The discussions about tracker systems on MMD lately got me thinking
about a very unusual one I saw a few weeks ago.  I was visiting Don
Neilson and thoroughly enjoying his marvelous collection of pianos and
organs.  He showed me a rather unprepossessing Standard nickelodeon
built by the Standard Player Piano Co. in Oregon, Illinois (no relation
to the Standard Pneumatic Action Co.).

Standard Player was an early manufacturer of coin-operated pianos
and most of them (including this one) used an endless roll mechanism
mounted on the back of the piano.  Don dropped a nickel in this piano
and it played very nicely.  While watching the roll transport mechanism
I was surprised to see that it had an automatic tracking system, and
I've never seen an automatic tracker on an endless roll mechanism
before.

This one was devilishly clever.  The tracker bar was mounted face up
and the roll was pulled up out of a bin underneath, over a wooden
infeed roller, across the trackerbar, through pinch rollers, and then
back into the bin -- nothing unusual about that.  The tracker bar had
a slot cut in each end, and located in the slots were two adjustable
tracker holes.  By turning a knob the holes would move in toward the
center of the tracker bar or out.

You'd adjust the tracker holes until they were close to the edges
of the roll.  Each hole was connected to a valve which was in turn
connected to a small pneumatic which in turn was arranged to lift
either the right or left bearing of the wooden infeed roller about
1/8 inch.  Lifting one end of the roller would cause the paper to shift
sideways (I can't remember if the paper would move toward or away from
the raised end of the roller but move it did).

It was neat to watch the ends of the roller being raised up and down as
the roll tried to wander, and the result was almost perfect tracking.

Mike Kitner