Fuji GW690 Winding Issue- Any/all input welcome

[bwesso]

Hi everyone- just scooped up a GW690 off of ebay for cheap as a for parts/repair lot. It seems very close to being fully functional-- the shutter fires with and without film just occasionally slips up and gets locked up midroll. With a quick google search, it seems like this is a pretty common issue, but no one offers any solutions aside from "send in for repair".

I've noticed that the issue seems tied to the frame counter- the cog below it that stops the advance lever at each frame will occasionally not engage and this causes the lock-up. I think this issue is more likely to happen if I try and advance the film quickly, so it makes me think some other gear is slipping. Just curious if anyone has ever worked through this issue and could offer some advice.

If additional info is needed, I can be more thorough-- writing this from work haha

Thanks!

 

[Dan Daniel]

There is a very thin small spring that sits at, if I remember, about 12 to 3 o'clock and pushes a pawl into the frame metering disk. Look at this area to see if the spring is weak or not sitting right. Sorry I can't be more specific but it's been a while.

OK, found the manual. It's the assembly in the lower right corner. Might even be spring 4-87. Anyway, check this area's operation. I might have made a new spring with a thicker material to get more pressure, don't remember.

 

[bwesso]

Thanks Dan, I will check it out when I get back home for the day. Fingers crossed

 

[bwesso]

After some further poking around, I was able to better figure out what might be causing this. The springs were fine, but it is actually the metal arm that pushes the pawl out of the frame metering disk that is not engaging. It is intended to be engaged when the rack is released.

Weirdly, I cant manage to balance having that arm engage AND the shutter fire. Fiddling with how the rack sits on the shutter-charging gear, I can only have one issue resolved at a time. When I am able to get it to actually engage that arm, the shutter gear is one slight turn away from firing the shutter. I think that it could be solved with slightly shortening the long spring that yanks the rack back, increasing its tension.

Do you think that would be particularly risky? I assume its lost a little strength over nearly forty years and could be causing the shutter arm to not fully complete the shutter firing cycle. I can add pictures later, as Im sure it is tricky to picture.

 

[bwesso]

If you watch this video, the part that is not engaging for me is that little tongue that sticks out at the top right of the mechanism (in this video's angle at least).

 

[bwesso]

So finally got it working at a consistent clip. Hooray working camera at a discount!

For anyone else trying to remedy an issue with similar symptoms, I would check to make sure that the rack that charges the shutter is making proper contact with the metal piece that disengages the frame-locking pawl mentioned above. It is relatively easy to adjust how the rack sits on the gear that charges the shutter to ensure that it extends fully after each frame. In my case it was not. It did take a little bit of trial and error to figure out which placement worked so that I could fully advance the advance lever, get the shutter to fire, and engage that third piece.

The other thing I would check is that the shutter release on the leaf shutter itself is not jammed in any way. I noticed that the shutter was relatively hard to trigger, so after removing the front element and the shutter speed dial, I wiggled it and fired it a few times from there, and weirdly enough that seemed to finally remedy the issue.

I did slightly shorten my long spring by maybe 3mm, but that did not immediately solve the problem, so I probably would not do that if I were to need to fix it again. I did see that Ace Hardware stocks a very similar spring that may have worked as a comparable replacement. It was about 1.5" by 1/8" with loops and a similar deflection length. Made by Prime-Line.