Rolleiflex SL35 (German Made) Repair...What Could Be Wrong??

[ic-racer]

I recently found another German Made Rolleiflex SL35. This is an early one, because it only has a single slotted screw on the front top cover. The later cameras had cross-point screws, and had a second screw on the rewind-side of the top.

Without much examination, one can see the camera's mirror is stuck up. What else is wrong...?

 

[ic-racer]

After opening it, it was clear this one has been opened in the past. There were greasy finger prints on the pentaprism, the focus screen and mirror.
One of the screw heads holding the mirror box to the bottom was sheared off. Among other things. Whoever opened it last, was unable to fix it.

 

[ic-racer]

What is wrong? The shutter releases the mirror, which goes up ok. The first curtain is released but the first curtain won't go all the way across the film gate. It gets held up and won't complete the cycle. Leaving the mirror up.
The mirror is also wobbly.

There is a brake on the first curtain take-up rod. It is at the bottom and it consists of a cam on the spinning rod which touches a spring-loaded lever. The lever is frozen and the take-up rod of the first curtain, can't spin all the way to fully un-spool the first curtain. It stops dead.

After cleaning and adjusting the brake, the first curtain would travel all the way across.

But the shutter was still buggered...

 

[ic-racer]

It seems the adjustment screw for the first curtain take-up drum spring was frozen to the drum. So, twisting the screw to change the tension merely twisted the drum.
this had the effect on the prior repair attempt. By twisting the screw the drum rotated, releasing any tension on the ribbons and the top ribbon got bunched up. After the frozen screw was loosened (with alcohol), and tension applied to the take-up drum, the ribbon became tight again, but it was twisted in two places. This prevented the second curtain from coming over.

This was a little of a challenge to fix without taking the curtains out. The upper ribbon passes tightly around rod #223 in the picture. As it passes around that rod, it is twisted and stays twisted.

Eventually I got the un-twisted portion to pass around the rod #223 and that fixed it.

 

[ic-racer]

At this point the shutter fired completely, but the mirror was still wobbly. It turns out the spring #33 in the diagram was not affixed on the tab of part #34. The spring was hanging loosly. This spring keeps tension on the mirror via the pin on the side of the mirror.
Re-affixing the spring, cured the wobbly mirror issue. The rotating portions were oiled and the levers that clash into each other were greased. After this the mirror box functioned perfectly.

There is a trick to getting the mirror box in and out. This is outlined in the "SL35 Service Article" that can be found on the "Learn Camera Repair" website.

The mirror was a dirty mess, so it was careuflly cleaned at this time (microfiber cloth and alcohol).

 

[ic-racer]

The pentaprism fits into a plastic frame. Looks like both sides of the frame broke where the brackets that keep the pentaprism in place attach. Some acetone-based glue was used to re-glue the broken plastic. In case the repair does not hold (though usually the melting-type of glue welds the plastic nicely) a rubber bumper was placed at the top of the pentaprism cover to help keep the pentaprism in place.

 

[ic-racer]

Now time to test the shutter and exposure meter.

First the slow speeds. The 1/4 and 1/30 speeds did not engate the escapement and were too fast. This was because someone previously rotated the eccentric too far (label "1/4" in the diagram). The notch is supposed to point strainght back. Rotating the eccentric back in its original position cured the 1/4 and 1/30th problems.

 

[ic-racer]

Now the fast speeds.

The manual calls for curtain travel times of 10.9 to 11.4 milliseconds as measured with Rollei's EKZM shutter tester. The manual does not state the distance across which this is measured.
I was able to find a picture of the EKZM tester and figured the distance between the sensors is about 35mm.

 

[ic-racer]

With all the spinning portions of the shutter mechanism cleaned and lubricated, the 1/1000 setting was still too slow. This means the slit in the shutter is too wide at 1/1000. This is because the second curtain is being released too late.

Close examiniaton of the second curtain release lever revealed it was slightly bent. How??
Anyway the bend caused its lever-action to be shorter, thus release too late.

After bending it back, the fast speeds could then be set within the adjustment range available by the screw seen in post #7 above.

 

[ic-racer]

As was the case on some other SL35 cameras I repaired, the window on the ASA dial was foggy. This was fixed with some plastic polish.

There was a screw missing on the shutter speed plate. I found one in my spare parts collection. Not the same type of head, but the threads were the same.

The arrows point to the glued repair of the pentaprism support. Seems to be holding OK.

 

[ic-racer]

The exposure meter tested within 1/3 EV on the range from EV5 to EV16 using a zinc battery. No adjustements needed!!

The X-contacts got bent when removing the mirror box, so the flash would not fire. Using my shutter tester I re-bent the contacts so they close about 1 millisecond after the first curtain is fully open.

Here it is after cleaning and re-assembly:

 

[ic-racer]

Considering this camera was totally non-functional. I'm very happy with the results below. Gray area is ISO 516 tolerance at 0 to 40 centigrade.

 

[Nicholas Lindan]

Impressive bit of work.

It seems most of the work you did was the undoing the "repairs" perpetrated by the previous owner (or owner's relative). I wonder what the original problem was.

The litany of the camera's bungled repairs reminds me of the nursery rhyme about the old woman who swallowed a fly, then swallowed a spider to eat the fly, then swallowed a bird to catch the spider ... then swallowed a horse to ... don't know why, perhaps she'll die.

There is an Engineering adage: "Fix anything long enough and you will really break it."