My film slitter

I have been asked to show some pictures of my film slitter, so here goes.

THE BASE

The base is based on a splitter I saw on the Sub Club (http://www.subclub.org/darkroom/splitter.htm) , but the cutting blade arrangement didn’t allow for splitting film for more than one format.

The film channel is constructed to hold the 35mm film straight and the supply cartridge is held straight by the felt light trap. The take up cartridge is held straight by the end pieces added on each side of the metal bracket.

Note the hole for the slotted drive tool in the left hand side plate.

THE SLITTING HEAD

I used the blade spacing method devised by Ron Pedalty (http://ronp.freeyellow.com/slitter.htm). The blades are snap-off hobby knife blades set into 5/32 inch brass tubing, which has been flattened and inserted into epoxy. The difference is that I drilled holes into the oak wood at approximately the correct spacing and then adjusted as the epoxy hardened.

Minox film slitting head - - - - - - - - - - - 16 mm film slitting head

The block to hold the blades is cut to fit the film channel as exactly as possible. I used a small piece of square plastic tubing to help hold the film flat for cutting. It doesn’t appear to be needed, since the film doesn’t try to curl or climb up the blades.

SLITTING THE FILM

When the film cartridges are in place, the slitting head is lowered into position and the blades pierce the film and come to rest against a ¼ inch thick block of Teflon.

The drive tool is a short length of ¼ inch steel rod which I flattened and notched to fit the take up cartridge.

For these pictures I was using some unperforated 35 mm microfilm and could actually turn the tool with my fingers. Normally I would use a Black & Decker (no company ties) power screwdriver. A 36 exposure roll can be slit is about 15 seconds.

The finished film is stored in the take up cassette until needed.

Yes, that is an EFKE KB25 cassette in the pictures. The cassette is reusable, but the film is too grainy for Minox use. I might try some in the 16 mm format for my Minolta.