Leica LTM IIIc curtain ribbon getting caught in gears

[olliewtf]

Hey gang!

New here, but needed some advice re a cheap iiic i picked up. After thinking Id shot a whole roll of award-winning photos, I realised the opposite. Film hadnt advanced at all! anyway thats not my main issue - whilst i was faffing with the camera to rewind the film something jammed.

I took it apart (which I had already done previously to clean the slow speed escarpment) and saw that the curtain ribbon fixed to the large drum, at the bottom of the drum, had somehow slipped off the drum and caught itself in the lower gears. It was still glued to the drum.

After lots of swearing I managed to re-locate it back on the drum, and all fired correctly. But, after a few shots, I can see the ribbon wants to move southward again - so im not happy that it wont do it again.

What are my options here? I'm trying to avoid doing anything invasive enough to require resetting the curtains, as im not confident Ill get this right. Would be good to know whats causing it? Its as if the ribbon enters the cage too low if that makes sense. Ive thought of maybe ungluing and re-gluing the ribbon a little tighter but im worried this would affect curtain timings.

Im trying to do as much of this myself, not only because im generally just like that, but also because this camera was rather cheap and it would be great to keep it that way!

Kind regards

 

[Phil_F_NM]

Send it to Youxin, it will come back in excellent condition and it will still be cheap.

Phil Forrest

 

[xayraa33]

"Ive thought of maybe ungluing and re-gluing the ribbon a little tighter but im worried this would affect curtain timings."

The curtain(s) running time can be easily adjusted by tensioning or un-tensioning the spring loaded shutter curtain spools via the two gear and worm at the base of the shutter crate on the IIIc, ( and it is a hell of alot easier to do than on a Leica III)

And this is something you would do anyways, as you always have to verify the correct running time for the opening curtain and for the closing curtain,( and they don't all run at the same speed velocity like one would first imagine) .. not only when cleaning and oiling the gears and bearings that run the shutter curtain system, let alone when the length or tautness of a curtain ribbon has been altered by re-gluing.

You will need a shutter speed tester for accuracy or do it the old fashion way to get in the ballpark, with a CRT TV screen and watching for a uniform parallel slit width, but this method might be more trouble than its worth for curtain running times of 1/30 or less and if you lack the experience of interpretation .

http://rick_oleson.tripod.com/index-135.html

 

[olliewtf]

I really want to fix this myself. Always done that with everything I own. It may come to that but im sure someone has an answer!


in reply to xayraa33 - thanks for that. Im not confident yet that unglueing and re glueing the ribbon is the answer. I cant imagine why it would be slowly working its way off the drum and into the gears.

I need to learn more about setting the curtains i think, then I may have more confidence in maybe taking the crate apart to investigate further.

SOmeone had posted up a baseline setting for the adjusters, im wondering how useful this is and if itll get me close enough until i find an old tele! - or i turn out the adjusters (do they bottom out?) and record the turns, take it apart to see whta the problem might be, then put it back together with the same turns?

 

[xayraa33]

(I cant imagine why it would be slowly working its way off the drum and into the gears.)

The ribbon could be stretched and frayed and/or the alignment could be off, especially if someone else did a kitchen table bodge job on that old camera.

I had one camera with a similar problem once, and it turned out one ribbon was replaced with a ribbon of the wrong thickness and the camera never ran right and the owner gave up on it.

 

[olliewtf]

okay that's a good point.

i think i may need to remove the shutter assembly for inspection then. does the tension need to be relieved to do this? if so, i could back off the adjusters and record the turns to save me from at this stage having to time the thing properly?

tbh the curtains look original, theyre that strange wax cloth material. there is some cracking but they hold light. might be worth just replacing them though...

what would you do? take more apart? I cant see any resolution here without inspecting the curtain mechanisms, which is going to mean resetting the curtains. so think i may have answered that one me self!

 

[Phil_F_NM]

If the rubber coating on the silk curtain is cracked, the curtains need to be replaced. It won't be light tight and the rubber can flake off, making all your work worth nothing.

Phil Forrest

 

[xayraa33]

okay that's a good point.

i think i may need to remove the shutter assembly for inspection then. does the tension need to be relieved to do this? if so, i could back off the adjusters and record the turns to save me from at this stage having to time the thing properly?

tbh the curtains look original, theyre that strange wax cloth material. there is some cracking but they hold light. might be worth just replacing them though...

what would you do? take more apart? I cant see any resolution here without inspecting the curtain mechanisms, which is going to mean resetting the curtains. so think i may have answered that one me self!

You only need to release the tension if the crate is going to be dis-assembled to individual pieces. Replacing the shutter curtains and ribbons in total will require slacking the tension but that will be a moot point once you unglue the ribbons and one curtain from the main drum.

It is not an easy job for a first timer, I suggest you first practice on a few parts Fed or Zorki cameras first if you want to learn the ins and outs of that mechanism.

Remember, the Leica Barnack shutter mechanism (and their copies) looks deceptively simple but there is a lot going on there that is not first apparent at a cursory glance, and one wrong move leads to hours of frustration.

Paying 80 to 200 dollars to get it properly repaired by a knowledgeable camera tech with solid repair experience will seem like peanuts and a good deal in retrospect.
Cameras as fine as a Leica deserve that IMO.

 

[olliewtf]

all noted. I think this problem is probably best solved with a curtain replacement all things considered. More research needed for sure - I may just put it back together and hope i can shoot for a bit without the ribbon coming off again as I start gathering the courage and knowledge to have a go, or decide to let someone else sort it.

the camera has only cost me £100 so far, with a nice summar lens. would be great to get a roll out of it yet!

if anyone has any good links or tips on any shutter work im all ears!

 

[Peter Jennings]

If you really want to do this yourself, you can. Curtain replacement is a tedious and frustrating job, but it’s not rocket science. I’ve done it 3 times so far (all on non-Leicas), and it wasn’t until the third time that I started to get comfortable with it.

Aki Asahi sells curtain material and ribbon.

 

[Phil_F_NM]

Earlier today I was looking for this photo of the curtain of my IIIf that had curtains that were cracked but appeared to be light tight with a flashlight. This is how light tight the first curtain was with some 400ISO film inside.
It's one of my favorite images now.

Phil Forrest