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Msiegel
Tinkerer
Username: Msiegel
Post Number: 6
Registered: 03-2008
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, April 04, 2008 - 07:33 am: | 
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I have a Voigtländer Prominent (35 mm RF) which was completely blocked. No winding, no shooting no nothing. The cocking lever was blocked at the almost cocked position. I wondered if the winding mechanism blocked everything or something inside the shutter.
After a lot of research (including the sites of Rick Oleson and Daniel Mitchell) I decided to open the shutter and it proved to be right decision.
Attached to the cocking lever there is a part which has been described as a bird's head in an earlier posting in this forum. The right hand side of this part (the end closer to the speed gear rack) got caught in the grooved curve approx. at the point were the speed gear rack is fixed with a screw.
From that earlier posting I mentioned I learned that the "birdhead" should be spring loaded - it now looks like that spring either is broken, loose or lost in my camera.
Before I take out the cocking rack I would like to know what that spring is supposed to do and what the "birdhead" does in general. Which way is it supposed to travel? Now when cocking the shutter is follows the curved groove and giving it a little help it finishes it's way until it clicks in. Is it supposed to take the same way back when the shutter is released? I also see a cut close to the shutter center so maybe it should go back that way?
Thanks in advance for your help.
And before someone mentions it: Yes, I know the Synchro Compur is a complex and tricky thing - not the best choice to begin with repairing - but the camera is a family piece and I want it back to live.
So thanks again and regards
Martin
P.S. Sorry if my vocabulary is sometimes a little bit strange when speaking about parts - English is my second language. |
Markus
Tinkerer
Username: Markus
Post Number: 37
Registered: 08-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, April 05, 2008 - 09:02 am: |
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If I understand your question correctly, then what you call the bird head has at one end a little hook that will hook into a notch in the cocking lever ring when the shutter is cocked and will keep that cocking ring in its cocked position. The other end of the 'bird' is pivoted by the shutter release lever which, when tripped, disengages the hook at the other end of the bird lever and sets the shutter mechanism in motion.
- Markus |
Brianshaw
Tinkerer
Username: Brianshaw
Post Number: 24
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, April 06, 2008 - 02:59 pm: |
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In addition to what Markus said... that part has a small spring underneath it. It is generally the first spring to get displaced when a synchro-compur is taken apart. Yes, it is supposed to be spring-loaded. If you haven't lost the spring already, the positioning is not particularly intuitive (and not something easily described in text). Suggest you get yourself a synchro-compur manual. There are several vendors that sell them on ebay. |
Msiegel
Tinkerer
Username: Msiegel
Post Number: 7
Registered: 03-2008
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, April 07, 2008 - 02:12 am: |
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Hello Markus and Brian,
First of all thanks a lot.
To make sure what I was talking about here a pic:
http://members.aon.at/~msiegel/prominent/6_speed_selector_off2.JPG
Thanks again and regards
Martin |
Markus
Tinkerer
Username: Markus
Post Number: 38
Registered: 08-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, April 07, 2008 - 07:21 am: |
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Ok, I was thinking of another piece. Your bird head is indeed traveling correctly. The spring that you say is maybe broken, is supposed to be loose, when the shutter is not cocked (it gets loaded when you've set the shutter to its highest speed). It looks like, as if its bottom part has perhaps been caught in the main spring. It has happened to me a few times when I reassembled a compur shutter. When put that spring in, its bottom part should point toward the bird head in your picture. If it is caught in the main spring (the long one attached to the shutter cocking ring) the whole thing would behave kind of stiff.
If it is broken, I have a spare, if you need it. Let me know.
I have sometimes had to very lightly lubricate the groove that the bird head travels through to make things work smoothly. |
Msiegel
Tinkerer
Username: Msiegel
Post Number: 8
Registered: 03-2008
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, April 07, 2008 - 07:44 am: |
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Markus thanks a lot.
I understand that the big (loose, maybe broken) spring is the 1/500th booster spring which is only used for 1/500th.
So the only question that remains is if the "bird head" (does anyone know the correct word for it either in English or German?) is spring loaded as well? Or should it just move easily around it's axis which is connected to the cocking ring/lever?
And what does it really do?
Thanks in advance.
Martin |
Markus
Tinkerer
Username: Markus
Post Number: 39
Registered: 08-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, April 07, 2008 - 08:33 am: |
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Martin, the bird's head is attached to the bottom of the cocking ring and it is spring loaded. I found an image with Google:
http://www.kochi-med.net/moto/camera/camera_repair/brillant/compur/pic/DSCN5088. jpg
and the whole series detailing the CLA of a Compur shutter is here:
http://www.kochi-med.net/moto/camera/camera_repair/brillant/compur/index.html
(in Japanese). You will probably just need to take the cocking ring off, clean it thoroughly and perhaps very lightly lubricate its moving parts.
(ich spreche auch deutsch und kenne mich leider mit den englischen Fachausdruecken auch nicht so gut aus).
- Markus |
Markus
Tinkerer
Username: Markus
Post Number: 40
Registered: 08-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, April 07, 2008 - 08:40 am: |
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To answer your other question, what does the bird's head do?
I think, it engages the mechanism that opens and closes the diaphragm. When you cock the shutter, it travels in around the bend and thereby avoids opening the diaphragm. When the shutter is tripped, it travels back along a straight line and then engages the mechanism that opens/closes the diaphragm. |
Msiegel
Tinkerer
Username: Msiegel
Post Number: 9
Registered: 03-2008
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, April 07, 2008 - 09:50 am: |
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Thanks again Markus!
I had not found the links to the Japanese site with Google - wrong search string, I suppose. Very helpful indeed.
So a final (?) question before I start to work on the shutter:
If I understood you correctly the "bird head" follows the curve when cocking the shutter to avoid the blade driveing mechanism but it does not go back the same way when shooting?
Thanks and I'll let you know how I managed - but it might take a few days. |
Markus
Tinkerer
Username: Markus
Post Number: 41
Registered: 08-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, April 07, 2008 - 11:11 am: |
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I am almost entirely sure that that is how this thingy moves. I have a disassembled parts Seikosha Rapid (which is a copy of the Compur) at home and I will check it after work to make sure. |
Markus
Tinkerer
Username: Markus
Post Number: 42
Registered: 08-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, April 07, 2008 - 09:57 pm: |
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I checked, and the way you indicate on your photo is how the bird's head moves. |
Msiegel
Tinkerer
Username: Msiegel
Post Number: 10
Registered: 03-2008
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, April 08, 2008 - 01:18 am: |
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Markus thanks for all your help and efforts.
I will give the shutter a try and let you know ho the story ended.
Martin |
Msiegel
Tinkerer
Username: Msiegel
Post Number: 12
Registered: 03-2008
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, April 16, 2008 - 09:25 am: |
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Markus and everyone else who was kind enough to post - I have the Prominent working again (in a way).
Cause for the trouble was the "bird's head" it got stuck because of dirt - meaning it's spring was not strong enough to move it. This caused it's front end (direction of cocking) to get stuck in the curved groove. Due to the Prominents cocking mechanism the cocking lever could not move in any direction anymore.
Giving the complete cocking ring a good bath in Zippo lighter fluid freed the "Bird's head". So the shutter can be cocked an released again.
Times seem to be way off so I will have the to take the shutter apart again for further cleaning. Only thing broken is a tiny spring that engages the lever for "B"
Markus the booster spring works OK - but thanks again for your offer for a replacement one.
So thanks again to all of you
Martin |
