Fed2 sticky shutter in 1/500

[Piltnik]

Hi,

Searching the forums for solution to my problem wasn't fruitful so here it goes.

I have a Fed2 that had been working perfectly at least until last January-February or so when it was left sitting in a drawer until I took it out again in mid September.

In September I intended to bring it along for a weekend trip and good thing that I checked the camera before packing it in! I found that during the approx. 6-month hiatus the shutter's 2nd curtain had developed a sticking habit at 1/500 speed. Other speeds work fine (don't know how accurately, but at least consistently), only at 1/500 the 2nd curtain stops about 3 times out of 5 at about midway across the frame. It doesn't seem to make a difference whether I "squeeze the trigger" or jab it, the curtain will still stick.

My mistake was to leave the camera shutter cocked (and probably set to high speed, too) when I put it away, so probably now the 2nd curtain's spring is tired? But usually in such case isn't it the slow speeds that stop working rather than high speed?

 

[wolves3012]

Leaving the shutter cocked doesn't make a lot of difference to the springs and the set speed makes no difference at all. Probably the lack of use is the big culprit.

You could try firing the shutter a lot, to re-distribute the lubricants but the problem suggests the camera is in need of a proper CLA. When the curtain stops, can you "help" it across, gently, with a fingernail? It's not actually jammed there is it?

 

[Piltnik]

Thanks, I remembered reading somewhere that leaving shutter cocked for prolonged period of time may screw up shutter's tensioner springs.

The curtain is not jammed, I can push it across manually. However it seems like when doing that there's no tension in the curtain?

One thing makes me wonder is that why it happens only at 1/500 and not at any lower speeds?

 

[wolves3012]

Leaving it cocked for years might weaken the springs a bit, probably not with modern steel springs though. I can't say definitively why only 1/500 is affected but I can suggest a possible reason: sticky lubricants can cause an unintended coupling between the two curtains, so the second one gets dragged along a little by the first - that's because they share common axes of the rollers etc. If the second curtain is borderline on closing, the first one has the least time to accelerate and drag the second past the stickiness at 1/500. I don't claim that's right, just an idea.

 

[Piltnik]

I took a closer look at 2nd curtain's current MO and it seems that second curtain actually does stick, roughly at the same place every time, and that now it's started occurring at 1/250 speed, too. It requires some force to pushi it past sticky point by finger. However sticking almost never happens when the camera is pointing down...

I guess some camera surgery is now unavoidable, though I was really hoping to avoid that as I'm afraid to break it, and I really like this camera.

 

[wolves3012]

There may be an easier answer, based on your description: the second curtain latch. To get at it you will need to remove the top cover but you will not need to get into wholesale dismantling.

The latch is a crescent-shaped arm that sits partially around the speed selector mechanism. It's lowered into position when the shutter button is pressed and it traps the second curtain. It gets released when the first curtain cam knocks it aside or when the shutter button is released. Once the top is removed, it should not be hard to see which part I mean. If that latch is not operating correctly, the shutter can remain nearly open. A small spring pushes the latch inwards and downwards - releasing the spring allows the arm to be removed for cleaning and re-lubing of the (long) pivot rod.

Personally, I'd be inclined to try that before digging any deeper.

 

[Piltnik]

Thanks, I'm grateful for any tips! I'll give that one a go over the holidays.