Having picked up a Zeiss Ikonta for a real fantastic deal I felt compelled to see what makes it tick. The shutter was sluggish, so what better excuse is there to have a peek under the hood.

Here is a nice example of a Zeiss Ikonta 524/16 sometimes called "Mess-Ikonta", uncoupled rangefinder with a Novar 75/4 lens in a Prontor-S shutter, made between 1954 and 1956. We are going to do a full cleaning, and where possible, adjustments. Sounds like a daunting task? Not really...

Let us start by removing the top casting to have a look see.

First the Rangefinder focus knob. Being an uncoupled rangefinder, this knob actuates the rangefinder prism until the two images in the viewfinder line up and thus the actual distance is revealed by the number on top of the knob adjacent to the arrow marker. I'll let the images speak for themself... unless there is something important to remark on.

This is the advance knob assembly. It too is pretty simple.

Accessory shoe next.

Hmmm... What's this, different shims under the bottom right screw mounting position. We'll make note of that.

Last two screws and...

Lift it away!

Gather up any loose parts such as felt square light seal and front lens board release plunger.

Let's admire the simple beauty of this scene. Not much here but the bare essentials of a basic mechanism.

Here's how the Rangefinder works. When you turn the focus knob as indicated by Blue Arrow, the outer rim is a cam surface that pushes on the Focus Arm indicated by Red Arrow. The Focus Arm is hinged by a spring, Green Arrow,  which ensures it pushes against the Focus cam. The whole mess pivots and thus displaces the prism mirror as shown by Yellow Arrow.

The other side is the fixed semi-mirrored surface. Other than that there is the advance mechanism with its interlock to prevent double exposure. It too is pretty simple.

Lens and Shutter Assembly

I will be going through the dismantling and cleaning of the above Lens and Shutter assembly. It too is not that complicated either.

Start by removing this stop screw.

Unthread the front lens element and take note of exactly the point where the focus helical thread disengages. When we re-assemble the front lens element we will rethread it back on starting from this exact point. Hopefully if we are lucky the lens will be precisely back into the thread to be focused, corresponding to the distance scale.

Remove the front lens element and place it in a save place.

We'll remove all the lenses so that no harm will come to them while we further remove the shutter.

Remove lens element locking collar and...

Grab hold of the lens element...

Lift it away! Make note of which side of the lens faces out. On this one, there is a bevel around the perimeter on the front edge.

The front bezel is held on by a locking collar ring, shown by Red Arrow. The collar ring is locked by a screw that has a flat side, Yellow Arrow.

Turn the flatted lock screw so that the collar ring can unthread. I made a mark on the particular spot that engaged the lock screw so that at re-assembly time I may be able to have the same tightened specification.

Lift away the locking collar ring.

Remove front bezel.

The next item is the speed selector ring, which has a series of stepped cam positions that control the shutter speed actuator. There is a little rocker arm that will either fall out now or during the next step. Your choice on when to remove this part but have a look at how it rests before it falls out so that you do not have to guess at how it went.

Lift this away, making note of how it is aligned.

There you go, a naked shutter. Now to actually remove it from the camera for cleaning.

Working from the inside, use your spanner to remove the lens retaining ring.

Again, lift away and make note of any distinguishing features to tell which way the lens faces out. Mine had an unpainted band at the outside edge.

Now for the crappy part. You will need a really long spanner or have to custom make a removal tool to unthread the retaining ring. Another glitch in the plan is to unthread the retaining ring without screwing up the adjacent bellows surface and creating a pinhole or worse, highlighted by Yellow Arrows.

Necessity being the mother of all something or others, I decided to improvise and make a tool to unthread the ring. A visit to the plumbing section of my local hardware store found a piece of sink pipe. The diameter was pretty close, so I started to grind away until I came up with the following...

It ain't pretty but its got all of it's teeth. Two of them to be exact. And, they're bent in a bit to engage the retainer ring exactly.

Working carefully to not gouge or cut the bellows, unthread the offending retaining ring.

The whole shutter will now come away from the camera assembly. Nice!

Now what to do?

You could just dunk the whole unit into some solvent and hope for the best. But that would be too easy, much too easy!

Here at the Kiev Survival Site, we have a reputation of "going all the way". So with that in mind, start by removing the escapement mechanism. One screw is easy to locate.

The other screw is revealed by taking the cocking lever and move it.

When you move the cocking lever so that it arms, Red Arrow, part of the mechanism scoots out of the way, Blue Arrow, revealing the other screw, Yellow Arrow.

The whole escapement mechanism comes out as a unit. You may now clean this part separately and lovingly. If you are some sort of "keener", and who isn't, you may lubricate the shafts of the escapement mechanism with an approved light oil.

Just a work on said light oil. I use a synthetic arctic grade instrumentation oil made by Moebius, Arctic 9040. I have a friend who is diabetic and he is a great source for hypodermic needles when I need them for precise oil applicators. I leave it to you for alternate sources of hypo needles.

Disengage this spring from the post. This completes the front side for now.

Turn the unit over and undo these four screws. This will allow access to the blades in the leaf shutter. 

Here are those four screws. Make note of the the one longer one.

Carefully, and I mean, CAREFULLY lift the back off of the leaf shutter blades trying not to disturb the individual leaves like I did. Do as I say, not as I do...

Looks like I have to sort this mess out. Fortunately there are enough tell tale signs on each leaf to tell what is what.

Keeping track of which leaf came off first, very gently remove each leaf and set aside for cleaning. Lovingly clean each leaf with a soft brush in solvent.

To clean the leaf circular ring actuator, remove the five screws around the circumference.

To remove fully the leaf ring actuator for cleaning we need to do disengage this pin first.

Grab this here lever and...

Just move it to disengage from the pin.

Lift the leaf ring actuator from the rear. Now you can dunk the rest of the mechanism in solvent and spend a little extra time with a soft brush to clean all the surfaces that the leaf ring actuator slides against to ensure that the leaf shutter will operate to maximum expectations.

To assemble, just reverse the steps above.

If you have a method to test your shutter speed, have at it. For my Ikonta we find that at the posted 1/300 sec. actually runs at close to 1//200 or 4.65millisecond to be exact. I suppose this is pretty good considering the age of mechanism.

If all goes well and with a little luck, you'll get it all back together. Dress it up with a few accessories and you are set to go!

June 24, 2007