[ Ref. 160506 MMDigest, Homebuilt Piano Roll Punch

I read Mark Williams comments about making a perforator and would
offer some small advice.  I speak from experience as I made a working
perforator, based on Richard Tonnesen's design.  Richard's machine is
robust, now living with Ed Gaida, and it has been functioning for about
36 years or more.

 [ See http://www.mmdigest.com/Gallery/Pictures/tonnesen.html  -- Robbie

First: put aside about $5000 to $8000 for the machine work necessary.
Despite working several years as a machinist, I needed a vertical
milling machine to make the punch guide bar, the die and die backing
plate, plus the offsets for the crankshaft, which moves the punch head
in and out of the die.  Then you have to design and make a frame to
hold all the pieces (10 banks of 10 solenoids per bank that pull the
interposer bars).  Then there is the design of the paper pulling
assembly.

The punches themselves are stock items, available in .0005" increments
from Ross Punch (or any other company that makes plastic ejection
molding pins will do).

Another question to answer is about the number of copies you plan to
punch at a time: making one copy is easier than making 8 or 16 copies
at a time.  There are also other issues that arise as the design comes
together, so be prepared.

I considered driving the punches directly from the solenoids, but
there was not enough room to squeeze everything into the space
available.  Perhaps someone more clever than I can solve that problem.

I spent about five years (part time) designing, troubleshooting and
fabricating the grand assembly but lost interest, with the arrival of
e-roll players and MIDI files on the scene.

I encourage you, Mark, but do a lot of homework, talk to others that
have been down the road, and then do your design.  It's not difficult,
just long and tedious, kinda like rebuilding a player piano -- lots
of detail work.

I was looking for some photos I had of my machine, but I can't find
them now.  I'll keep looking and send them to you when they surface.

Good luck!

John McClelland
New Mexico