I have found some time to work on my software to drive a laser piano
roll cutting machine that anyone can build using a hobby-type laser
engraving machine or something more robust.

The machine that I hacked for testing is no longer available so I will
not be able to provide exact instruction as to how to build a machine
like mine but it is not terribly difficult for the hobbyist who has
fairly advanced skills. I can provide pictures that show how my machine
was constructed.

I was lucky enough to buy a machine that lent itself to modification.
Today's machines are bit more difficult to modify and it might make more
sense to start with basic components instead. These are available from
sources catering to the DIY 3D printer hobbyist. A lot of information
is available open sourced.

My program now accepts as input "punch MIDI" files conforming to the
standards set by Warren Trachtman several years ago and supported by
the editing software that Julian Dyer has made available to the public.
It has been a long road figuring out how to make the conversion from
MIDI to G-code to drive a GRBL-based CNC machine but it seems that
I have gotten most of the details right and that the rest can be
figured out, hopefully with the assistance of at least a few Beta
testers.

My program is very versatile and will allow for a variety of options
such as different hole sizes for each track, offsets from the punch
line, all sorts of horizontal spacing of holes, trimming of sheet to
match holes and numerous other features. Default setting are included
with the program but all configuration settings are user changeable and
can be saved in configuration files of which there can be any number.

If it looks like several people will be using the software I will
add additional features such as leader trimming and other customizing
abilities. I have tested to the point of showing very reasonable
emulations of G-code that look exactly like piano rolls. The next
step in testing is to cut some paper and see how it matches the
original rolls that were scanned and converted into punch MIDIs.
I hope to do this very soon.

If there is enough interest I might be motivated to make an option to
create G-code files based on pages that can be cut on a standard laser
engraving machine without modification. This will be a considerable
task and would result in a system that would be easy to implement but
would not be very efficient.

Paging by hand would be necessary so it could not be run without an
operator in full-time attendance. The only reason to do this would be
to prove the concept and I am hopeful that anyone interested in this
project would build a dedicated machine that could be run unattended
and that this approach would not be necesary.

I have a few people on my "interested" list and will add anyone else
who is interested. I will provide the test program to anyone who is
willing to test it and provide feedback. It will require becoming
familiar with making punch MIDIs and with viewing the simulations.
I can provide some punch MIDI files just to prove that the program
works.

Figuring out how to create various types of rolls will be left to
the experimenter and I will not provide support in this respect
or in  teaching how to use the necessary programs from Warren or
Julian. This will be the responsibility of the user. My program has
a reasonable help file but that is the limit to my support. Anyone
who is willing to build a suitable machine is welcome to a higher
level of support.

It was a huge effort to write and test this software and I am not going
to spend more time supporting those who do not take it seriously.
If you are seriously interested contact me through the email address
associated with this posting. If you are only interested in discussing
the theoretical or finding another ways of wasting my time please
refrain from contact.

Spencer Chase
Garberville, California
http://www.spencerserolls.com/ 
spencer@poodlex.com.geentroep [delete ".geentroep" to reply]

[ A "punch MIDI" file contains the all the data necessary to configure
[ and control a machine that makes a hole in a thin medium such as
[ cardboard or paper. The method can be punch-and-die, electrical
[ discharge machining (EDM, spark machining) or laser beam machining
[ (LBM). -- Robbie