Who Repairs Contax I's ?

[Erik van Straten]

When I first saw the question, my initial answer was "No-one in their right mind". I didn't post this because it would have been totally unhelpful. However, having now read the thread, it seems I was pretty close to right.

Cheers,

R.

Thank you very much, Roger, for this fine compliment. That post would have been unhelpful indeed.

Erik.

 

[Highway 61]

When I first saw the question, my initial answer was "No-one in their right mind". I didn't post this because it would have been totally unhelpful. However, having now read the thread, it seems I was pretty close to right.

Cheers,

R.

You could very well have posted this. It would have been as helpful as whatever you post actually.

Erik : congrats for the repair and the very nice pictures. As Brett mentioned, you may have to slightly bend the clutches in which the ribbons slip if you used some silk ribbons a bit thinner than the original. This may solve the capping problem at the highest speeds. I wouldn't add some tensioning to the bottom roller drum spring. On many Contax II which I repaired, that spring was dead because people had tried to solve a capping problem by overtensioning that delicate spring. Fortunately the Kiev part is 100% identical and easily available - not too sure about the Kiev part fitting the Contax I shutter, though.

 

[Erik van Straten]

As Brett mentioned, you may have to slightly bend the clutches in which the ribbons slip if you used some silk ribbons a bit thinner than the original. This may solve the capping problem at the highest speeds. I wouldn't add some tensioning to the bottom roller drum spring. On many Contax II which I repaired, that spring was dead because people had tried to solve a capping problem by overtensioning that delicate spring.

Thank you, Nicolas, your post is very helpful!

My problem now is what you exactly mean with "clutch". I will reread the posts of Brett. I can give this suggestion a try.

Erik.

 

[Erik van Straten]

Although it was running reasonably well, after adjusting the clutches it began to sometimes not latch up correctly, particularly when released upside down. You need to test the camera in various positions, I think, to be really sure it will continue to work, because sometimes gravity and friction may manifest certain problems only if a camera is fired in a particular orientation. The curtains would latch OK with the camera held normally, but upside down gravity began to brake the second curtain at the end of its run slightly, because it would cap the gate, but not quite latch fully.

Brett, in the case of the Contax I v5 this will not happen so quickly because the shutter is made of very light aluminium. The lamellea of the shutter of the Contax II are made from brass, much heavier.

Erik.

 

[Sarcophilus Harrisii]

Brett, in the case of the Contax I v5 this will not happen so quickly because the shutter is made of very light aluminium. The lamellea of the shutter of the Contax II are made from brass, much heavier.

Erik.

Thanks, Erik, I was not aware of this, not having delved into a Contax I. I'm not actively looking for one, either, but would certainly be interested in seeing inside one, because as the starting point for the Contax series, it might add to my understanding of their design, operation, and evolution. I've tentatively arranged to purchase another Contax next month anyway, but it is another II, a one owner B prefix 1936 example with a collapsible Sonnar. In the meantime, I have another one here to do for someone else, a Contax III, so I am not done with Contaxes yet. 😉

The clutches I mentioned are also sometimes referred to as the "buckles" in the top plate of the first curtain, that the ribbons are fed through, before being stitched to the ribbon drums (or after, I suppose, depending on which end you do first, I've always started at the bottom when doing ribbons actually). As Highway 61 said, these may need to have their clearance reduced with thinner ribbons (at least the II and III ones do). If there is too much clearance, the fast speeds may be off. At the high speeds, essentially, the ribbons and the first curtain should traverse the film gate in unison, as one. But if the clearance is too big, there will be insufficent friction to take the first curtain "along for the ride" with the ribbons, and then the ribbons can slip through the clutches, and this is going to bring the second curtain with them, which will reduce the gap leading to incorrect exposure (likely underexposure because of the smaller gap). Or it can cap the gate completely, or lead to variations in exposure across the gate (with exposure decreasing towards the bottom of the camera as the second curtain gains on the first). The larger the clearance is above optimum I think the more likely it would be that the shutter would cap off altogether.

This information is of course all based on my experiences with the II version and as you have pointed out there are some important differences between the original and later and I do not profess to have much knowledge of the original type at all. But hopefully enough of the details above will be transferable to the older model to be of some help anyway? Unlike some other commentators here I cannot claim any special expertise with the Contax shutter, having only worked on a couple of examples of it, albeit successfully. I've gathered the above from working on and observing the shutter in operation and reading anything I can find about its peculiarities (of which, there are many!).
Cheers,
Brett 🙂

 

[Highway 61]

Erik and Brett, here is a link towards an old thread created eight years ago on this forum, but the informations it contains still rule.

The Arsenal ribbon is too thick to be usable in any Contax shutter, but the Aki Asaki ribbon is not only thinner than the Arsenal ribbon, but also thinner than the original Zeiss silk ribbon, so the workproof technique of slightly adjusting the clutches do apply if you use some Aki Asahi ribbon in both a Kiev shutter and a Contax II/III shutter.

I have to admit that I'm still clueless about this technique applied to a Contax I shutter. But, it may work.

http://www.rangefinderforum.com/forums/showthread.php?t=55914

 

[Sarcophilus Harrisii]

Erik and Brett, here is a link towards an old thread created eight years ago on this forum, but the informations it contains still rule.

The Arsenal ribbon is too thick to be usable in any Contax shutter, but the Aki Asaki ribbon is not only thinner than the Arsenal ribbon, but also thinner than the original Zeiss silk ribbon, so the workproof technique of slightly adjusting the clutches do apply if you use some Aki Asahi ribbon in both a Kiev shutter and a Contax II/III shutter.

I have to admit that I'm still clueless about this technique applied to a Contax I shutter. But, it may work.

http://www.rangefinderforum.com/forums/showthread.php?t=55914

Thanks, I think I may have this one bookmarked already but will check that. If I am not mistaken, measurements were taken by someone and posted on RFF previously which advised the A-A ribbons are about 50% of the thickness of original ZI material.

The last II that I worked on had one original Zeiss ribbon still on the rewind side of the shutter and one of an unknown purple material or origin on the wind side. No surprises that the Zeiss one had begun to fail. Who goes to the trouble of disassembling one of these only to change one ribbon? Madness. They'd mangled the clutches a little, too, fortunately, not terminally.
Cheers,
Brett

 

[Erik van Straten]

Erik and Brett, here is a link towards an old thread created eight years ago on this forum, but the informations it contains still rule.
http://www.rangefinderforum.com/forums/showthread.php?t=55914

Thank you, Nicolas, for digging this up. Very informative.

erik.

 

[Gregm61]

Thanks, Erik, I was not aware of this, not having delved into a Contax I. I'm not actively looking for one, either, but would certainly be interested in seeing inside one, because as the starting point for the Contax series, it might add to my understanding of their design, operation, and evolution.

This guy has some detailed images of digging into a Contax I..

http://www.zeisscamera.com/services_overhaul-cI-shutter.shtml

 

[Grytpype]

The Arsenal ribbon is too thick to be usable in any Contax shutter, but the Aki Asaki ribbon is not only thinner than the Arsenal ribbon, but also thinner than the original Zeiss silk ribbon, so the workproof technique of slightly adjusting the clutches do apply if you use some Aki Asahi ribbon in both a Kiev shutter and a Contax II/III shutter.

I use an engineering micrometer to gauge the thickness of a ribbon, which is obviously not an ideal instrument for a material of this nature, and takes no account of the density or weave, but it ought to give some sort of comparison. Using a one-inch mike, genuine Contax II/III ribbon generally measures close to .011". The Aki Asahi measures .005".

I'm not at all sure about the suitability of 'Arsenal ribbon' for Kievs. I have this ribbon from two sources. They appear to be identical, except that one measures .016" on the mike, and the other .015". The ribbons in a 1974 Kiev measured .0135, and in a 1967 Kiev I re-ribboned recently, the original ribbons measured .0125". I opened the friction slots slightly to use the new ribbon.

A thickness of .0125" is almost Contax territory. A Contax II I rebuilt had already had the ribbons replaced with ribbon .012" thick.

How similar is Contax I ribbon to the II/III variety?

 

[Erik van Straten]

How similar is Contax I ribbon to the II/III variety?

Foolishly enough I trew away the pieces that came out mine. They were 3mm instead of the 4mm of the Aki Asahi stuff. It was much thicker and had a grayish/yellowish/greenish color. I've never seen Contax II ribbons, so I can not make a comparison.

Erik.

 

[Highway 61]

I've never seen Contax II ribbons, so I can not make a comparison.

The color of the original Contax II ribbons was a mix of dark green and 18% Kodak grey.

"Feldgrau" would be 100% accurate, although that word is of some nasty heritage.

Their width is 3mm.

 

[Erik van Straten]

How similar is Contax I ribbon to the II/III variety?

Grytpype, just by accident I found a small piece of the ribbon from my Contax I v4. If you PM me your address I'll put it in an envelope and send it to you.

Erik.

 

[Grytpype]

Thanks Erik.

Not sure whether any information I can provide will be worth the cost of your postage, but have PM'd you.

Steve.

 

[Dralowid]

From memory the ribbons in my Super Nettel are black, or look like they were originally black. It works (with regular dosings of lighter fluid).

I have two Contax Is. Nether have slow speeds. One works happily across the range but requires significant effort to wind on and tension the shutter. The other (dimple) is much lighter but can only be relied upon at 1/200ths.

They are fun.

I understand Roger Hicks' comment but do not agree. Keeping an old and unreliable piece of machinery working can be satisfying, it may not be entirely logical but then no one questions all those who are trundling around in ancient cars that are frankly, on today's roads, not fit for purpose.

Each to his own.

 

[Erik van Straten]

They are not difficult to repair. Their construction is like an old radio.

Erik.

 

[Roger Hicks]

. . . I understand Roger Hicks' comment but do not agree. Keeping an old and unreliable piece of machinery working can be satisfying, it may not be entirely logical but then no one questions all those who are trundling around in ancient cars that are frankly, on today's roads, not fit for purpose.

Each to his own.

Sure. It's something you do for love. But paying someone else to do your loving for you...?

Cheers,

R.

 

[Highway 61]

Sure. It's something you do for love. But paying someone else to do your loving for you...?

Sure. People ready to pay someone qualified else to perform some good restoration job on something old and fragile they've got attached to, at the point of loving it, are stupid aren't they.

This is why I recently paid someone who was eventually successful at repairing my small all-brass Zenith alarm clock made in 1914 and in which the main spring plus some gears were broken. Two other repairmen had told me what you're basically telling about the Contax I. The third one saw things differently. He got the job and the money. And I got my lovely Zenith back and working. How dumb.

 

[Erik van Straten]

I really do not see why people think that a Contax I cannot be repaired. Yes, there is a lack of parts, but that is not strange for a 80-year old camera.

Yesterday I repaired a Contax I v7 that had a shutter problem. The shutter opened all by itself when the speed was changed and the shutter was in a tensioned position. After a couple of hours study I noted that the eyes on the top of the flap that grabs the first curtain (by its small hooks in the corners) where deformed, bent. Because of this the flap was lifted by the touch of the ribbons of the curtain behind it and so the shutter went open. Doubtless the deformation of the eyelets of the flap was caused by an earlier attempt to repair the camera. When noted the problem was easily solved.

The ribbons of this camera are in a perfect state.

The camera was written off. It came to me for a silly price, with a near mint nickel Sonnar 50mm f/1.5 mounted (100% perfect glass).

It is a superbly made camera. The lamellae are made of brass. I don't think that a Contax II is better made. Better designed, yes, ergonomically. The v7 has the same rangefinder as the Contax II I think.

I found only one weak spot on this camera. The three screws that hold the nickel ring around the speed setting knob are made of soft brass. They often need to be retightened. Their heads are easily damaged. I want to replace them with steel ones.

Erik.

 

[Highway 61]

The three screws that hold the nickel ring around the speed setting knob are made from soft brass. They often need to be retightened. Their heads are easily damaged. I want to replace them with steel ones.

I still have some small steel spare screws in a box. If you can mail me (with a close-up pic) their threads gauge, total length and head type, I may find some for you, Erik.