Voigtlander Prominent I Compur repair help

Kirks518 · Apr 21, 2015

The shutter on one of my Prominents needs some serious shutter help, but I can't figure out how to get into/open the shutter. The only screws I see are inside the back, which I would guess would remove the whole lens mount assembly. I just want access to the shutter innards. Anyone know how?

The only thing I can see is a retaining ring type brass ring near the opening, but I couldn't get it to budge with decent force using a proper spanner wrench.

gone · Apr 21, 2015

I'm surprised that the retaining ring you mentioned won't come off Kirk. From all appearances, you should be able to put a spanner into those notches in that ring you mentioned and spin it off. Whether that gives you access to inside the shutter or not I couldn't say. I've been inside a lot of those types of shutters before and never had any problems opening them up, so maybe it's just frozen and needs a few drops of penetrating oil on the edges to set for a day or two before it comes off. Did you try heating it up w/ a hair dryer? Probably 80% of the time, my cameras like yours w/ those types of shutters were fixed by giving the shutter a good douse of lighter fluid and/or high test alcohol (not the usual watered down stuff, but the stuff w/ a high alcohol content around 91% that Publix sells) at the part where the shutter speed selector ring meets the rest of the shutter surrouind, and letting it soak into the shutter internals. It's probably dried lube in there. If something is actually broken, of course that wouldn't help.

From my years as a machinist, I know that a few good taps w/ a small hammer onto a screwdriver pushed into those cut outs, along w/ the penetrating oil setting for a few days, will usually get something unfrozen. Even those Agfa Isolette shutters w/ the green gunk that freezes up the focus came free once I soaked them in that alcohol for several days. My last one was so stuck, it seemed welded into the helical threads, but after 3 days of soaking in the alcohol it unscrewed w/ just my fingers.

durr3 · Apr 21, 2015

Kirks518 said:
The shutter on one of my Prominents needs some serious shutter help, but I can't figure out how to get into/open the shutter. The only screws I see are inside the back, which I would guess would remove the whole lens mount assembly. I just want access to the shutter innards. Anyone know how?

The only thing I can see is a retaining ring type brass ring near the opening, but I couldn't get it to budge with decent force using a proper spanner wrench.

What is wrong with the shutter?

Brett Rogers · Apr 21, 2015

There is an excellent repair manual on CD available on eBay and reasonably priced. It will cover this query as well as many more. urmecking is the seller's ID. I'm not associated with him, just a satisfied customer.

shutterfinger · Apr 21, 2015

http://benoit.suaudeau.perso.neuf.fr/manuels_rep/obturateurs/Compur-shutter-repair-manual.html
The ring in the center with the 2 notches 180° apart is a retainer ring. Unscrew it with a spanner and note position of each piece as you lift them off.
Your specific camera is not listed in the linked manual but some Viogtlander models are. The shutter will be one of the base shutters listed in the manual adapted to this camera.

Kirks518 · Apr 21, 2015

shutterfinger, thanks for the link. I've had it as an open window for a few weeks, but like you said, that specific shutter isn't there, but I figure once I open it, there should be similarities.

momus and durr3 - both sets of blades open and close fine, but I have soaked them with lighter fluid anyway. No change. What the problem is, is when the camera cocks the shutter, the 'arm' that gets cocked doesn't stay cocked, and slowly trips, like it was on the self-timer. The speeds seems about right, but I just can't get the shutter to stay in the 'ready' position.

Here's a short clip, rather then trying to describe it (you can't see the shutter blades open, but they do) -

[video=youtube_share;qrOtUipJjDE]http://youtu.be/qrOtUipJjDE[/video]

Greg Heath · Apr 22, 2015

I would contact Jurgen at Certo6.com

He works on these brands. The Compur shutter is difficult to set properly. I rebuilt one in a Rolleicord.

Greg.

Kirks518 · Apr 22, 2015

The shutter was set to 1/250, so it was probably too fast to see it open in the video, but it does.

Greg, thanks for the link, I'll drop him a line, but based on his average prices, it probably won't be worth it to me.

Brett Rogers · Apr 22, 2015

That manual I mentioned.
http://www.ebay.com/itm/36127739389...l?_from=R40&_sacat=0&_nkw=361277393892&_rdc=1

Disclaimer: I don't own a Prominent, yet (I'd really like to) but I have other Voigtlaenders and have worked on a lot of Synchro Compurs in various cameras. Having said that:
Two things come to mind. You said the shutter is set to 1/250 in the video, but I can hear an escapement running down after you manually cock the lever. If the speed is set to 1/250, it can only be the self timer escapement, surely? I wanted to mention this so you're aware of it (in the event you're not). Are you setting the timer intentionally? Secondly, the shutter will need to be opened up, because it has some internal issues. Perhaps the main spring pinion has jumped a tooth on the cocking rack (possible if the retaining ring for the front of the shutter was loose, or (more likely, I think) some numpty has assembled the shutter with the timing a tooth off. This will enable the shutter to run off at basically the right speeds and sound like it's working OK, except that, with many cameras using a variation of these shutters, it won't quite move the gear enough to latch up. Of course it is also possible, I suppose, that the wind mechanism of the camera is not fully actuating the shutter however this would be reflected by incorrect frame spacing, and, besides, you're having the same problem when you cock the shutter manually which suggests it is unlikely. Without actually having worked on a Prominent (yet) that's the best I can do, however I would be investigating those sorts of possibilities in the case of a shutter that basically functions but fails to hold.
Cheers,
Brett

Greg Heath · Apr 22, 2015

Here is a link to my Rolleicord IIe that I rebuilt a couple of years ago. It was a Compur shutter.

http://flic.kr/p/bbPcAr

Pan through the images. It may help you when you get it open.

When I started doing camera shutter rebuilds I was afraid I was going to bugger it up. Have some place where you disassemble it in order and if you have to walk away and leave it for a couple of days fine. I use ice cube trays to keep track of the multitude of screws. Every step along the way I shoot a photo with my phone. That way when you start to put it back together you don't become confused about which part goes where. I also cover glass lenses with gaffers tape in the event my spanners slip.

Greg.

Greg Heath · Apr 22, 2015

Also go on Flickr dot com and track down "Hans Kerensky"

He is a a great resource. I consider him to be Obi Wan Kenobi of the repair world.

Kirks518 · Apr 22, 2015

Brett - The shutter is working (seemingly) correctly at all shutter speeds. 1/250 just happens to be where it was when I made the video.
I think you are correct, in that a gear/tooth or something just isn't catching. When using the film advance, it'll only 'pushes' the lever to the red dot, which is correct, but the lever isn't 'catching' on whatever it's supposed to catch on inside. I think that's my whole problem. The manual says not to use the self-timer with B or 1/500, and I almost wonder if that's what someone did in the past, but I really don't know what the ramifications of doing that would be.

Greg - Great links, thanks. I can see myself referring back to Hans' info quite often.

I applied some liquid wrench to the retaining ring, and so far, still no luck getting it to budge. The thought of using a hammer isn't a pleasant one, but it may come down to that. I'm just worried about the soft brass (unless its bronze) getting damaged.

shutterfinger · Apr 22, 2015

The difference between a Compur and a Synchro-Compur? the Synchro in the name.The design changed over the years as improvements in mechanical design came about and precision refinement improved.
Synchro refers to flash sync synchronized.

Early Compur has a spring actuated paw attached to the setting ring that catches on a dog in the case to hold it set.
Synchro-Compur has a lever spring loaded to catch a dog or pin holding the setting ring in the set position. On this camera the setting hold lever may be external of the shutter. Dried lube or gunk build up is preventing it from working.
Gunk: micro fine metal particles from normal wear, dust, contaminates from the air in the environment the camera has been in, and oxidized residue from lubricants used in the shutter mixed together inside the mechanical assembly.

Greg Heath · Apr 22, 2015

Yes. See my photos of the gunk I got out of my Compur shutter. Truly amazing.

If I was you original poster, I would send this out for a professional CLA. This camera used is like $1000. Sometimes you gotta bite the bullet and pay $$ for stuff. I'm pretty good at doing my own work but I would send my Hasselblad out for service and not work on it. Like the RB67, piece of cake. I bought it cheap so I could work on it.

Your camera very expensive paperweight if you break it.

Brett Rogers · Apr 22, 2015

Re: timer and 1/500 or Bulb. Your Prominent must have the older version of the Synchro Compur which is really a Compur Rapid type with booster spring for 1/500. These will jam if timer and 1/500 or Bulb set, timer cannot be used with these speeds. Also ensure you only set speed to or from 1/500 before shutter is cocked. Later Compurs lack the booster and can use timer with 1/500.
Hans is a good guy. I like him a lot, he's friendly and always helpful. A good bloke.
Cheers
Brett

Kirks518 · Apr 22, 2015

So I finally got the shutter open. If I had to guess, I think someone was in there before, and mucked up something. It still seems to just be something that isn't catching, but for the life of me, I can't figure it out.

Maybe over the weekend when I have more time I'll dig deeper, but that'll be a project. I do have another Prominent that has no issues, and I'm inclined to open that one up to see if I can find a difference.

Greg Heath · Apr 22, 2015

Every used camera I buy, I just go slow, take a bunch of photos, and then just study how it works....take some more photos, and then I slowly disassemble the shutter, and take the shutter leaves out. I always make sure I don't disassemble the aperture because THAT truly is a nightmare to reassemble. Then all the pieces including the shutter body gets put into my Harbor Freight Tools Ultrasonic cleaner. It's filled with White Gas (Naptha). I run it for 15 minutes with it's integrated top and all the crap that is sticking on the shutter comes off like magic. It was the best tool I bought. I love that thing.. Then dry and reassemble. Oil nothing except the timing escapement spindles with NyOil. The Compur shutter timing is set by adjusting the sliding timing escapement (the thing that's the shape of a banana-no it isn't yellow) at the 5 O'Clock position closer towards the center or to the outside before tightening the holding screw. Here is the link to my album. I'm not sure if this is the same shutter as yours...hopefully it's close. https://www.flickr.com/photos/kb2qqm/sets/72157651667174417/

Greg

Oh, yes, do not put any lens rings with painted writing into the ultrasonic cleaner, as it will remove the paint.

Greg Heath · Apr 23, 2015

Compur Shutter Repair Manual

I have used this guy for manuals before. Good stuff.

Check out Compur Shutter Repair Manual: All Models c1968 http://www.ebay.com/itm/Compur-Shut...1968-/370808645944?roken=cUgayN&soutkn=cMSed9

Greg

Punkinhed7 · Jun 13, 2016

Kirks518 said:
So I finally got the shutter open.

Sorry to resurrect an old thread, but do you by any chance have pictures you took along the way? I'm currently trying to get into one to see if i can resolve a stuck shutter issue and am not quite sure where to go after removing the retaining ring/lens mount/shutter speed ring. Thanks.

Greg Heath · Jun 13, 2016

The Compur Shutter is not a shutter you shoukd be learning on, because you will end up with a box of parts. If this is a camera you care about, send it to Jurgen at Certo6.com. For under $200 you can have a perfectly functioning camera again. Do not take apart the back of the shutter because all of the Aperture blades will come apart.

shutterfinger · Jun 13, 2016

The Compur Service manual linked in post #5 should cover the shutter and special mount. If it is not directly listed then the various mounts and shutters will be very similar to what you have.
A Compur shutter is a 7 on a scale of 10 for experienced shutter repair persons not familiar with Compur shutters and anyone not familiar with shutter repair may find them to be an 11 or higher on the scale of difficulty.

remarkability · May 3, 2018

So, I have a Prominent I with film advance lever. Everything is locked up making me think there is a mechanical issue. The film advance lever does not advance, the shutter button does not fire the shutter, the shutter cocking lever/self timer knob is at the top 12 o'clock position and will not budge. Cannot find any leads on what to do online. I just don't know if it can be "unlocked" by the owner. Any insight appreciated.

choiliefan · May 3, 2018

Check if the self-timer lever is cocked. If so that may be part of the problem. Not much help, i know...

Voigtlander Prominent I Compur repair help

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