Tower 18b integrated exposure repair

[david_johnson64]

<p>I've got a Tower 18b (Mamiya Ruby variant, i think) with multiple problems. I'm trying to resurrect it as much for practice as anything else. Right now I have it disassembled about as far as I can without help while still having some hope of getting it back together, and I've either fixed or figured out how to fix several problems. Where I'm stuck is at the shutter assembly. This camera has a Copal-SVK shutter, with a coupled shutter speed/aperture control...or rather it should. If I understand operation right, the front ring should set exposure by matching needles on the top of the camera, then moving the next ring will change aperture and shutter together to maintain that exposure. <br>

The problems I'm having are that the exposure won't line up at reasonable values, I can feel gears slipping and the rings to control exposure seem to have too much in and out play. When I removed one of the lens elements a tiny screw fell out. I can't see any further disassembly that isn't disassembling the shutter itself, and that is likely to go beyond what I can fix. It's hard to believe that the shutter assembly can't be removed as a unit-Is there something I'm missing? Suggestions on where to go from here?<br /><br>

(pictures of the shutter and the loose screw)</p>

<p> <img src="http://i.imgur.com/Mic0FY9b.jpg" alt="" width="160" height="160" /> <img src="http://i.imgur.com/4BEWavkm.jpg" alt="" width="320" height="265" /></p>

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