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Loosing loop on Krasnogorsk 3


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#1 Peter Gilabert

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Posted 22 January 2017 - 07:31 PM

I know it's just a K-3, but-

I've tried everything, taken this little sucker apart and put back together dozens of times, watched all those k-3 threading videos and for the love of God CANNOT FIGURE OUT what is going on to cause the upper loop to disappear and jam.
I've raised and lowered the main sprocket, (loop formers are removed), it just won't hold the film in the perfs on the upper loop. ( I can tell by the damage, it goes through ok for a second or two).
It couldn't be that silly v shaped plastic thing you snap on the T shape lock is it? Cause I think I tossed that. So frustrating that everything else seems to work... Help!
Ideas?
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#2 Wiliam Cardoza

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Posted 22 January 2017 - 08:14 PM

Have you ever used this particular camera successfully? Or a K-3 at all?

 

T-shaped lock?  Do you mean the film pressure plate?  That would  be the thing that slots in right behind the film where it's exposed.  That would probably mess up your loops...actually i just went to test that theory and the loops held.

 

Are you closing the bottom sprocket spring?  I don't know what there called exactly but it makes way for the film to be threaded and then you snap it back so it holds the film snug etc.  

 

Err i used to have problems not having the loops exactly the right proportion 1:2 top loop being slightly smaller.  But i just tested that theory too and after taking out the pressure plate, the top sloop grew a proportion to be even with the bottom loop and it still held....

 

LOL


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#3 Peter Gilabert

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Posted 22 January 2017 - 08:46 PM

William,
Yes and yes.
I'm hip to the pressure plate, that's in. All those rollers that swing out are locked in. It used to be fine. I was talking about that silly v shaped thing that fits on over the T shape door lock, but I don't think that's it.
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#4 Dom Jaeger

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Posted 22 January 2017 - 10:06 PM

So the pull down is advancing the film, but the sprocket isn't feeding the loop through?

There can only be a few reasons that the sprocket isn't engaging and pulling the film through. Either the sprocket is slipping (can you stop it turning by hand while the camera runs?), or the guides are not holding the film tightly enough against the sprocket (do they lock in, is the spacing correct?).

If the perfs are being ripped, the film is somehow being held on the take-up side (is the door clamping on the spool, does the spool spin freely?)
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#5 Peter Gilabert

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Posted 22 January 2017 - 10:39 PM

So the pull down is advancing the film, but the sprocket isn't feeding the loop through?
II feeds it through fine, but the upper loop just dies after a second or two, then everything gets sucked in towards the pressure plate.


There can only be a few reasons that the sprocket isn't engaging and pulling the film through. Either the sprocket is slipping (can you stop it turning by hand while the camera runs?), or the guides are not holding the film tightly enough against the sprocket (do they lock in, is the spacing correct?). I know the sprocket is tight, it can't be turned like you said. I completely understand how the flat part is held tight by that left screw, all good. Somehow I guess even though it's locked in, for some reason the film just isn't being held tight enough against the sprocket on that side. Before I run it, I pull and checked and its engaged and everything, then boom that loop just goes away and I see the perfs aren't engaged anymore.

If the perfs are being ripped, the film is somehow being held on the take-up side (is the door clamping on the spool, does the spool spin freely?)

yes it does. The perfs aren't ripping, but u sr little dents next to them when the film comes loose.
Maybe I'll video tape this to give a better visual.
I bought this cheap a couple years ago and it actually needed to be taken apart down to the main spring by me to get working again but strangely, it did run with ought the loop loss. I'm pretty sure this thing has been dropped though.
I appreciate the help and suggestions Dom
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#6 Tyler Purcell

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Posted 23 January 2017 - 01:14 AM

Video the problem, I think you'll see it right away. I think your issue is related to the height of the main sprocket. I bet it's slightly off and the film is following the guides and falling off the sprocket.
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#7 Peter Gilabert

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Posted 07 February 2017 - 01:03 PM

Problem solved.
Believe it or not, it wasn't the heighth of the sprocket, although that's super important.
It was just a matter of ordering that silly little snap-on triangle shaped guide that fits on the entrance to the sprocket.
It helped the film stay high enough to keep close to the pawl and sprocket so- no lost loop/jam.
What a relief...I was getting pretty frustrated there.
K-3 people sent me one for $5 and voila, good to go.
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#8 Tyler Purcell

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Posted 07 February 2017 - 02:10 PM

Interesting, makes complete sense as well. I didn't know that was missing on your camera. All of those guide components are necessary for the camera to function properly.
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