Skipped frames.

[fidget]

I've have a few FEDs which intermittently skips frames, that is when winding on, two frames are passed. My Zorki 6 is now doing this regularly. At the bottom of the toothed sprocket is a peg which pushes another peg on the cog below. When the lower peg returns upwards after a shutter release it comes to rest on the bottom of the peg on the sprocket, rather than in front of it. So as the sprocket is turned it can't push the bottom peg until it's done one full revolution.
Anyone seen this??

 

[Xmas]

Dave

Yes I got a Mir that has the same syndrome, it came in the same parcel as the Zorki, it had a damaged filter ring, a jammed shutter and no pressure plate. i bought it as a parts camera...

If I can see what is wrong I'll post.

Noel

 

[fidget]

I've got a bit of a theory about this...in the case of the zorki, I've just been working on the winder ratchet, not the one for the lever, the one that stops the gear train releasing. I notice that when I wind up the camera so that there is little or no 'backlash' (as seen when the curtains move back a fraction at the end of the last wind stroke) it will miss a frame. If I wind to the limit very gently (I see the curtains wind to the limit then back about 1mm) and allow a little back-lash, it releases perfectly. I believe that if the ratchet was set up to allow a little backlash the sprocket wouldn't move as for round and the pegs would align as they should. Off with the top again.
This is all very ..er.....'character building' ( as they say when you've thrown your golf clubs into the water hazard). I may need to go play with a nice FSU cam to remind myself why I do this.....

 

[fidget]

After a few attempts at altering the "bite" point of the ratchet in the gear train, the shutter works without missing any frames. I can't make it do it if I try (which was by winding it hard against the stops). Cured, at last!
I was so pleased that I rebuilt it and even cleaned it up before I tested other aspects of it's operation. Would you believe it, a new problem! These are just the best for entertainment aren't they? Now and then it will release the shutters together, sometimes in a way which opens at the left of the film aperture. This problem and I are old friends, but at the moment I don't have the stomach for another strip/build.
I am visiting the mountains of the Sierra Nevada, Las Alpujarras, soon for a holiday, with the odd restrictions on what can be taken on a flight and the need to avoid turning it into a photo session, I will leave the Nikon and the MF kit at home and take an FSU for a "fun" holiday. Guess it won't be the Zorki 6.
I need something which is reliable, smooth and just cool (poser?), looking like the Kiev +J8 +J12.