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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
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