Broken Bronica SQ-A film back advice?

klou · Apr 16, 2014

Hi!

Recently I bought a second hand Bronica SQ-A and when I load the film the advance doesn't stop at the first exposure like it's suppose to and just carries on winding, through reading previous posts I figured perhaps the back is bust but does anyone have any suggestions?

Also, do you have any tips on how I could shoot with this problem or is it just not possible?

wildbill · Apr 16, 2014

throw it in the garbage. buy a replacement on ebay.

Alex Muir · Apr 16, 2014

I think it's probably no use and you'll need another. Don't throw it out. You can take spares off it if you need them. Sometimes the rollers are damaged on an otherwise good back. They are easy to change over if you need to.
Alex

wiltw · Apr 16, 2014

Hate to ask this, but are you certain that you loaded the film properly?

DWThomas · Apr 16, 2014

Alas, not the first time to hear of this symptom. The first back I bought did that, just cranked the film right through. In my case, I returned it to the seller.

There is an interlock -- a small cylindrical projection with a pin inside -- between the back and the body. If that pin were bent, it could be a problem. I've so far not disassembled a back, but it could well be fixable, maybe just some cleaning needed.

I agree with Alex, don't throw it out. If not repairable, it could at least provide spare parts, and there's no more being made.

klou · Apr 16, 2014

Absolutely positive it's loaded properly, used one a few times before and sat with a tutorial as well and still happens!

Ahh what a pain, thank-you for all your advice! Best get searching for a new one

wiltw · Apr 16, 2014

klou said:
Absolutely positive it's loaded properly, used one a few times before and sat with a tutorial as well and still happens!

Ahh what a pain, thank-you for all your advice! Best get searching for a new one

Sorry, but I had to ask. With the prices of medium format having plummeted to 10% of the original price, lots of medium format newcomers with used gear and zero documentation trying stuff out. Putting rollfilm in, wrong side forward to the lens, is certainly not all that uncommon for a newcomer to equipment.

klou · Apr 16, 2014

That's alright no problem, a lot of the time these things are down to silly mistakes aren't they!

John Koehrer · Apr 16, 2014

RB's have an interlock in their backs too.
There's an actuating pin in the body that pops into the back. This pin sometimes suffers from "sticky lube" and it looks like the back is malfunctioning.
If there's a similar system in the Bronica, it may just take a drop or two of Naptha/Alcohol/mystery solvent.

wiltw · Apr 17, 2014

DWThomas said:
There is an interlock -- a small cylindrical projection with a pin inside -- between the back and the body. If that pin were bent, it could be a problem.

There is an issue with the insert itself, which has all of the 'works', so it might be remedied by a repair guy, or simply by buying a good condition insert on the used market (since used prices for medium format is so very low, relative to repair labor).

The chrome cylinder with pin only serves as an interlock to the body, so that the body knows whether or not the film needs to be advanced. The insert (in the back) should nevertheless permit the user to advance the film to frame 1 (and stop there) even without it being mounted on a body.

There needs to be sufficient tension in the film for advancing the leader onto the takeup reel to cause the frame counter to advance to '1'...otherwise the film can be moving -- even to the end of the roll -- but the counter never advances to '1'.

I am unable to determine just how 'sufficient film tension' is signaled to the counter. I do know, from testing, that even if the roll has been properly tensioned and advanced to '1', as soon as you open the back to remove the insert the counter immediately resets to 'S'...tension has been lost! It might be the metal sensor at the back right of the insert which communicates 'back closed' that allows the counter to advance to '1' (or to lose count when opened), rather than 'sufficient film tension' status per se.

DWThomas · Apr 17, 2014

A few years back in one of these discussions, someone posted some pictures of the internals in one of those inserts. There are a lot of links, levers, pinions and gizmos in there, so I would imagine dirt or congealed lubricant could be a problem. I (so far) haven't had the time or patience to try to sort through all the interactions in my SQ-A -- mechanical or electrical. I was speculating that if that interlock were jammed, it might cause the insert to get confused. With the reverse bend the film makes over those rollers they can't help but turn, however in a quick look here, I'm not sure they turn anything. I vaguely remember some sort of slotted cam-like part in those pictures that suggest to me the insert measures spacing in some obscure way, perhaps based on compensating crank turns for some assumed winding diameter change. No doubt one of these days I'll have a problem and dig into it further.

Interesting beasties!

skysh4rk · Apr 17, 2014

Some time last year, one of my SQ-A backs suddenly became very difficult (actually more like impossible) to wind and would occasionally skip frames when I did manage to get the crank on the body all the way around.

I was a bit apprehensive about opening up the insert and playing around with its intricate insides, but I had a couple of other backs and had nothing to lose really, as the back was unusable in its current state.

After picking up some very small screwdrivers and an x-acto knife, I followed the directions from this link to open the insert up: https://www.flickr.com/photos/zzpza/sets/72157627089382019/

Once I got inside, I determined that there was a cog in there that wasn't moving as smoothly as it should have been while winding. I grabbed a q-tip, dabbed it in some WD-40, and gently applied it to the cog. That did the trick and I haven't had a problem with the back since.

I'm not saying that this is exactly your issue, but it is possible there is a simple solution.

That said, I was very surprised by how intricate these backs were inside; I'm glad that I didn't need to do any more in there than I had to.

Broken Bronica SQ-A film back advice?

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