Hello, This is my first post here, as I am relatively new to photography practice, despite being rather proficient in theory. I have recently acquired a Zenza Bronica SQ-Ai. The camera seems to be in mint condition, with Zenzanon-PS 80/2.8, ME Prism Finder S and 120 film back all in excellent condition and a SQ-i Motor Drive (missing original crank). The 80/2.8 shutter fires accurately and the mirror pops up and back down again as it should - no issues there. The problem: When the SQ-i Motor Drive is attached, it will only fire in multiple exposure mode. Removing the Motor Drive and manually turning the rather hard to grip advance assembly solves this problem (which I would suspect would be the same with the original crank); however, this is far from ideal, as I will miss most shots fiddling with the thing! Any idea why this might be happening? Help would be greatly appreciated. Regards, Scott PS. If you have a spare winding crank, let me know and maybe we can work out a price.