i just finished fixing focus issue on my newly acquired C330, run 2 roll film to test, for a reason i get the wind lever not stopped at frame 12, it keep rotating as if it is the end of the roll. I tried with the 3rd roll of film, i can confirm that there is real issue, on mine.
I read on photo.net that there is a restriction gear inside upper chamber act as detector when the thickness of film on the spool is reaching 12 frame, i try to figure it out how it works (it must be hard as film might vary in thickness), then i test the my camera with a new film installed on the top chamber, just to simulate a thick film on the spool. Then i wind up some empty paper on empty spool to simulate half size of new film thickness, all spool recreate the issue. So i don't think the theory of gear to detect thickness is correct.
Again, i open the right cover of my C330. After trying to simulate the issue for a while, i see how it work and how to cure the issue.
See picture below :
how the camera know if it should count only up to 12?
1. It use information from the film pressure plate. Switching (rotating) the pressure plate to 120film will raise a small metal tab on the top area of back cover.
2. The tab will push a small lever inside top film chamber, will link to a bar (close to the red arrow on the picture) which will be pushed forward.
3. On the bar, there are 2 springs which connected to small brass plate. Once the bar pressed, the brass plate will rotate down. The brass plate has a catch area that will stop the rotating frame counter when it reach count of 12 (green arrow in picture)
4. The frame counter plate, have extra 2 plates underneath, one of this have a tab which will be stopped by the brass plate after frame 12. (blue arrow). The restriction wheel will detect film movement in the upper spool, and will rotate the frame counter plate, there are other mechanism to stop the counter plate for every count added, i will not discuss it here, but when it reach frame 12, the stop tab should ALMOST touch the brass plate. So when we try to wind after frame 12, the frame counter should stop rotating, and the restriction gear will slip off (jump) so we can keep winding to the end of roll.
The problem is, the brass plate rides higher than it should be, this stop the frame counter just before reaching 12. To fix the issue, the brass plate should rides lower, in other word, the bar pushing the brass need to move farther to the front, means, the tab on back cover plate should push it deeper.
So to fix it without too much effort, i add 4-6layers of clear tape on the tab on the camera back cover. This will add extra 1mm push on the bar inside, and i fix the issue !! In case you have the same issue, try to add the tape first without opening the camera right plate, worth to try.