Jeffrey, The Autopiano player action uses a 4-hole arrangement in
the tracker bar -- two on each side with one set outside the other and
slightly higher (or lower) than the inner pair. The tracking system is
designed to accommodate the earlier paper width as well as what became
standard.
There is a tricky valve block between the two tracker pneumatics that
shifts the roll based on four vacuum signals from the tracker bar.
For one paper width, both pneumatics have vacuum when the paper is
centered and one or the other gets vented to atmosphere. Thus they
are fighting each other, but balanced when the paper is centered.
For the other width, they are both vented when the paper is centered
and one or the other gets vacuum to bring it back to center. For the
narrow paper, both outside holes are uncovered with the paper centered.
With that in mind, experimentation with the four tubing connections
will eventually get you there, assuming that the valving inside the
tracker system valve block is okay.
Hint: identify the four tubes as A, B, C and D and make note of tried
sequences of connection. You can probably find more information on the
Autopiano player action, but of course it may not apply to the one you
are working on. You may find that Autopiano made your action.
Bill McKeown
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