Zorki 4 after CLA: everything working except for B

[fub]

Hello everybody,
this is my first post on this forum 🙂

i have recently acquiered a Zorki 4 (1964 Model) that had problems with a slow second curtain at slow speeds. So i did the deed and gave it a CLA. It was the first time i have been doing such in depth CLA on any camera.
I think it went pretty well. Right now i have the slow speed machanism installed and all the slow speeds work fine. The only problem i still have is that B is not engaging at all. I have taken that delay mechanism out so many times last night that my fingertips are still hurting and the skin is still peeling off. i adjusted the little notch in relation to the little gear that drives the lever that blocks the 2nd curtain in all possible combinations, i tried different notch positions with the machnism installed and tensioned (losening the little ring on top, moving the big gear around) and i have read all the manuals and seen all the videos at least twice.
everything seems to be how it should be it is just that that little lever that should stop the 2nd curtain from closing is being held open by the little gear under the delay mechanism when in B mode.

i am actually very close to giving up on this nonsense. you guys are my last resort.

with the picture i try to show you the situation of the lever for the 2nd curtain when in b mode. one with shutter wound and one with shutter released.

does anybody have any ideas why this annoying situation is the way it is?

did i mention that it is really frustrating and annoying? 🙂

cheers

 

[fub]

shutter released

 

[Valkir1987]

did i mention that it is really frustrating and annoying?


everything seems to be how it should be it is just that that little lever that should stop the 2nd curtain from closing is being held open by the little gear under the delay mechanism when in B mode.

This is the moment in the progress when you need to take a break. If you made it this far, patience will do the trick. This is your first serious CLA. After years of repairing, curiousity replaced my frustration. (mostly)

The notch that holds the second curtain for the slow speeds, should open and close when you manually wind the gear for the slow speeds. In rest, the notch should stay open. The spring on the slow speed mechanism needs enough tension.

When set to 1/125, the speed selector knob should almost touch the brass knob of the big gear wheel of the speed selector.

 

[JeffS7444]

I encountered something similar with a Nikon F, and again with a Samoca, and I think it took me a few days to solve: I needed to bend a soft metal part slightly. Perhaps I had straightened it out previously, thinking it was misshapen. I realized that in 1950s Japanese cameras, and Compur leaf shutters, that's how some critical adjustments were made, so be careful about what you attempt to "correct"!

 

[fub]

I needed to bend a soft metal part slightly.

found the reason! that little spring that goes on the bracket for the second curtain (the one with the long spindle going to the bottom of the camera) seems to not have enough tension. when i hold down the bracket with my finger the 2nd curtain stays open and releases when releasing the bracket. i did that a bit and eventually B startet working, but now it is not working again 😀
any tips on how to improve the downward force of that little spring that pushes the bracket down? should i increase or decrease the bend angle of that spring?

exciting! almost there 🙂
attached a picture of bracket, spring and how far they are being pushed down

 

[JeffS7444]

found the reason! that little spring that goes on the bracket for the second curtain (the one with the long spindle going to the bottom of the camera) seems to not have enough tension. when i hold down the bracket with my finger the 2nd curtain stays open and releases when releasing the bracket. i did that a bit and eventually B startet working, but now it is not working again 😀
any tips on how to improve the downward force of that little spring that pushes the bracket down? should i increase or decrease the bend angle of that spring?

exciting! almost there 🙂
attached a picture of bracket, spring and how far they are being pushed down

I try to avoid bending springs, because when all else is working correctly, even aged springs usually provide all the force that's needed. See if there's something else that you've overlooked.

 

[fub]

I try to avoid bending springs, because when all else is working correctly, even aged springs usually provide all the force that's needed. See if there's something else that you've overlooked.

after i opened the first curtain via pressing down on the breaket directly i can reach over to the normal shutter release button and hold that button down instead of the breaket. when i slightly move the button the breaket moves with it. when the shutter is not wound, the breaket does not move when i press the shutter release button, even though the spring plate at the bottom does.
could it be something about the spring plate at the bottom? maybe wrong tension?

edit: got it done! i relubrricated the shaft but that really did not help much. ultimatly i bend the torsion spring a bit to increase downforce. it works! i probably have bend the spring a bit too much during reinstallation of the shutter. had to take out the part many times. anyways it works now! i'll stop for today and reassemble the rest tomorrow

 

[fub]

was about to finish this camera but one of the two screws that sits in the slow speed mechanism just stripped. what can i do? the mechanism does not work since it keeps moving up on one side which causes it to slip.
also that bloody screw just fell down and went into hiding somewhere on the floor.

is my only option to redrill these holes? any other way of handling that? i do not have the tools for it and the camera will eternaly be bricked if that is my only option. any way to get this thing running on the faster speeds without this godless mechanism?
if drilling is my only option: which tools do i need? what sizes are the screws? how to call the odd screwhead so that i get the right screws?


i was so close :/

 

[Valkir1987]

I’m not at my workshop at the moment to check. It could be M2 or M1,7 with a cilindrical slotted head. The screws are made out of iron (or a soft kind of steel) and the foot that holds them from cast aluminium. You can drill and tap the hole to a larger size. Or repair the hole with metal of epoxy, and drill and tap to the original size. I may have a spare foot somewhere, but I won’t be back at my workshop untill january.

 

[fub]

I may have a spare foot somewhere, but I won’t be back at my workshop untill january

i can put it away for some time and start working on my Zorki C instead. Would be great to have a spare foot, as i would otherwise need to buy tools and all that. On the other hand these tools could prove usefull in the future.
Thinking about it i would certainly drill out the hole a bit and use a bigger screw. Could not find my caliper to check the sizes. especially the little hole in the slow speed mech that the screw would have to fit through.

i have a suspicion that the screw that goes through the gears was already stripped from the factory. at least overtightened. it was very loose when i took it out, probably barely hanging onto what thread was left.

please let me know once you are at the workshop if you have a spar foot! i'd certainly prefer that to redrilling

 

[fub]

I’m not at my workshop at the moment to check. It could be M2 or M1,7 with a cilindrical slotted head. The screws are made out of iron (or a soft kind of steel) and the foot that holds them from cast aluminium. You can drill and tap the hole to a larger size. Or repair the hole with metal of epoxy, and drill and tap to the original size. I may have a spare foot somewhere, but I won’t be back at my workshop untill january.

do you know if a foot from a Fed-4 or Fed-5 would fit? might be able to cheaply get a neglected one without lens for cheap

 

[Valkir1987]

do you know if a foot from a Fed-4 or Fed-5 would fit? might be able to cheaply get a neglected one without lens for cheap

I've looked in my workshop, but could not find the part sadly or a donor body. The foot from a Fed-4 or Fed-5 would not fit, they have a different shape.

 

[fub]

I've looked in my workshop, but could not find the part sadly or a donor body. The foot from a Fed-4 or Fed-5 would not fit, they have a different shape.

thanks for looking anyways! i'll have to get some small drills instead than.
meanwhile i also took out that spring from the film advance mechanism to use for a Zorki 1 that had that spring twisted. Can i take that spring from a Fed-4 or 5?