Contax I ribbons

[Dralowid]

A static exhibit for now.

IMG_2879 by dralowid, on Flickr

Here it is quickly put back together before I forget where things go and start losing the screws. The shutter fires, slow speeds etc seem to work, not surprisingly 1/1000 doesn't open. No matter, there are other problems.

I reckon it is to do with the gearing of film advance etc. When I wind the camera on after firing the shutter the dial does not come back to where it was originally, also sometimes it is necessary to lift the dial and turn it further to fully cock the shutter. Now I don't know what I have done to mess this up but for the time being, unless anyone has a good idea I think I will put the camera on a shelf and admire it.

At least we have all learned how to replace the ribbons and a make a Kiev lower roller fir a Contax I.

Thanks to everyone who has helped!

 

[Deklari]

Congratulations with your first picture! Looks very nice. What lens do you use?

I am very curious how you managed to adjust the high speeds, Deklari. Very interesting. Can you give us a small indication how you did it?

Erik.

I have used CZJ Sonnar 50/2 collapsible with red "T" (coated).
I will try to show what I did. I need a little more time for this.
I think Michael have similar issue too. Sometime I need to press a few times to make shutter fully cock. It is stop a 10-15 degree early and only after second press it turn further to fully cock. I have open the dial mechanism and spend a few days to understate how it work (still not fully understand).

 

[Deklari]

First look how it works.
For 1/1000 we need only 3mm distance
for 1/50.. maybe 3 cm
to make this distance ribbons were rolling with top curtain on the top roller. For lover speed winding mechanism make more ribbons tension. But at same time film moving always at same distance (green arrow).

 

[Highway 61]

First look how it works.
For 1/1000 we need only 3mm distance
for 1/50.. maybe 3 cm
to make this distance ribbons were rolling with top curtain on the top roller. For lover speed winding mechanism make more ribbons tension. But at same time film moving always at same distance (green arrow).

Your explanation and drawing repeats what has been told by Rick Oleson a long time ago :

http://rick_oleson.tripod.com/index-92.html

But you don't explain us how you managed to get the high shutter speeds work. Did you modify the synchronization of the two shutter curtains ?

Re. the problem of the shutter release button to be depressed again before you can wind in full that's a common problem of the Contax II shutter so it might be something similar on the Contax I shutter :

http://www3.telus.net/public/rpnchbck/changing%20shutter%20speeds.html

If the cams marked by the blue and yellow arrows on Russ Pinchbeck's photo have got sticky with grime over time, you may have to depress the shutter release button again so that you can wind in full.

 

[Deklari]

Your explanation and drawing repeats what has been told by Rick Oleson a long time ago :

http://rick_oleson.tripod.com/index-92.html

But you don't explain us how you managed to get the high shutter speeds work. Did you modify the synchronization of the two shutter curtains ?

Re. the problem of the shutter release button to be depressed again before you can wind in full that's a common problem of the Contax II shutter so it might be something similar on the Contax I shutter :

http://www3.telus.net/public/rpnchbck/changing%20shutter%20speeds.html

If the cams marked by the blue and yellow arrows on Russ Pinchbeck's photo have got sticky with grime over time, you may have to depress the shutter release button again so that you can wind in full.

I know it was published already. Just want to refresh.

Few critical steps there. First remember how "speed selector disc" was installed (central part has "square" connection that give 4 different combinations and only one is really working). Second, biggest "conical" gear could be push away from main shutter gear (what seat at 90 degree) and rotate to adjust top curtain moves (clockwise, if look from the front -will reduce distance between two curtains). I'm not professional, it work for me, but I couldn't warranty what this correct way to do it.

 

[Deklari]

this how it looks


In my case 1/1000 have to big "window". To reduce it, I have rotate gear 1-2 teeth clockwise.

 

[Deklari]

this how it looks from the front
(central axle has square connection)

 

[Deklari]

all parts

 

[Erik van Straten]

Fantastic that you went so far and that you share it with us, Deklari. Your explanation is quite clear. The drawings with the colors are great. Thank you very much.

I understand that when the openings between the curtains are not correct, someone must have changed the fundamental settings in the past. It can not happen by itself, so to speak.

Erik.

 

[Dralowid]

Erik,

I note you edited out a comment regarding the excellent designer of this great technical achievement...

However I would suggest that the shutter was designed by several people all at the same time, all in the same room but they never ever talked to each other.

It is as if they started everyday in the office with an argument as to who should make the coffee...

Deklari, your drawings are excellent, I am tempted to have another go at the camera but not just now.

Perhaps we should send you another fiendish device, maybe a Kodak Ektra or a Leicaflex SL would be a good challenge!


Michael

 

[Mr_Flibble]

I have some holidays coming up in a few weeks, I'll take a look at disassembling mine and possibly repairing/replacing the ribbons.

I'm sure this thread will be a big help.

 

[oftheherd]

Fantastic that you went so far and that you share it with us, Deklari. Your explanation is quite clear. The drawings with the colors are great. Thank you very much.

...

Erik.

I second that. This thread has given me an incentive to get back and finish my Contax II. All I need now is time. 🙁

 

[Deklari]

Fantastic that you went so far and that you share it with us, Deklari. Your explanation is quite clear. The drawings with the colors are great. Thank you very much.

I understand that when the openings between the curtains are not correct, someone must have changed the fundamental settings in the past. It can not happen by itself, so to speak.

Erik.

Thanks. I hope it can't happen by itself. This only part of the full story. There is another mechanism what keep winding knob locked when the shutter is fully cock. I still have issue with slow speed. "B" stop at the middle of the image window.

 

[Deklari]

Erik,

I note you edited out a comment regarding the excellent designer of this great technical achievement...

However I would suggest that the shutter was designed by several people all at the same time, all in the same room but they never ever talked to each other.

It is as if they started everyday in the office with an argument as to who should make the coffee...

Deklari, your drawings are excellent, I am tempted to have another go at the camera but not just now.

Perhaps we should send you another fiendish device, maybe a Kodak Ektra or a Leicaflex SL would be a good challenge!


Michael

Michel,
in your Contax it could be a different mechanism (without slow speed). However, as I understood, changing the "groups" ring will only change the gears to slow down curtains moving.

 

[Erik van Straten]

There is another mechanism what keep winding knob locked when the shutter is fully cock.

So you cannot change the speed when the shutter is cocked?

Erik.

 

[Deklari]

So you cannot change the speed when the shutter is cocked?

Erik.

Yes, but only for low speed. It work only in one direction. For example if shutter is cocked I can't change from 1/10 to 1/5 but I can from 1/5 to 1/10.. same for 1/2 and B.

 

[Erik van Straten]

Yes, but only for low speed. It work only in one direction. For example if shutter is cocked I can't change from 1/10 to 1/5 but I can from 1/5 to 1/10.. same for 1/2 and B.

Strange. It is normal that the "group ring" only turns in one way, anti-clockwise. The speed selector (pull and turn) should move in both directions, cocked or not.

Can you go with the speed selector in both directions when the shutter is released?

Erik.

 

[Deklari]

Strange. It is normal that the "group ring" only turns in one way, anti-clockwise. The speed selector (pull and turn) should move in both directions, cocked or not.

Can you go with the speed selector in both directions when the shutter is released?

Erik.

Yes I can. and more strange it work fine at any "white" numbers..
Actually shutter work fine if I sett 1/100 in "sport group" and just only change the group. It give me nice slow speed. I will test actual speed today.

 

[Erik van Straten]

Actually shutter work fine if I sett 1/100 in "sport group" and just only change the group. It give me nice slow speed.

This should also work on "B" ("Z"). In the sports group you'll get a clicking B and in the night group a slow buzzing B.

(In the sports group set the white dot on the spot of "B").

Erik.

 

[Sarcophilus Harrisii]

I second that. This thread has given me an incentive to get back and finish my Contax II. All I need now is time. 🙁

I have not tackled an original Contax but after following this thread with great interest, I think it is safe to say that a II will usually present fewer really hard issues. Usually it's just a case of replacing the ribbons and cleaning and lubricating the mechanism. Ribbon replacement isn't really that bad, Rick has some good information on his site. The main thing is to get some good silk ribbons (Aki Asahi work well) and ensure the clearance at the clutches or buckles is adjusted, because Ali's are durable, but thinner than original. I've done three IIs and have a III here I must attend to in next few days, and am confident of success with that. There's enough expertise here among owner/repairers that you can be assured of informed advice, and support if needed, so, go for it.
Cheers
Brett