Friday, 12 August 2011

Bronica SQ-A Film Back Disassembly and Repair

I had a problem a while ago with my Bronica SQ-A. I had a film jam that damaged the transport mechanism in my film back. I've repaired quite a few cameras over the years (non professionally) so I thought I would give it a go.

The symptoms were as follows - I could turn the film advance lever as many times as I liked, but the frame counter wouldn't move and the shutter wouldn't lock. Changing the back returned the camera to normal operation. Removing the film from the back I found that turning the film advance crank did not result in the take up spool turning. With a bit of assistance the spool would turn when the advance crank was turned but there was little or no torque being transferred from the crank to the spool.

Fixing a Bronica SQ-A 120 Film Back with a Broken Transport

As it turned out, there's a spring in the drive train (to absorb shock loads I assume) that was no longer transferring power from its input to its output. For details of the strip down and fix, I documented the process in one of my Flickr sets here:

Hopefully this will help other people as I couldn't find any similar information when I took it apart. N.B. Be careful to pay attention to the screws that I have noted have left handed thread! ;)

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