As a past tool and die designer, perhaps I can put some input into this
roll perforator discussion.  I have never made one myself, but I have
thought about it and have seen a couple in operation (Ed F---, and       )

Making a punch, die, and stripper plate for a moving carriage assembly
should not be too difficult.  Now, the only mechanical problem I see is
the same problem which affected my industry when I was working for a
living (I am a college prof. now).  Sometimes, due to oil film on the
punch or suction, a slug (the part punched out if it was scrap) would
come up out of the die and lay part way over the hole.  Then, when the
stock was moved, the punch would have to pierce two thicknesses of
material (steel or aluminum in my industry).  Not so bad if it does not
happen too often, but very bad if the punch if forced to pierce two
thickness of material on one side and one thickness on the other side.
Because of punch to die clearances, the punch could deflect and nick
the edge of the die.  A nicked die creates a hughmongus burr.  The die
would then be taken out for sharpening.

The simple perforator would probably be required to partially punch a
hole.  In other words, little mezza-luna (half-moon) shaped slugs would
be the result.  A sturdy, well-supported punch can handle that.  But
what does one do with all the partial slugs coming up with the punch?
That is a problem to be solved.

Due to the very close clearances required for paper (about 5% the paper
thickness), any punchings which may come up may have the ability to
deflect the punch.

This may or may not be a problem or it may be easily solved by you.

Interesting idea, keep thinking about it.

Andy LaTorre¶
LaTorre Orgue Mecanique