F. Deckel-Munchen Compur Shutter Problem

[Matt Hall]

I have a 1931-35 KW Patent-Etui with a F. Deckel-Munchen Compur shutter with a Tessar 135mm f/6.3 lens. Shutter was completely locked upon arrival so I took it apart yesterday. Problem is with the slow speed escapement. Apparently someone before me attempted to repair this lens and removed the wrong screw on the slow speed escapement. The top plate of the unit came loose and all three gears slipped out of their axle holes. One of them was actually lying inside the case next to the escapement. After a lot of head scratching I figured out where each gear went and got them reinstalled correctly. The issue is with the center gear which is spring loaded. I know it has to be tensioned but how much do I tension it? Should I wind the spring all the way in or does it need to have a specific tension for the shutter speeds to be accurate (like x number of turns)? Any help would be appreciated. By the way, the spring seems to be in good shape and is not tweaked or bent as far as I can tell. Thanks.

 

[Matt Hall]

Well, it looks like the main spring has come loose from the center gear axle. I have been turning the gear but the spring will not tighten up. Whoever worked on this before must have over tightened the spring and it broke. Looks like I need to find another shutter. Thanks.

 

[Donald Qualls]

You may have discovered what happened to the rim-set Compur with one of my 13.5/4.5 Tessar lenses in it -- right before someone previous to me removed all the actual shutter parts and left it as a barrel with aperture.

Fortunately, my Speed Graphic has a fully functional focal plane shutter, but that doesn't help you with your Patent Etui.

Do be sure to preserve all shims from the mounting of the shutter to the front standard; you should, in theory, be able to mount the lens you have into any shutter the same size/type and install it with the same shims in the same places, and get your infinity focus to match. I can tell you from experience that this may not be the case with another lens of the "same" focal length; I tried to replace the 13.5/4.5 Radionar I had with a 13.5/4.5 Xenar in the same shutter and found I couldn't focus to infinity -- and the infinity stops on that camera aren't readily adjustable.