Replacing/Adjusting Pentacon FM Curtains

Picked up a nice looking Pentacon FM with a 50mm f2.8 tessar for a song and like almost all of these, the shutter curtains are shot. Full of pinholes, badly wrinkled which makes the shutter act erratic. I can tell all the speeds etc seem to work when the wrinkled curtains don't hang so I looked into getting them replaced. The only estimate I got was going to be almost $350 and then Rick Olsen (the focus screen guy) sent me some DIY instructions and mailed me some curtain material so I'm going to try to replace them myself. I'm about 1/2 way done and I'm feeling confident I can do this. So far it seems fairly simple to work on.

My only concern is setting the spring tension and getting the shutter speeds at least close. I plan to only use B&W film in it, which has a lot of latitude and likely will mostly be using the lower speeds, but I do wanna make sure it doesn't fade etc. I will probably reach out to Rick again once I get it back together for tips on final testing but any tips or links to info would be great.

Stephe

Hello Stephe, did you manage to successfully get this camera working in the end?

StepheKoontz said:

My only concern is setting the spring tension and getting the shutter speeds at least close.

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ic-racer said:

Build a shutter tester for Focal Plane shutters - Cheap, Easy & it Works

Hello Everybody, #1 There are many home-brew shutter testers out there, some use audio to try to detect the speed, others use an Arduino and one sensor (so will not work correctly) and there are better ones that use two sensors. A problem seems to be a misunderstanding of how a focal plane...

www.photrio.com

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glad to see my design recommended )

I know nothing of the pentacon, but on the Zenit, the positioning of the first curtain ribbons and second curtain, on the drum is critical. Everything indexes from there.

If incorrect, the curtain gap will be incorrect, the curtains may not overlap, or overlap too much on the return, or second curtain will not release at the correct position of the first curtain.

My solution was to make a jig, which holds the inner & outer of the drum t the correct (un-cocked) position with distance markings & clamps, to hold the curtain lathes. the ribbons/curtain can now be re-glued onto the drum. I use rubber solution glue. The tpye to repair bicycle punctures.

The measurements and alignment for the jig were found by using a shutter mech from a camera that had good curtains that had not become detached from the drum.