Donald Qualls
Subscriber
Edit: I just pulled the frame counter wheel out of a junk Primo parts camera. There is a large toothed gear attached to the back of the counter wheel and there's a follower arm riding along this that tells the camera when a full frame has been wound up and stops the film from advancing until the shutter has been fired. I had expected that the gaps between these teeth would get progressively smaller to compensate for the takeup spool filling up, but they don't. (I think my Mamiya C3 does this...) So I don't know how these cameras make the necessary compensations, but somehow they do. So framing might be a problem.
Progressive shortening of the spaces is how turns-counters (like the ones in Graflex roll backs and my Super Ikonta B -- and the telescoping Minolta and Kiev 16 mm cameras, too) compensate for thickness buildup on the takeup spool. The ones that drive the counter with a friction roller (like an RB67 roll back or my Kodak Reflex II, and lots of other cameras including any that can switch between 120 and 220) don't have to compensate, because they're measuring the actual film that's rolled past the counter roller.