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Marco
Tinkerer
Username: Marco
Post Number: 16
Registered: 10-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, April 15, 2010 - 01:01 pm: | 
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Just got this cute Soviet era contraption in almost immaculate condition. I may be wrong in blaming the winder but that is what the seller said (had been working fine until someone wound it a few turns too many).
Is there some standard treatment for non cooperative spring motors (a bit of controlled whacking, or fiddling with the winder wheel) before considering disassembly? No small feat apparently, as a powerful spring-loaded mechanism seems to be lurking inside.
Many thanks in advance for any suggestions. |
Scott
Tinkerer
Username: Scott
Post Number: 92
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, April 15, 2010 - 01:32 pm: |
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It's probably the same problem as a watch that's been over-wound. The spring needs to be "let down", as they say.
I'd recommend wearing gloves and goggles when you dismantle the thing. There can be a surprising amount of energy stored up in that 2-3 feet of sharp spring steel.
Also, rather than trying to begin by opening up the spring housing, first try to get the spring housing off of the camera intact, as a unit. |
Marco
Tinkerer
Username: Marco
Post Number: 17
Registered: 10-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, April 17, 2010 - 06:33 pm: |
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Thanks a lot Scott.
Before attempting a motor job I preferred to first explore the shutter unit and shutter blades.
Following an old post at ussrphoto.com camera forum (thank you Luiz Paracampo) this is what I did: (i) set camera to B and infinity, (ii) loosened three screws around the distance scale ring and removed it, (iii) unscrewed lens unit, noting exit position, (iv) unscrewed grooved ring (retained by a notched screw head), (v) carefully removed speed ring to expose shutter unit.
Found nothing unusual in the shutter, although my technical limitations may have made me ignore the obvious (for instance, never managed to fire the shutter). Found and removed lots of oily goo around helicoid and now suspect oil may have seeped to the shutter blades. Begun cleaning blades with Ronsonol applied with lens cleaning tissue, but no positive reaction after a long hour and lots of paper.
Have now reassembled the camera and shall continue cleaning shutter blades, this time from the film box end only. Will keep you informed of any progress.
By the way, in watch mechanics' fora they insist there is no such thing as an overwound spring as the cause for a spring system not working properly. Who knows.
(Dear Moderator, please excuse typo in thread name. Could this be amended, for better future reference? Thanks in advance) |
Scott
Tinkerer
Username: Scott
Post Number: 93
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, April 17, 2010 - 11:59 pm: |
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Sounds like you have cleaned at least the part of the blades that is visible and acessible (without disassembly).
But remember that part of the blades (and the actuator rings which twist and are what actually moves the blades) is not visible (without disassembly). A complete tear-down is the 'proper' way to clean those parts, but what I prefer to try is to drip a little naptha directly ONTO the blades, then tilt and twist the camera around, let it get onto the actuator rings, etc., then cock and release the shutter a few times before it evaporates. Usually frees up the blades.
I have had clocks, watches and cameras which have stopped working because there was too much tension on the springs. |
Burzmali
Tinkerer
Username: Burzmali
Post Number: 1
Registered: 06-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, June 09, 2010 - 04:28 am: |
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I got this very cute camera from a flea market for the equivalent of ~$5. it seems a little used, but overall in good condition.
After loading the first roll of film and going through the first few frames, the spring motor got stuck. Now the shutter won't fire.
It would be great if you could share if/how you managed to repair it. I really like this camera and would love to use it.
Thank you in advance 
p.s. I'm also not very sure how to properly operate it. especially when to release the bottom knob. |
Marco
Tinkerer
Username: Marco
Post Number: 18
Registered: 10-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, June 10, 2010 - 07:50 pm: |
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Well, to tell you the truth I have not made much progress here, other than getting hold of other four cameras of the same model, each carefully boxed and instruction manual thrown in (also at five bucks apiece - seems to be the international going rate) in different stages of malfunction (seems someone in my country dumped on the market a bagful of defective units collected over the years). I'll now have to device a procedure to try and repair them simultaneously and follow Scott's suggestions.
Once your camera hopefully returns to the condition that allowed you to shoot a few frames, please bear in mind that (a) it is not advisable to load this spring motor with more energy than required to shoot three or four frames at a time (overcharging seems to contribute to the motor getting stuck again); (b) as to the bottom knob: fully screwed-in is the position for taking pictures; fully screwed-out / unscrewed allows you to rewind film.
Wish you best of luck following Scott's sensible recommendations. |
Burzmali
Tinkerer
Username: Burzmali
Post Number: 2
Registered: 06-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, July 04, 2010 - 09:31 am: |
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Thank you.
I'll try to repair it by "letting down" the spring.
Will let you know. |
Burzmali
Tinkerer
Username: Burzmali
Post Number: 3
Registered: 06-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, July 06, 2010 - 03:59 am: |
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I managed to repair it. I'll explain below in some detail how I did it in case somebody else runs into the same problem.
You’ll need a set of precision tools (screw drivers and a small plier), a clean work surface and good light. It should not take more than one hour.
1. open the camera back just as you would to load film. the hinged door that holds the film in place will hinder you while you work. you can tape it closed so it stays out of the way.
2. you need to remove the plastic top of the motor winder by removing the 3 small screws in its side. once you removed the plastic top, you'll see an aluminum cylinder with a yellow metal top - this is the spring housing and the big greasy mean looking spring is curled up inside. you don't need to open it (in light of Scott's advice above, it is probably safer not to).
3. remove the top half of the camera's aluminum case by removing the 3 screws (one on each side and one on the back). when you take it off, 3 pieces will come loose: a metal brace that was holding the hand strap to the case and the 2 pieces forming the shutter button. make sure you don't lose these.
4. the spring housing is held in place by 4 screws. you need to remove these. they have different lengths (2 long, 2 short) so make sure you remember which goes where (I did not). the screw to the front of the camera closest to the viewfinder window goes through 4 collars paired 2 by 2. make sure you remember where they go.
5. once you took out the 4 screws, proceed to disengage the spring housing from the cog bellow. you do this by pushing it gently upwards using a small screw driver as a lever. when it comes loose, you'll hear the spring unwind. that's the sound of your problem solved . two more collars will fall from its bottom. make sure you don't lose these either.
Now you're good to reassemble the camera. You can spend a little time admiring it’s maze of springs, spiked wheels and levers. It takes soviet engineers to make such a complicated camera. Maybe you can understand it’s workings. I couldn’t 
6. put the spring housing back into its position. in order not to have the 2 collars on it's shaft fall off all the time, you can work with the camera upside-down.
you need to make sure first that the shaft in the spring housing and the shaft in the cog below (on top of the take up spool) are properly aligned. then you'll have to struggle a bit to connect them properly. This is the only hard part.
7. before you put the 4 screws back, take a moment to check that the camera works properly.
place a piece of spent film in the back of the camera with the holes fitting the spikes of the sprocket. rewind the spring and fire the shutter. make sure that the film advances correctly by counting the number of holes. this is a good moment to test how far you can rewind the spring without getting it stuck. if it gets stuck, repeat step 5 and 6.
8. put back the 4 small screws. the one with the 4 collars is the hardest. for me it worked with the camera on its back so the screw was placed horizontally and the collars could stay on it while I worked. Since I did not remember which of these 4 screws went where, I used one of the smaller two for the position with the 4 collars (using one of the longer two resulted in the spring motor getting stuck immediately).
9. check again that the camera works - rewind the spring and fire the shutter a few times. if it doesn't, it's probably because you tightened too much the screw with the 4 collars and it blocks the small cog below.
10. put back the top half of the camera’s aluminum case. Again, it’s easier to work with the camera upside-down so the 2 pieces of the shutter button stay in place. The metal brace that holds the hand strap goes through the strap and then through the twin holes in the case with its ends pointing towards the bottom of the camera. Once the camera case slides in, the shutter button and the metal brace will be held firmly in place on their own. Put back the 3 screws.
11. put back the plastic cap on the spring housing/rewind knob by securing it with the other 3 screws.
And that’s it. Load film, shoot away, have fun with this little monster of a camera.
I think Marco above is correct: to avoid getting the spring stuck, it’s best not to rewind the spring more than 3 full turns. Actually one and a half turns is enough for advancing the film one position and there’s no risk in blocking the camera. |
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