Bronica SQ-Ai 120 back - worth repairing?

[Colin Corneau]

I have an extra 120 back for my MF kit. However, this one 'eats' rolls, as I've found out the hard way.

It just winds them through all the way to the end, without ever 'clicking' into place at the beginning of the roll...end result is a wasted roll of film.

Is this common? And more importantly, is it hard to fix? Wondering whether I should just chuck the back and look for another one, or if it'd be easier/cheaper to repair it.

Many thanks, all
Cc

 

[vdonovan]

It might be hard to find someone to repair it. At the moment you can get a new 120-i insert for $59 from KEH, but in the past they have had them for much cheaper.

 

[asp.artist]

It seems pretty common. To my eyes it looks to be a bent pin on the insert. I had a problem with a couple of inserts from KEH, and we went through a few rounds of exchanges to get it right (which they did very nicely). I did not try to repair them.

Anne

 

[DWThomas]

That's what my very first SQ back did -- pretty disappointing! The cheapest solution is probably another back. As Anne mentioned there's a little mystery interlock pin that interacts with the body and might be bent/broken/missing. Bent might be DIY fixable. There's actually two segments of that interlock pin, one in the insert and one through the back shell frame. They have to couple, and especially the internal one looks like an awfully small diameter to reliably operate its mating pin.

I suppose it could be crud in the internal indexing mechanism in the insert interfering with the film travel sensing also.

 

[evilhomer78]

I've taken apart a couple of my sq-a backs. I could be a number of things, dirt, lack of lubrication, miss-alignment, broken or disconnected spring (there are a few little ones in there). I had a back with the same issue (it would only stop on a frame every so often), turned out that a ratchet lever was missing the gear its supposed to stop by fractions of a millimeter, I bent it back into position and the back works flawlessly now.

Here is a picture of the internals of one of my SQ-a Backs (220 same as 120 but more stops in the counter).

 

[vdonovan]

Thanks for posting this picture. SQ owners salute you.

I've taken apart a couple of my sq-a backs. I could be a number of things, dirt, lack of lubrication, miss-alignment, broken or disconnected spring (there are a few little ones in there). I had a back with the same issue (it would only stop on a frame every so often), turned out that a ratchet lever was missing the gear its supposed to stop by fractions of a millimeter, I bent it back into position and the back works flawlessly now.

Here is a picture of the internals of one of my SQ-a Backs (220 same as 120 but more stops in the counter).

 

[Uncle Goose]

Open it up and try to see what's wrong with it, after all, you have nothing to lose, sending it out for repair will be more costly then buying another one. So why not try to do it yourself.