I don't think it's near as easy as it may seem, at least beyond test samples. When manufacturing film, you want to be especially careful that the punched chips (all of them) are completely removed. And that the perforations are clean, with no ragged edges or broken chips laying near the edge. Anything left behind has the potential of ending up in a good frame during the exposure. Or remaining trapped in the edge of the film gate for the rest of the roll.
Originally Posted by AgX
In order to punch clean perforations, the punch and die set needs to have a certain clearance, which depends on how the film base shears. And if it is to be a commercial product, the perfs ought to conform to the ANSI/ISO standards for size and spacing, etc. I can probably dig up some of these dimensions (older ANSI specs), if anyone needs them.
A machinist who maintained some of this gear for a manufacturer once explained some of the difficulties to me; some extraordinary precision is called for. (I wonder if any of the perfing machines showed up in the book, Making Kodak Film.)