[ On 970421 Mike Knudsen asked about adjusting his "Gem" Roller Organ

Mike Knudsen,

I'm not an expert, but I'll share my experiences:
You are correct in assessing that there is no intended adjustment on the
Gem. The worm gear is crimped onto the shaft, the trip pin is forced
through a hole, and the drive flange and pin is keyed on the shaft. So ...

The position of the worm gear on the shaft would probably not affect the
tripping rotation, but would instead affect the horizontal alignment of the
roller. By your description, dismiss this option.

The trip pin should be roughly opposite the drive flange pin. Is it
possible that the trip pin is inserted in the wrong direction? This would
cause the mechanism to trip _exactly_ one half turn early (or late). This
would also be the easiest to fix--remove and reinsert the pin.

Or, is the drive flange rotated on the shaft by having sheared the "key"
protrusion (which may have broken off of the softer metal hub)? If so,
you'll have to repair the hub, or replace the "key" protrusion with
something like a pin for alignment. A messier job.

Good luck!

- Todd Augsburger,
  Kenton, OH