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Cooltouch
Tinkerer
Username: Cooltouch
Post Number: 54
Registered: 01-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, January 02, 2010 - 02:43 pm: | 
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I just recently bought a Bronica ETRSi outfit that came with a 120 and a 220 back. Haven't used the 220 back yet, but I've put a couple rolls of film through the 120 back.
And the spacing is all over the place. It varies from maybe a 1/2mm overlap to a gap of about 15mm, and there appears to be no pattern to the variation.
I know that film loading can affect correct spacing with some cameras, so I was very careful when I loaded the film on this camera. Even so, frame #1 was partially exposed prior to taking on both rolls. I've just loaded another roll onto the insert and this time I was very careful not to let any slack appear at all. We'll see if this helps any.
I was lucky enough to find a repair manual for the ETRSi at Butkus's site, but unfortunately it includes no information on the backs. So, I'm wondering if anybody here knows of a source, or who can perhaps pass along tips for troubleshooting, repair, etc?
Thanks,
Michael |
Paul_ron
Tinkerer
Username: Paul_ron
Post Number: 181
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, January 04, 2010 - 02:46 pm: |
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The spacing is controled by a 2 soft metal waffer gears in the counter mechanism in conjunction with a gear that sences film is rolling by (one of the rollers inside the back where film passes over it).
If the sensor wheel is sliping it will show spacing problems and when the gears get worn, it also shows problems like you are having although it may skip frames n not stop at all in some cases.
Open the top plate and see what is happening when you wind film in the back? You will have to remove the lever and peel back the leatherete to access screws. Once the top is off put the lever back on and crank away with a film backing paper in it. |
Cooltouch
Tinkerer
Username: Cooltouch
Post Number: 57
Registered: 01-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, January 04, 2010 - 10:53 pm: |
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Thanks for your reply, Ron. I don't really see a "top plate" on the back or the insert. By "top plate" are you referring to the plate under the leatherette on the right side of the insert? "Right" as in looking down at the camera when holding it as if to take a photo?
I guess I should spool some backing paper onto an extra spool and watch the transport process.
Also something I noticed earlier today that I'm wondering might be related to this. I had to take about six or so exposures on frame 1 before it would advance to frame 2. At first I thought maybe the film was advancing but the counter wasn't. I even removed the insert from the back (in a changing bag) to check if the film had advanced, and it hadn't. And there was no appreciable slack in the film and paper either. So, I wound everything back up on the film spool and then reloaded it. Tried taking some photos again, and same thing again. I went through this probably four or five times -- took a few exposures on frame 1, then opened up the back in the changing bag, respooling the film and reloading it. Finally I just decided to keep firing and cocking and firing and cocking until it advanced to the second frame. Which took probably half a dozen exposures before it did so. And NO, I did not have the multiple-exposure lever pushed down.
After the film began winding, the camera appeared to behave normally. So far I've shot a total of 7 frames on this roll, and the counter at least has been advancing normally. |
Paul_ron
Tinkerer
Username: Paul_ron
Post Number: 182
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, January 05, 2010 - 07:36 am: |
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The top plate is the workings of the insert on the top. When you remove the top plastic of the insert, that is the "top plate" with all the gears n things on it.
Peel back the leatheret on top to expose the little screws at the corners. I'm not sure, I don't have one in front of me right now but I think there are 2 screws on the underside as well.
Remove the lever, peel off the center leather dot and you'll see a large screw. I think that screw is a reverse thread so try both directions and see which loosens?
Carefully lift off the plastic cover. Once you have it opened up run the backing paper through as if it were film and see how the mechanisms are working. I'll bet it's the small waffer gear, (it has notches in it) directly under the counter wheel. Very common problem not repairable though unless you have one to swap from a junker back that is still good. Most junker backs have striped waffer gears.
BUT there is still hope. I find alot of backs just need their screws tightened a scooch. For some reason they loosen a bit and things start to slip.
If you need a back, I have extras, I can sell you one cheap.
Paul Ron
automax1@juno.com
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Cooltouch
Tinkerer
Username: Cooltouch
Post Number: 58
Registered: 01-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, January 05, 2010 - 10:53 am: |
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Thanks for the follow-up Ron. I'll have a look. If it appears that the wafer gear is trashed, I'll drop you an email about getting another back (or two) from you. |
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