John Phillips asks about the rewind pneumatic [131108 MMDigest].
I don't have a Steck as John describes but I do have a Autopiano-
based Recordo with re-roll, forward, and power shut-off functions.
Since John has no forward function he doesn't need the logic to
maintain the power at 'end of re-roll' as is needed for the
'forward' function

My Autopiano has three pneumatics: two are placed as John describes
and a third pneumatic is placed on the back end of the valve block.
The trapezoidal arrangement is done presumably to enhance the force
generation at the instant of energising the pneumatic.

In Art Reblitz's book, he comments that these pneumatics seem to be
under-powered (see page 185).  By angling the pneumatics in this way,
the force development is at its greatest.

Paul Rumpf
Melbourne, Australia