Hi, Super technical question here :-)

Can any of you perforator owners please educate me on the workings of
the paper advance (stepper motor) mechanism? I do know this is a
critical part of a roll perforator, that has to be working exactly
right for the rolls to be in time.

I have always thought that a perforator could be built and driven
directly by the Cakewalk pro audio program if the MIDI clock output
could directly drive the stepper motor. Cakewalk advances 24 steps per
beat, so the perforator must follow exactly, if the motor was synched
with the time base.

I believe that the note punches can be directly driven with solenoids,
reacting from MIDI out with a MIDI driver board. It would take some
experimenting to translate how many clock pluses=punches, (duration's)
but once that was mastered, I would have no trouble. The recording
piano I developed enables me to have precise control over that.

The end result of this project is that I would like to directly operate
a perforator from the same computer that is installed in the step
piano. This will be the most challenging part of this four year
project.

I have had no luck locating a old punch ram and punches to rebuild, so
in all likelihood, I will have to have a machinist build a new one from
scratch. I was hoping I could find an assembly from a basket case
perforator, but no luck as of yet.

If you would like to see the recording piano I built please look at

    http://mmd.foxtail.com/Pictures/StepPiano/taylor_step_piano.html

I apologize that the finish on the piano looks so bad. It's a
workhorse, so I gave it new strings and hammers, but left the old ugly
finish alone. I may refinish it later. This is basically a electronic
version of the "stop type" arranging piano that J Lawrence Cook used
at QRS...

I also have the very first MIDI file I recorded from this machine. If
you would like a copy for your review, please write me and I will send
it.

Andy Taylor
Tempola Music Rolls.

 [ Andy,
 [   I helped David Wasson operate his perforator synchronously.
 [ In David's case, the perforator is driven by an AC induction
 [ motor, so there's little that can be done to control it.  What
 [ he did was to put a cam operated Microswitch onto the perforator
 [ mainshaft.  The Microswitch drives an input on a Devtronix
 [ input board.  The Devtronix board generates a MIDI "real-time"
 [ "time event" (0x7e) which is sent to the MIDI interface.  The
 [ MIDI interface is set to operate synchronously with the MIDI
 [ time events.  It works perfectly.  In fact, with a program I
 [ wrote for him he gets really beautiful and reproducible chain
 [ perforations.  Because the data value of the "time event"
 [ is 01111110, it should be possible to generate this with a
 [ "one-shot" -- i.e. you wouldn't even need the Devtronix board.
 [ -- Jody