albada
Subscriber
The film advance devices in the various Retinas are actually quite robust, and I rarely find one that's truly "broken". (I service an average of three of them a week) The vast majority just need old lubricants cleaned out and replaced. The IIc/IIIc types (late 1950s) has a problem with the nickel plated brass toothed rack that links the film advance to the cocking of the shutter: if the camera has not been serviced in decades, the lubricants dry out and a lot of extra force is applied to the rack, which inevitably results in distortion/breakage of the teeth. In 1959 it wasn't considered a "flaw", since replacement racks were readily available, but 60 years later, its a different matter. Which models do you have, and can you describe their problems?
The Retina IIa and Ia have a particular issue where the tiny spring that controls the frame counter eventually wears out from metal fatigue, and so the tip breaks off and the frame counter stops working. But that doesn't affect the functioning of the film advance.
Paul, I have devised a few ways of (1) repairing/restoring racks that are damaged or stripped, and (2) preventing racks from being damaged. I've documented these methods on my web-page:
Restoring racks: https://fixfilmcamera.com/FixRetinaRack/FixRetinaRack.html
Preventing damage: https://fixfilmcamera.com/BraceRetinaRack/BraceRack.html
Preventing damage: https://fixfilmcamera.com/BraceRetinaRack/BraceRack.html
You might find some of these ideas helpful.
Mark Overton