After seeing some of you struggle trying to make a slitter to cut down 120 film down to 127 width, I thought I'd share another contraption I have on the shelf. Now, this is just half of the project as I still have to make a device to re-number the frames and spool the film back onto a 127 spool.
So, this is the thing... and it works very well. Instead of unrolling the film before cutting it, I opted to cut it right on the spool!
Much more reliable since it can be done in full daylight and you can actually see what's going on.
I used a rechargeable screwdriver which is held in its charging base. I also have two blocks of wood that hold both centering bits. To be precise, I drilled a single block and cut it into two parts. The bits are made from two screwdriver bits I had which I filed so they would fit the ends of a 120 spool snugly.
The cutter is a single edge razor blade (with a steel back like is used to clean windows after painting) which gets attached to a hinged block. To make things stronger, I used some bent steel plate which creates a pocket for the blade to slide into. A small catch prevents it from popping out. I use the big paper clip as a guard so nobody gets hurt when the blade is in. One of the big advantage of using such a blade is that these are super cheap and super sharp. Film is somewhat abrasive and you can definitely feel it when you cut through.
To use it is simple. Put the film in position, (hook up car battery charger to the poles... my screwdriver's battery was dead so I had to improvise
), load a blade in, start the screwdriver rotating clockwise, drop the blade and keep pushing on it until you can feel the spool's ridges.
That simple. Perfect cut every time since the blade is on a fixed hinge.
Anyways, as usual, a few pictures. Hope you find this thing inspirational.
On a single roll of 120, with re-numbering of the frames, it should be possible to get about 20 frames minimum.