Gluing Zorki 1/FED 1 shutter curtains: A few questions

[jim126]

Hello everyone. I have read many instructions on how to replace the shutter curtains, but a few things remain unclear. Firstly, where exactly do you place a mark on the rollers/drums before removing the curtains? Is it at the very edge of the curtain, at its first point of contact with the drum (fig. 1)? Or is it at the last part of the shutter that is glued (fig. 2)?
Next, which parts of the curtain/ribbons have the most critical positions? Fedka states "The position on the drum of the longer curtain is critical, as well as the long ribbons attached to the drum’s pulleys.", while Maizenberg says "The marks are made on the drum at the place where the long curtain edge was glued on. They are also made on the pulleys where the short curtain ribbons were. Do not make any other marks because the positions of the short and long curtain ribbons are not important." So which is it?
Finally, something more specific to my situation. The glue keeping the curtains and drum/rollers together started to come apart, and it is not really clear where the curtains were originally glued. Obviously, if the latter (fig. 2) method is the correct way to glue the curtains, I cannot glue the curtains using the previous curtain's position. So is there any way to glue the curtains through trial and error? I read that the accuracy has to be within 0,5mm, so how feasible would this be, and what would I be looking out for when testing the shutter? Thank you.

 

[JeffS7444]

I still consider myself a novice when it comes to replacing shutter curtains. But in at least one instance, I could not align per Fig. 1 because the edge of the original curtain had been cut irregularly.

Exactly where the ribbons are glued to the rollers isn't particularly important, but ensuring that they are pulling on the shutter lath evenly, and that the lath remains parallel to the edges of the film gate *is* important. Pretty sure that the factory employed simple assembly jigs into which the worker placed the drum and rollers, then glued the pre-assembled curtain/lath/ribbon into place. And they must have been able to do so reliably and quickly, and with a decent level of precision.

My first attempts at assembling lath/curtains/ribbons were dismal, ditto with attaching them to the drum and rollers: Everything was crooked, the curtain was being pulled at an angle, etc!

I have not fully mastered the art of ensuring that timing between curtains #1 and 2 is correct, but having a high-speed video app on my phone helps enormously in spotting problems before the camera is fully reassembled.

 

[GMOG]

The main thing you need to be concerned about is where the 2nd curtain is glued to the big drum, and also where the ribbons for the first curtain are glued to the pulleys on either end of the drum. The markings you need to make are where the ends of the curtain and ribbons are located on the drum and pulleys (sounds like you can't do that now). The attachment points on the spring rollers are not important apart from keeping things square.

If you loose the positions on the drum end all is not lost. I recommend that you obtain a copy of the following document written by Christopher Kuni:

Replacing Shutter Curtains on Screwmount Leicas

In that guide Mr. Kuni explains how you can determine where to attach the 2nd curtain and the 1st curtain ribbons by using thin double-sided tape to temporarily attach them for the purpose of trial fitting. After the positions are determined you mark them and then replace the tape with glue.

Speaking of glue, the best I've found is DAP's "Weldwood Contact Cement". I found it at a local Ace Hardware store but other places have it.

Dap 00107 3Oz Weldwood Contact Cement

Achieve professional-grade adhesion with Dap Weldwood Contact Cement. Fast-drying, high-strength, heat and water-resistant. Note: Hazmat fee applies.

www.contractorswholesalesupplies.com

 

[JeffS7444]

Actually, I should qualify what I said earlier: Some parts need precision, while others, not so much.

 

[Ko.Fe.]

shutter replacement1

The only Zorki repair site I was following to disassemble, replace and put it all together as working camera.