Film..."filling up" on take up side, jamming up advance

[kaiyen]

Hi all,
I have intermittently had problems where the advance lever/advance sprockets in my canonet would "jump" or slip. The film was clearly not advancing fully when this happened. I thought it was because moisture had gotten into the camera, as this happened for the first time during my 24 hour shoot in San Francisco, when it rained quite a bit.

However, it happened again yesterday, in my nice and dry canonet. I looked closely, and I think what is happening is that on the take up side, the film is rolling up and getting too thick. The advance lever then can't move the film farther because it's too "full" on that end. This is after just, say, 10 frames, btw - not at the end of a too-long bulk roll.

I don't want to mess with the quickload plate, which is what seems to be putting pressure down on it. It's also quite possible that this is happening because of the foam seals I put in - maybe they are too thick, and putting more pressure down than should. But I thought I'd ask first.

any ideas?
allan

 

[FrankS]

I had something like this happen once when I did not properly insert the beginning of the film to the take up spool (in A Rollei 35B). The advance worked for a few frames but then became stiff as the film just bunched up in the film take up side of the camera instead of being rolled onto the take up spool.

Could it be that the quick load system is not loading the film onto the take up spool corrrectly?

 

[jlw]

Try loading the camera with a scrap roll, advancing the film until you encounter the problem, and then open the back and check your hypothesis. If the film isn't rolling up tightly on the take-up spool, it could certainly cause the type of symptom you're getting.

The take-up spool has a slip clutch on it -- necessary because as more and more film builds up on the spool, it has to be turned fewer degrees per frame. (The actual film length, of course, is metered by the sprocket shaft, which always pulls one frame's worth of film out of the cassette.)

If your slip clutch is too loose, the film won't wind up tightly, and will fill up the takeup compartment before you get to the end of the roll.

 

[payasam]

The QL mechanism has small rubber pads which harden with age.

 

[kaiyen]

Payasam - where are these rubber pads? The mechanism seems all metal to me.

What seems to be happening is that the springs in the take-up end that should, presumably, close up and make the spool smaller are not in fact doing that. So the spool stays at "maximum" size and therefore so does the film roll as it is being taken up. Which means it fills up, and can't advance. Does that make sense?

jlw - how would I figure out if the clutch is slipping?

thanks,
allan

 

[Doug]

...If your slip clutch is too loose, the film won't wind up tightly, and will fill up the takeup compartment before you get to the end of the roll.

Sounds right to me; I have this loose slip-clutch condition in a Pentax ME-Super... It will run 24-exp rolls just fine, but the takeup chamber will jam full before the end of a 36-exp roll.

 

[payasam]

Sorry about the lousy picture, Allan. Look for the little black fellow in the middle. It is rivetted to a spring-loaded tab on the take-up spool.

[edit] Managed a slightly better picture. The little fellow in the centre of the frame.

 

[kaiyen]

Payasam - got it, now I know about what you are talking about. Does the hardening of that rubber mean less grippiness and therefore the film slips a bit?

allan

 

[payasam]

Allan, I cannot figure out just what problems might be caused by the hardening of the rubber pads. It might be a good idea to ask on a Canon forum somewhere. Photo.Net or

http://groups.yahoo.com/group/CanonFD/
http://forums.canonphotogroup.com/

This may not be of any use, but I had a winding problem with my FTbN (also QL) a couple of years back. Somewhere around the 25 exposure mark, it would become impossible to advance film. Attempts would only tear the sprocket holes. The tech who looks after my SLRs fixed it by putting a little thin oil -- just two drops, with a needle -- on the rewind shaft.