Fed-1, Slow 1/500 shutter

[Sid836]

I have acquired a Fed-1, probably not CLAed ever, and its top shutter speed of 1/500 seems to be slow, could be like 1/250 or even slower.
Is it possible to fix this? Could it be done by applying more tension to the second curtain, or both?
My negative came out so dense that you could use it as a solar filter (kiddin', don't try it ).

 

[KnipsOmat]

Before you do anything: what about the other speeds? Are they o.k.? Or is it just the 1/500s?

Curtain tension is, in most cases, not the solution to the problem. If the second curtain has a significant higher tension than the first one, you will not get a shorter exposure. You will get uneven exposure across the frame instead, as different curtain speeds mean your travelling gap has not a constant width across the frame.

If the tension difference is too big, parts of the frame might even not be exposed at all, when the second curtain catches up, closing the gap.

 

[Dez]

It is almost certainly a matter of needing a good cleaning and re-lube. In any case that needs to be done before you try anything else if you want consistent results. The FED is a pretty simple camera, and this is a good candidate for a DIY project, especially since the cost of having it done professionally could be double what you paid for the camera.

Cheers,
Dez

 

[Spanik]

Don't even think that a camera of that age would have its speeds within 10% of the dial figure. Might not even get 20%.

 

[Sid836]

The other speeds are o.k. B is 100% perfect : )))), 1/25 pretty close, 1/100 almost there, 1/250 looks to be like 1/200 and 1/500 is for sure like 1/250. I had a few shots at noon time that gave out a bullet proof negative.
(and there is a hole on the second curtain, now fixed).
I have re-lube it carefully and will have a run with a short roll of film to see what happens.
Before reading this, I have tried to increase the tension of the second curtain (boy, that needs two people to get the job done), and I think I gave it three, maybe four turns before locking it in place. I had a look at the curtains running against strong light and seemed that the entire frame opens completely, but I guess a real try will show if it is o.k.

I have tested the speeds with the sound test with audacity. It may not be accurate, but what worries me is that 1/250 and 1/500 "sound" exactly (or almost) the same.

 

[wolves3012]

You cannot adjust the speeds independently, only overall. The different speeds are achieved by the angle the speed selector turns while the second curtain is held and this ratio is fixed. If your 1/500 is running slow and there is no unevenness in the slit-width, your 1/250 would also run proportionately slower IF the shutter is running correctly. I would be surprised if both speeds were actually accurate but they should be somewhere in proportion of 2:1 or close to it.

If you have 3-4 turns tension on the second curtain that is about as much as should ever be needed. If that was 3-4 turns extra then you definitely do not have a smooth and free-running shutter. You should have less tension on the second curtain than the first as well.

If you have access to a CRT-based computer screen (not common nowadays, I know), try viewing a white raster whilst looking through the shutter and firing it. You should see parallel, diagonal stripes at 1/500 and wider ones at 1/250. One tip to ensure you don't have capping is to aim a low-power green laser pointer at each end of the curtains in turn and fire the shutter. If you see a flash of green as you trip the shutter, with both ends, there is no capping - although the exposure may still be uneven.

 

[Sid836]

Thank you for the advice.
I had 3-4 turns on the second curtain from the complete relaxed position. By the moment I had removed that tinny screw that secures it, it got completely unwound.

I'll try a speed test with a small roll of film to see where I stand. If I get capping, I will loosen by one turn the second curtain.

 

[Ron (Netherlands)]

I'll try a speed test with a small roll of film to see where I stand. If I get capping, I will loosen by one turn the second curtain.

Before doing that, you could take off the body shell by unscrewing the little screws at the front and back and the two bigger screws at the front. You also have to take off the lens mount ring (4 screws). When you have taken off the body shell, you can have a look through the shutter and quite easily ascertain if it is working well at all speeds. Only after that is done I would shoot a test film.

 

[Dez]

Any adjustment is a waste of effort until the mechanism is clean, or results will be highly dependent on temperature, humidity, and whatever position little pieces of crud in the works decide to take at a given moment. Taking the top off allows you to flush out the congealed lube from the rotating bits of the shutter selection mechanism. Taking the body off allows you to blow out and re-lube the pivot points of the shutter drum and spindles. It's not a complete CLA, but it will at least get you to a point of consistent operation, and do a more thorough job of checking for pinholes. With the body off, you can get a reasonably good idea of the evenness of exposure by looking through the shutter aperture at a blank, well-lit wall while going through the different shutter speeds. This is not difficult to do if you are at all handy, and it really is necessary.

Cheers,
Dez

 

[Sid836]

Before doing that, you could take off the body shell by unscrewing the little screws at the front and back and the two bigger screws at the front. You also have to take off the lens mount ring (4 screws). When you have taken off the body shell, you can have a look through the shutter and quite easily ascertain if it is working well at all speeds. Only after that is done I would shoot a test film.

Thank you! I did that and everything seems normal. It looks like the whole frame opens up evenly at every speed.
Strange, when I hold the camera upside down, at B the second curtain does not close.

Any adjustment is a waste of effort until the mechanism is clean, or results will be highly dependent on temperature, humidity, and whatever position little pieces of crud in the works decide to take at a given moment. Taking the top off allows you to flush out the congealed lube from the rotating bits of the shutter selection mechanism. Taking the body off allows you to blow out and re-lube the pivot points of the shutter drum and spindles. It's not a complete CLA, but it will at least get you to a point of consistent operation, and do a more thorough job of checking for pinholes. With the body off, you can get a reasonably good idea of the evenness of exposure by looking through the shutter aperture at a blank, well-lit wall while going through the different shutter speeds. This is not difficult to do if you are at all handy, and it really is necessary.

Cheers,
Dez

Opening it up as per Ron's advice, I had cleaned and re-lubed everything. It seems that everything is now o.k. except that the 1/500 is almost a stop slower, closer to 1/250.

I guess that all it takes now is to make a test with a film. I want it to work badly as I enjoy taking photos with it far more than I do with my other a lot more finely refined cameras.

 

[Ron (Netherlands)]

Strange, when I hold the camera upside down, at B the second curtain does not close.

The second curtain latch is (in part) responsible for opening and closing the second curtain. Its quite technical to explain: there are two springs that give in opposite direction pressure on the latch. The little spring at the top of the latch pushes the latch down when the shutter is fired and when on B it will hold the second curtain.
The other spring is a flat spring mounted at the bottom of the camera (you can see it when loading a film). It will give upward pressure to the latch: when the shutter button is released this spring will bring the latch back in its starting position, releasing the second curtain. Guess from my English this is hard to understand perhaps others can jump in to make it more clear...
Now the tension of these two springs must be in 'balance'. If for reason the original balance is lost, the second curtain latch might not work, e.g. when the camera is upside down. In that case the work of natural forces added to those of the springs might result in an improper working shutter.

 

[Dez]

If the second curtain does not close when it's upside down, it shows that the second curtain latch isn't in quite the correct position. Strangely this problem is more common when the camera is the right way up. The best remedy is to take the top off , clean and inspect the shutter latch mechanism (the gubbins under the dial). You can see how the latch toward the rear of the camera comes up to release the trailing curtain when the button is released. It may be that the flat spring at the rear of the bottom plate isn't pushing hard enough on the end of the shaft that controls the latch. Easy to fix, but you need to observe and understand how the latch works to get it right.

Cheers,
Dez

 

[Sid836]

The flat metal under the camera seems to push the latch hard enough. I guess that it is not in balance with the other one atop as Ron states. That spring is it the one under the shutter button?

--- Edit ---

I did it! Thank you very much for your invaluable help. Now it all works fine. Top speed is something like 1/400, perhaps a bit less, but it is not like before. I will be out with this tomorrow with a Kodak Plus-X in it.
Thank you guys!