>[ Ed says he averages 6 feet per hour punching the 20er organ rolls; ...
>[ Maybe I should make a MIDster to perforate 75-note Wurlitzer 165
>[ rolls. Of course, it would probably run about one-quarter as fast
>[ as when punching 20-note music.
In practice a lot depends upon the type of music and its format. Heavy
pieces with many chords of five or six notes will always take longer to
punch than simple melodic airs. Wurly 75 note music would tend to have
more notes in play simultaneously than 20 note music, as would 88 note
piano music. Also there is the extra distance that the punch head(s)
must travel across the wider paper.
My own prototype MIDster Punch machine uses a screw thread to traverse
the single punch head across the paper. This makes it quite slow in
operation, but of course I can just leave it to punch and do some thing
As a rough guide, it takes my own machine about 4 hours to punch a
four-minute song in Raffin 20-note format. As the finished music
plays at 70 mm per second, I calculate (counting on my fingers and
toes!) that it punches at a rate of almost 14 feet an hour. I might
be able to increase the maximum programmable stepping speed of the
motors a bit by increasing the drive voltage, but I have not yet found
the need to do this.
On the other hand, Peter Hood, a MIDster Punch builder in Kent,
England, has built a superbly crafted machine driven with a toothed
belt instead of a screw thread, and which also incorporates my
two-punch-head modification. He produces a similar song in John Smith
20-note format in about 25 minutes, which is something like 120 feet
per hour! Peter has plans to supply punched John Smith music rolls
commercially quite shortly. He regards it as a growing market need
which he hopes to address. I have a videotape of his earlier,
single-head machine, in action, which punches amazingly quickly. He
has promised to send me a picture of his two-headed punch very soon.
So the answer is: MIDster punching speeds can be anything from very
slow to very fast. There are a number of variables which determine
speed: the music density, the format, the paper width, the number of
punch heads and the drive-system of the machine you build. The main
thing is that if you leave the machine going while you sleep, you might
never need to know how long it takes!
[ Thanks for the data, Bob. Any method is better than
[ chopping the paper with a hand punch and mallet! -- Robbie