Simple Roll Punch
By Andy Latorre
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 |
(Message sent Mon 21 Oct 1996, 15:05:52 GMT, from time zone GMT-0500.) |
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