Dial set Compur issue

[BarryS]

I recently bought a Schneider Xenar Typ D f/3.5 in an old dial set Compur shutter. The shutter seems to work except for one problem--the cocking lever is missing because it sheared off the screw heads that attach it to the cam that rotates and cocks the shutter. I have another broken Compur shutter with the lever still attached to the cam and would like to swap the cams so I have a fully functioning shutter. The cams appear to be the same part, but I'm wondering if they're likely to be interchangeable and if anyone has experience removing the cam and can tell me about the amount of disassembly required. Thanks.

[BrianShaw]

I don't exactly know. But this might give you some clue as to difficulty of opening. Hopefully reassembly is as easy as I imagine opening an disassembling will be.

http://www.davidrichert.com/dial_set_compur.htm

[BarryS]

Thanks Brian--that's very helpful as far as opening up the shutter. I guess I'll try opening up the trashed shutter and see if I can remove and replace the cam without the whole thing flying apart.

[BrianShaw]

I've never had a shutter "fly apart" but I've certainly had springs do that. Watch very carefully for spring placement before you start taking stuff out. I imagine that the cocking lever is directly attached to the strongest spring in the shutter. Knowing htat even tiny springs can go a fair distance and get lost... I imagine that bigger springs can go farther!

[BarryS]

My definition of "flying apart" goes down to a single piece flying out that can't be found or replaced without professional assistance. I figure if I have problems with the broken shutter, the fixable one will immediately go to Carol at Flutots or I can always continue to cock the shutter with a hemostat around the cam--my current method.

[Glenn Thoreson]

The Dial Set Compur is about the easiest shutter to work on ever made. The parts should interchange between shutters of relatively the same size.
Remove the screw in the speed dial and lay the parts out in the order they go back, paying special attention to the position of the pin and it's hole in the silver disc. Remove the 3 screws from the trip lever and set it aside. Remove any aperture scale screws and the scale plate, if it has one on the face. Remove the two screws from the front cover. You're in! It will be obvious at that point, what you need to do to change the part. If I remember correctly, it will come right out after you remove the center screw. Take digital pics as you go for reference. Good luck.

[Paul Fitzgerald]

BarryS,

the cam you are looking at is usually the last piece removed. it is attached to the main spring inside of it. when you release the stop you should count have many turns it takes to release so you can pre-set it when you assemble it. the main spring is a long flat coil and should not jump out but it fits to the cam and body ends with a little finger into a slot. it's not fun to change out and easy to put it in upside down.

Have fun with it.

[BarryS]

Gentlemen, I believe I've located the main spring.



Paul--I wish I'd read your post before I removed the cam, but in retrospect, it makes sense that the main spring would be coiled up inside the cam. Fortunately this is my junk shutter, but it's not going to be easy to put in the new cam and get the spring coiled properly.

[BrianShaw]

Barry,
That looks just like a clock or watch spring. I've never seen one like that in a shutter before (but, then again, I've never overhauled a dial-set Compur). Does the post screw into the shutter body? If so, it might be possible to remove it and load the spring onto the shaft and cam as an assembly. For clocks there are "spring winders" to help tension the spring for re-insertion into the barrel. For a lighter spring like this one you can probably wind it on by hand. Then it would be possible to install the cam-spring-post assembly into the shutter. All of this depneds on the ability to remove the post, of course.

If nothing else, you now have a great opportunity to clean and lube the spring.

Good luck. When I get into one of these situations I sweat profusely and vow repeatedly that I'll never take apart another camera shutter! (After fiddling, though, I've generally had enough success that I forget about the vow. If I didn't say it already... good luck!

[BrianShaw]

Check out course # VL-9... I'm tempted to spring for it! (no pun intended.)

http://www.vintage-camera-repair.info/lessons.htm