REPAIR: Super Ikonta 532/16, Tessar 2.8/8cm & Compur shu

[stevemark]

Recently I was asked to examine a nice pre-war Zeiss Ikon Super Ikonta 532/16 which had issues with its shutter. In addition the Zeiss Tessar 2.8/8cm was fogged, and so was the rangefinder window and its "transmitter" glass on top of hte lens. The aperture was OK, but very stiff, and so was the focusing mechanism.



Since there's a lot of information about servicing the Compur shutters out there, I agreed to have a closer look at the camera.

[stevemark]

PART I: REMOVING THE LENS/SHUTTER FROM THE CAMERA

What should be an easy and straightforward step turned out to be the most difficult part of the whole adventure. Obviously other had tried before to separate the lens/shutter from the camera, as there were some marks on the retaining ring as well as on the bellows:


Removing the rear part of the lens was easy, but the retainer ring stubbornly refused to come out. Usually acetone is a good solvent to dissolve either the accumulated dirt or - if the thread was glued in - the glue. Not in this case. What came off was the black color, but not the ring itself. Prolonged soaking with many drops of acetone didn't work, and finally I decided to use small amounts of WD-40 penetrating oil. While such penetrating oil should be avoided whenever possible, it occasionally has helped me solving some otherwise unsurmountable difficulties. WD-40 usually is acting pretty quickly, but here it took a few hours (!) to soften whatever was inside the thread. The ring finally came off ...


... and I could remove the lens/shutter from the camera body:


There was also a very thin shim between lens and camera body:

Next: removing the lens and the rangefinder mechanism

[stevemark]

PART II: REMOVING THE LENS AND THE RANGEFINDER MECHANISM

Removing the rear doublet of the Tessar 2.8/8cm is easy. It's pretty fogged, as you can see:


To remove the black cover of the rangefinder mechanism, we have to extract these two screws PLUS andothet two smaller ones on the opposite sides of the cover:


The distance ring must be removed as well. It is held in position by three extremely small grub screws (about 1.2 mm diameter and 1.7 mm long):



The distance ring comes off:


The cover of the rangefinder mechanism comes off:



Now we can take out the single front lens of the Tessar 2.8/8cm which is used for focusing ("front focusing"):


It exposes the second lens, a negative lens which is quite fogged as well:


Extractin these four screws allows for removal of the entire rangefinder mechanism:




Shutter release (red arrow) and the double exposure lock (yellow arrow):


Double exposure lock removed:


Removing the second lens:



The second part of the double exposure lock is removed as well - it is just about 0.6mm thick, and the (pretty strong!) steel spring attached to it measures a mere 0.25mm in diameter:

[stevemark]

PART III: REMOVING SHUTTER COVERS AND APERTURE MECHANISM

First we can remove the aperture ring (aluminum) shown here - no need to loosen any screws, just carefully extract the ring:


Next is the star-shaped alu plate which keeps the aperture lever in position - two screws to remove:





Now we ca separate the black casing (which contains the aperture mechanism) from the shutter mechanism itself:


The aperture mechanism - three screws to remove:


The aperture blades are now free and can be cleaned with acetone (to remove any sticky grease):


Now the lower plate can be removed (two screws):



Next is the aperture lever which sits on the other side of the mechanism (this iimage is a bit misleading; the aperture housing should be shown "the other way round"; sorry fro that mistake):


The ring as well as the housing and - to some extent - the aperture blades were covered with some sticky, resin-like residues from the 1930s grease or oil. They were blocking the aperture mechanism. Cleaning these parts was easy; first some acetone, then detergent / water. For the aperture blades I did use ONLY acetone, no water!


The aperture lever is glliding on these surfaces; they should be cleaned and relubed with a tiny amount of grease:


The parts of the aperture mechanism after dismantling:


First steps to re-assemble the aperture mechanism:


The last blades are always the most difficult ones - if you group them sequentially like here on this image, you can assemble them pretty easily:


The only thing that remains now is to push them carefully into their final position:


Take the above part and put it onto a suitable round base (e. g. a lens friction toll with suitable diameter); then take the cover and place it in its correct position onto the assembled aperture blades. Connecting all the dots may require a bit of wiggling, but it usually works better than anticipated:


The aperture mechanism after cleaning and re-assembling:


The aperture mechanism now is moving smoothly and with very little resistance.

[stevemark]

I honestly kind of forgot about this one - however the story goes on, of course!

[Attila]

Fantastic guide!!

[stevemark]

Oh, I'm just processing all the images for the actual dismantling & cleaning of the shutter mechanism itself - will be published here soon!
That's really fun ... probably not too many people doing that any more (?!?)

S

[Attila]

[BrianSVP]

Huh, I've not encountered a Compur shutter before that uses punch-throughs rather than pegs for the pivots on the aperture blades.

Not a fan of the design, since if the tiny, fragile fins get bent, it can be extremely difficult to get the blades to stay in place.

This kind of design is used on a lot of Navitar/Elgeet cine lenses, making them a royal pain to repair.

EDIT: nvm, was viewing on a phone, and my aging eyes were playing tricks on me. Looks like they are indeed pegs.