaft assembly that
uses a much smaller 3/4HP furnace blower motor.

Original motor and blower

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New motor assembly

Same bolt pattern, shaft location, shaft length as Century motor.
Yes, it's belt-driven. However, this is not considered a long-term
maintenance problem if the curator happens to be sitting in the pew
every Sunday morning!

Motor, pulleys, pillow blocks, and jackshaft are from Grainger.
Threaded rod and steel plate were from my inventory.

Looking back, the only problem we've had in the three or four years of
operation has been a loose pulley setscrew. Using a second setscrew
on top of the first one would serve to lock it in place. If I get a spare
week one day, I'll do that!

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