Compound Shutter

Discussion in 'Classic Manual Cameras' started by riccardo_mottola, Nov 7, 2007.

  1. I am trying to repair a Compound shutter which is doing always the same time.

    With much patience and following some instruction on the net, I was able to open
    it, although I needed to essentially fill it with unblocking liquid.

    Anyway, the cause is the air cylinder: it is almost stuck. It moves very hardly
    even when cleaned gently with paper and esane. The piston and the cylinder look
    without scratches, immaculate. The cylinder is still shiny brass and bears no
    traces of "beats".

    Ideas?

    The piston is asymmetrical, on one side it has a hole for a screw which doesn't
    reach the center hole though.
     
  2. I've worked on a (very) few of these -- yes, they're simple enough that even I can work on one and have no parts left over at the end!!!

    Make sure that all the other mechanical parts are assembled correctly and working well. If the cylinder and its "tube" are all clean and in good shape, the cylinder should move easily in the tube. Be sure that there is absolutely no lubrication on the cylinder or in the tube.

    Also make sure that the cylinder tube seals well when the end caps are put on. On at least one of my Compounds, I noticed that the end caps didn't seem to tighten very well; the threads were good, so I made new gaskets out of card stock paper and put them in, which made for end caps tightening better and also improvement in accuracy of the shutter. So, you can't have any air leaks at all in that cylinder assembly.

    Hope this helps.
     
  3. Could that screw be the "calibrated air leak"? There does have to be some way that the piston can let air by.

    Unfortunately, I have no experience with the Compound shutter. The only air-timed shutters I've worked with are Wollensak Optimo and the Rochester Optical Co. Victor shutters. In both of these, the air leak was just imperfection in how tight the piston was in the cylinder. (There's a hole at the bottom of the Victor stationary piston, but it is supposed be be plugged, as I learned the hard way.)

    These air piston shutters are really finnicky. It only takes a little wear and they leak too much air, or a little corrosion and they have too much friction.
     
  4. I will try to clean it better then. The inside of the cylinder looks very clean and the piston has no marks.

    Should it move freely without the caps? It doesn't here neither with nor without. I guess it should move even faster since it has a constant pressure on both sides.
     

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