but those damn O-rings…

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from the patent:

A film carrier for use in photographic or projection apparatus in which a film supported on a pair of aligning film guides is transported by means of an endless belt ..

It is that ‘endless belt’ that breaks. The replacement parts are no longer easy to locate, at least not from the usual sources; however, these items were not made by beseler, only sourced by them. These belts are o-rings to most of the world. Size it; buy it; install – get back to making prints.

I measured a broken belt, finding it ranged from .91 to .96 in diameter – with that, and an approximation of length (using a string threaded through the roller path) I arrived at a McMaster-Carr part.. usasealing (shelf life est: 15years)

I have 2 negatrans for 120 film: one fitted with an omega adapter, the other, the one broken is for my beseler 45. I also have the negatrans for 35mm. Makes life with roll film much easier in getting through a batch of ‘work’ prints.

If you’re near UTD, or Marfa contact me for the part number; maybe one of my spares.