Contax lla ultrasonic cleaning

[Kevcaster]

OK A strip of consistently exposed negs from 1 second through to 1/500. Sadly an unexposed 1/1250, actually under exposed with an unexposed band through the middle. The negs where the self timer was used have a band of over exposure of about 2 mm across the top of the picture, any ideas? Still fully usable so far.
I'm going to tackle my llla but cannot see how to get into the top it appears to have different fixing regime to the lla. All advice always welcome.
Kevin

 

[Vickko]

Great work !!!!

 

[Highway 61]

OK A strip of consistently exposed negs from 1 second through to 1/500. Sadly an unexposed 1/1250, actually under exposed with an unexposed band through the middle. The negs where the self timer was used have a band of over exposure of about 2 mm across the top of the picture, any ideas? Still fully usable so far.

Give it up with 1/1250 and be happy with what you got.

As for the selftimer : it's the dumbiest design ever, actually the selftimer isn't a genuine one but something odd first holding the shutter curtains once they've been fired with the regular shutter release, then letting them go when the selftimer escapement ends its journey. This enhances the hesitation problem of the first shutter curtain. As a result you get uneven exposure at speeds of 1/250 and slower, and blank exposures at 1/500. Don't even think of having the camera work at 1/1250 if you use the selftimer, even if it occurs that you get a working 1/1250.

There is a possible remedy : the trick is to move up the whole selftimer unit on its chassis by playing with the two screws which hold it in place, and then tightening the screws very much, so that the darn thing remains located a bit upper on its chassis than where it's designed to stay, and like this it stops the shutter geartrain when the first shutter curtain has moved the least distance possible.

If you want to give it a try, you're in for taking the camera apart once and again.

Yet, this is the same as for the 1/1250 : it might work for a while, then the problem may come back ater the "shelf test" period.

Best thing is not to use the selftimer but for speeds of 1/50 and slower, if you absolutely need it (which is seldom the case afterall).

 

[Kevcaster]

Yes I am going to accept the loss of 1250. Also the flash sync, I have rarely ever used flash and when I do, make the same conclusion - it killed the picture. I can see the cams and levers doing their work but do not have special flash cables to test the system.
I use self timers quite often and once the llla is finished I will try your method for the position adjustment of the escapement, makes good sense. I have looked at this on the llla and have it set so that the catch allows minimum curtain movement.
I have no experience of other self timer mechanisms and guess that many work directly on the shutter release. This Contax setup appears to be the German precision engineers equivalent of putting a finger in the dam.
Kevin

 

[davidphillip]

selftimer

selftimer

The self-timers on all of my cameras work fine, up to 1/250. The original manuals caution against using the self-timer at 1/500 and 1/1250, so Zeiss knew what a weird system they had produced. I don't think repositioning the s-t will help for the two fastest speeds, though it does for 1/250 and down.
Rick Olesen has diagrams for how to disassemble the IIIa. Google him....

Regards, David

 

[Kevcaster]

Thanks David, I think I saw a previous post of yours that says this. I did't use the ST on the 2 fastest speeds I misled you in that respect. I have a copy of the manual and it clearly states that it will not work on those speeds. I guess that Zeiss engineers simply thought it unnecessary and left it at that.

Kevin

 

[Kevcaster]

A mild and brief panic set in earlier this evening when I realised that the speeds from 250 up we're not opening.
My first thought was that the shelf test had failed and the camera has reverted. Not so. The high speed paul was not engaging with the cam, the hair spring that flips it back into the engaged position on the cam on curtain 1 had come adrift. I think this occurred when I dabbed away some residue from the light oil applied to the cam when I opened up the camera to adjust the infinity lock.
Take care when working around these are fine components, this spring is just a few thou thick and a few millimeters long. The fine nature if these components requires that the other components they work with are equally fine and finely balanced, a triumph of design and precision. This also supports the idea that these mechanisms will only work with very light lubrication or none at all.
Kevin

 

[Kevcaster]

To return to the original question about ultrasonic cleaning fluid.
For the trim parts, knobs, various washers and springs, I used distilled water and the proprietary fluid that I imagine simply relieves surface tension. For the slow speed escapement, self timer and rangefinder gear train I used Naptha contained within in a film container immersed in the water bath. The parts sat vertically covered in the minimum amount of the solution required. I dried all of these components immediately in an oven at 50 degrees C . I suspended the rangefinder gear train to ensure the optics were clear of the solution and although some Naptha found its way there it was cleaned out fairly easily.
The slow speed escapement and self-timer assemblies had been flood cleaned but still gave up a good deal of debris. I'm pleased I did this.
Kevin

 

[Vickko]

My experience has been revised to:

"These mechanisms work with the correct amount of lubrication..."
I've had shutters fail when I fully clean them and run them dry, but then a tiny amount of the correct lube, and they work like a charm.

And yes, sometimes work with grease but fail with oil. Gotta get the "correct lube at the right amount".

Anyway, sounds like you are having fun. That is great, and thanks for posting the story.

<snip...... This also supports the idea that these mechanisms will only work with very light lubrication or none at all.
Kevin

 

[Kevcaster]

Second 'live roll' of FP4, speeds have settled dow. 1/1250th works and appears accurate! Their is an odd effect on 1/50th - looks as if the first curtain of the shutter slows momentarily as it parks leaving a thin unexposed band across the top of the image - the bottom of the film plane. Any ideas? The fault is intermittent .



The self timer is slow so I'm going to strip it one more time and re-clean it in the ultrasonic machine and re-lubricate the micro bearings.

This has been good experience and immensely rewarding. This camera was the practice for a later llla that I acquired. That camera has also turned out well with all speeds coming back to life and accurate consistent exposures. The self timer on that camera is vigorous so I have something to aim for.
Kevin

 

[Vickko]

wow, good work. Intermittent faults are a pain in the butt to track down.

 

[Kevcaster]

Ok after strip down, ultrasonic clean in Naptha and re-lube of bearings only with Mobius light watch oil, the self timer remains weak and will not pull free of the shutter retaining catch. It runs steadily to that point. I greased the garage where the catch locates. I'm considering that the catch return spring has lost it's strength, there is some stress in the assembly or finally that this should run dry.

The back had two minor 'impressions' from a knock or fall, not dents. I returned it to flat using a piece of 3mm thick leather cut to size and a leather rivet punch of convenient size. 3 knocks with a small hammer returned the metal to its original shape.

For now the camera works for normal purposes, I hope the 1/50th speed settles down and I will live with the dysfunctional self timer. I'm moving on to take pictures with it.
Kevin

 

[Kevcaster]

I'm enjoying carrying this camera, it is a beautiful object and good for picture making, I find I'm slowing down and anticipating shots a little more and feeling the '50's' vibe.
After 4 films I notice that the first two have multiple and inconsistent scratching to the emulsion side. Inconsistent in that they appear at different levels across the film frames and do not always stretch the length of the film. The 3rd film showed less and the last film just a little on the first few frames. This appears to me to be micro debris being shed from the shutter blinds, landing on the film and being dragged across the film guide at the end of the film gate. it seems to be diminishing as more films are exposed. I'm placing this here for future viewers who may also be baffled by the causes of scratching after servicing.
I had superficially cleaned the shutter blinds but clearly not thoroughly enough.

The self timer remains unusable for now and the 1/50th speed seems to either slow at the extreme of travel or, less likely, bounces, this is also diminishing with use - all other speeds fully functional. I'm pleased with this result.

 

[Kevcaster]

My experience has been revised to:

"These mechanisms work with the correct amount of lubrication..."
I've had shutters fail when I fully clean them and run them dry, but then a tiny amount of the correct lube, and they work like a charm.

And yes, sometimes work with grease but fail with oil. Gotta get the "correct lube at the right amount".

Yes Vickko this has proven to be the case. I opened up the camera and stripped out the self timer again. before trying another clean I thought I would first lube the obvious places. Sliding surfaces with lithium grease, the main hub with medium oil produced a better result but a slight improvement. I greased the spring retaining areas very lightly, still not right. The fix that finally freed everything up was to grease very sparingly the gears where they mesh. This had an immediate effect and the timer now runs vigorously and triggers the shutter freely.
DavidPhillip talked of Naptha creating a sticky surface finish and I speculate that this is what occurred with this unit, the grease providing the necessary freedom.