Compound shutter problem

**Bill_1856** · 7-Dec-2006, 20:50

Last year I bought on ebay a beautiful Technica cammed 360mm Tele-Xenar in a large Compound shutter, which seemed to be working at all speeds. For various reasons I haven't used the lens since then, and now it fires only at what sounds like the maximun 1/100 speed, no matter where the speed dial is set. Is there anything to be done, other than send it out to a good shutter repair shop? Thanks.

**Patrik Roseen** · 8-Dec-2006, 02:56

It sounds like the same issue I had with a dial-set compur I acquired recently with a tele-xenar 270mm.

At first I thought it was the dial-set mechanic but that was not the problem.

What I discovered was that the trigger (or maybe catcher) for the 'clock-work' of longer speeds did not travel fast enough leading to the shutter-mechanics just passing by without the 'clock-work' ever getting into the motion so to speak. I gave the shutter APPROPRIATE lubrication and it works fine now. (Sorry for not being able to describe the mechanics with the right terminology!)

When realising the problem I also understood why excercising the shutter did not lead to any improvements since the slow 'clock-work trigger/catcher' was just sitting there.

If you are not handy in repairing shutters it would be wise to hand it in to a repairshop. Should not cost too much.

**Arne Croell** · 8-Dec-2006, 06:58

Since it is a Compound (no clockwork), it is likely that the piston in the airbrake timing device on top is stuck. When you cock the shutter with any of the slower times, that piston travels a certain way in the cylinder, the distance is given by the timing cam. When you release, it travels back to the starting position against the air resistance, producing the delay between opening and closing. If it never moves during the cocking procedure, that would lead to the effect you describe. Compounds are not too difficult to work on if you have jewelers screwdrivers and a few other tools, but if you don't want to go that route, find a repair person.

**Jim Jones** · 8-Dec-2006, 08:50

On my Compound, the end caps of the pneumatic cylinder are readily removable. With the caps off, if the piston doesn't move as you cock and trip the shutter, cleaning may solve the problem. Try removing the lens cells and the cylinder end caps, and flushing the cylinder with a residue-free solvent. Holding the shutter upside down while doing this will prevent solvent from getting into the rest of the shutter.

**Paul Fitzgerald** · 9-Dec-2006, 09:06

Bill,

All of the above. The end caps have little gaskets that may have dried out. If the caps don't hold an air tight seal the shutter can act like that. Try removing the caps, add a drop of oil to each, let it sit for a minute to swell the gasket and reinstall them. It might solve your problem.

Good luck with it.