I think that trying to use a craft knife based cutting machine to cut
piano rolls would be a complete waste of time [120803 MMDigest].  First,
it is unlikely to do a decent job at cutting the small holes needed.
Second, it will be very slow.  Third, it only works on mats that are
as long as 24 inches requiring many repositionings of the paper.

Then there would be the need to hack into the machine control to allow
it to cut patterns that it was never intended to cut.  These machines
subscribe to the "cheap razor" approach.  The machine is cheap but you
are supposed to buy "cartridges" to cut the shapes.  You would have to
hack into the basic X-Y-Z control system of the machine and I bet it
they will not make it easy.  Even if there is a control program that
does this for you, you are stuck with the three main problems listed
above.

If you already have one of these machines it might be fun to try to
get it to cut a roll but you will almost certainly loose interest after
spending hours to make one sloppy roll.  I have watched high quality
CNC film cutters in operation and even they are very slow for intricate
patterns.

Best regards,
Spencer Chase
Garberville, California
http://www.spencerserolls.com/