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The Ikonta Korner
Super Ikonta

Now firmly hooked on medium format folders, it only seems natural that a Super Ikonta should be added to the arsenal.

 

Here is a nice example of a Zeiss Super Ikonta IV, 534/16, coupled rangefinder with a Tessar 75/3.5 lens in a Synchro Compur MX shutter, made between 1956 and 1960. We are going to do a full cleaning, and where possible, adjustments. This shutter is the later version with the one main spring. A bit of a challenge but once you get the hang of things it is not that difficult.

 

You have two choices to go by, lift the top and clean there first or you can go for broke and have at the shutter. OK, let us take the easy route first. Off comes the top casting... The pictures say it all.

Other side...

Let's have a gander at this cam actuator do-jigger for the light meter matching needle before we take it out.

 

Remove screws for top casting

 

Some of you may get stuck on this next step. I did... For the life of me I couldn't get this eye piece bezel out.

 

OK, I got the outer bezel removed by unthreading. That was easy but the inner eye piece bezel would not budge.

 

Time to use some excessive force. Grab what ever rubber device you have handy and give this bugger a real good leaning on while twisting. Fancy language always helps too!

 

Unthread to remove.

 

Remove this access plug too as it will hang up when trying to remove the top casting.

 

OK, lift away me boy-o's!

 

Here's what you will find under there.

 

Going further into it we'll need to get access to the viewfinder lens assembly to clean. From all accounts of the evidence of glue around the clear light meter window this camera was obviously dropped on it's head as a baby. Therefore my disassembly at this part may be slightly different from the standard.

Remove these four screws.

 

Then this big guy here.

 

The light meter window and adjoining exposure dial shaft base. It should come out as a single unit but things being as they are mine is in separate parts.

 

Pull the front door latch plunger.

 

Remove the light baffle taking care not to mangle the light meter needle.

 

Now we have access to clean the rangefinder glass. Remember that it may best no to clean the semi-reflective prism surface as damage could result from any wiping action.

 

Lens and Shutter Assembly

To remove the shutter assembly one must gain access through the back where we find a retaining ring that has two notches that are engaged with a not too fancy a tool of my own making.

 

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 just right to engage the retainer ring exactly.

 

Being careful with regards to above note about the adjacent bellows, unscrew the retaining ring.

 

Remove the shutter mechanism as a whole unit.

 

Don't forget to account for the shims between the shutter and body.

 

Here's what you've got. The shutter as seen from the back side. Ready to dismantle.

 

Lift off the focus wheel.

 

Next the shouldered ring.

 

Lift off spacer washer.

 

Let's get the lens out and away from harms way. Should have done this first thing.

 

For a reference point, set the lens at infinity for the next step and make note of where it aligns to.

 

Loosen the three set screws around the focus collar.

 

Lift off the focus collar away from the front lens element.

 

Unscrew the lens element helical. Make note of where the front lens disengages from the helical as this will be your insertion point to re-engage the lens with the helical.

 

Down to the last lens. This one unscrews as well but it might a tough one to get a grip on.

 

Using a rubber stopper to aid in getting a good grip, lean into this one to start unthreading.

 

Unscrew and lift away.

 

Ready to go inside? Remove this lock screw from the retainer ring.

 

Unthread this retaining ring.

 

Lift off the exposure selector collar.

 

Lift off the shutter speed selector.

 

Just take a moment to examine the speed selector cam.

 

When you lift off the speed selector cam you get to see how business is conducted.

 

Steady your nerves, we are now going inside the guts of the beast. Pull the end of the return spring from the post as indicated by Yellow Arrow. Before proceeding further, make note of how the shutter cocking lever teeth engage the main spring gear as indicated by Blue Arrow.

 

You are free to remove the shutter cocking lever.

 

Remove the main drive gear

 

Remove the double exposure prevention latch.

 

Time to get some of the internal organs out. Remove this screw and...

 

Take out the exposure delay mechanism. This is the rundown escapement to enable the time delayed shutter release.

 

Time to move on to the main shutter escapement. Remove this screw.

 

There is one other screw to remove as indicated by the Red Arrow but first make note of the two other items. The two arms indicated by Blue and Yellow Arrows must rest behind or against the indicated surfaces. When it comes time to replace the escapement assembly these two arms will need to be deflected as they are spring loaded to rest against these surfaces.

 

Now you can remove this screw.

 

And, 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 frankly who isn't, you may lubricate the shafts of the escapement mechanism with an approved light oil.

 

Just a word on said light oil. I use a synthetic arctic grade instrumentation oil made by Moebius, Arctic 9040. If you know of any friends who are diabetic they can be a  great source for hypodermic needles when the need for precise oil applicators arise. I leave it to you for alternate sources of hypo needles.

 

Unlatch the end of the main drive spring, it just tucked into a recessed slot.

 

You can now remove the main drive spring and drive actuator.

 

The shutter actuator lever may be removed but first to highlight the return spring, as indicated by Yellow Arrow. It just tucks up adjacent to the shutter body as shown by Blue Arrow.

 

The shutter actuator lever just lifts out.

 

Flip it over and remove the three screws that hold the aperture lever on.

 

The aperture lever just lifts away.

 

Next remove this spacer do-jigger.

 

The selector ring for Delay-X-M comes off next. The following step involves the three screws highlighted which holds the two halves of the shutter together. If the individual leafs of the shutter are clean and you do not suspect any need to clean these then you may disregard dismantling any further. For those willing to brave it out and do a thorough dismantle, read on.

 

After removing the previously mentioned three screws, carefully, and I mean CAREFULLY, lift away the half of the shutter from the leaf blade carrier assembly so as not to disrupt the individual blades. You will need to re-assemble the individual blades in precisely the same order and position.

 

Here we find some evidence of oil on the blades, so it is a good thing we going the full distance with a cleaning. Notice which leaf blade is the top-most amongst the stack. For what ever reason, I'm showing the removal of the blades from the aperture half of the shutter. It makes much more sense to remove the blades from the view as shown above as this will be how the procedure is presented later.

 

Carefully remove each blade in succession for cleaning, keeping track of the order in which they came off.

 

Using what ever method at your disposal, clean the control half of the shutter assembly. Which method or substance you use, just make sure no residue is left behind.

 

Once you've got both assemblies nice and clean, it's all down hill from here.

 

OK, the trick to getting all the leaf blades back in place is to use something to support them in the center of the shutter opening otherwise they have a tendency to fall making for a frustrating event.

 

Using any round item you have, be it a cut down broom stick, old wine bottle cork, rubber stopper, or as I have a round cylinder of steel, place it under the shutter assembly to create a flat surface through the opening of the shutter.

 

Start placing the leaf blades back in order on the locator pins.

 

When placing the top aperture half of the shutter back on to the other half, be VERY careful not to disturb the gently sitting leaf blades. This will likely try your patience and you will need to have a couple attempts at it.

 

When putting the selector ring for Delay-X-M back onto the shutter assembly, a small bead of non-creeping grease ensures a smooth operation. Any sliding or rubbing surface not involved in shutter timing or actuation should be treated likewise with some grease. The following series will illustrate a few items that require some attention with grease.

 

 

To make a long story short, re-assemble in the order items where removed. For reference, here is a close-up showing the flash delay with all the springs in place. With some exceptional luck, it will all come back together and work.

 

Adjust the position of the escapement mechanism to affect shutter speed fine tuning. Snug up the screw at the Blue Arrow. Go out to the garage and grab your old set of feeler gauges, which probably hadn't been used since back in the day when one could and did work on one's own car. With your feeler gauge, you can control the offset indicated by Yellow Arrow and thus the shutter adjustment.

 

Using a photo-transistor detector we can measure our shutter speed with simply a flashlight as a source.

 

Just a word regarding effective shutter speed. All leaf type shutters exhibit a time lag, or latency, while opening and closing that is different depending upon the aperture opening. As the shutter begins to open a small amount of light is entering and hitting the film. This is expressed by time duration 'x' on the waveform. Assume the aperture is set to the largest setting, the shutter continues to open allowing in a greater amount of light. When the shutter has fully opened there is a consistent amount of light hitting the film. The shutter stays opened for a predetermined amount of time as set by the shutter speed, then starts to close. This is expressed by time duration 'y' which is somewhat different from time duration 'x'. Since the shutter cannot instantly open and close, there will always be a latency while the shutter actuates. This would be the difference between time 'x' and 'y' divided by 2. Or, in simple terms the time required for the transition from the top of the waveform, at the left most point of 'x', and the bottom at the left most point of 'y', for the opening latency. The closing latency is the waveform transition on the rising portion at the right.

So how does one actually measure a leaf type shutter which when depending on the aperture selected you may have a different time duration? Consider that most of the time we use an aperture of f8 or f11, one could set the measurement point, or if using a photo detector the sensitivity trigger, at the desired f8 opening point which would be somewhere halfway up the slope as expressed by time duration 'n' in the diagram above.

 

As recorded by the photo detector we can see that the duration of the time that the shutter is in the state of either opening or shutting is a significant portion of the total elapsed event. It is most profound at the very fastest of shutter speeds and less of a concern at slower speeds. Here we see a measured opening duration of 328 micro-Seconds for the waveform transition on the falling edge. The settings are at f11 for a total time of 2.33 milli-seconds corresponding to the 'n' time duration, which for the fastest setting of 1/500 is pretty damn good.

 

If all goes well and with a little lot of luck, you'll get it all back together. Add some accessories and hit the streets in style.

 

October 20, 2007