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Fabio
Tinkerer
Username: Fabio
Post Number: 1
Registered: 09-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, September 30, 2009 - 12:30 am: | 
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I am trying to remove the top of a Zenit 3M.
I have to unscrew (lefthand) a ring on the winding lever but unfortunately it seems that it is really stuck. I had no possibility with rubber, nor with pliers (it was already quite marred, I had just worsened the thing...).
What I am afraid is that I can apply a lot of force (torque) and fear that I can damage something "inside": as the ring is so stiff I am applying all the torque to the shaft and every gears or what else is connected to it.
Any help to a beginner on how to get rid of such rings???
Many thanks to all!!!
Here is an image of an unscrewed ring (from: http://markhahnphotography.com/russian/3m_focus/3m_focus_adjustment.html )
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Fabio
Tinkerer
Username: Fabio
Post Number: 2
Registered: 09-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, October 01, 2009 - 01:38 am: |
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Tried again: no results. I've tried plain torque, hammering; tried to heat the ring. No way. I can make the whole thing rotate and feel what are probably a couple of gears that "jump the theets" (sorry don't know how to explain in english... I hope you can imagine what I mean).
I could get to the take-up shaft from the bottom (image) but this doesn't help: blocking the shaft actually doesn't avoid the stress on the gears inside.
Here's what I found as the possible interiors (this is from a Zenit E, probably not much different from the 3M): actually the take-up axes rotates in the opposed direction.
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Msiegel
Tinkerer
Username: Msiegel
Post Number: 137
Registered: 03-2008
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, October 01, 2009 - 09:33 am: |
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Fabio,
Just had a look at my 3M. I can confirm that the take spool runs in the opposite direction of the winding lever - meaning that sprocket wheels and takeup spool run in opposite directions and the film runs under the takeup spool when winding. Not uncommon at all.
It looks like the actual spool is missing on your picture - have you taken it off or was there only the shaft? If it is missing someone had the camera apart and maybe messed up the part you want to screw off.
I try to make a pic from mine and post it later.
Martin |
Msiegel
Tinkerer
Username: Msiegel
Post Number: 138
Registered: 03-2008
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, October 01, 2009 - 09:50 am: |
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Here it is
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Fabio
Tinkerer
Username: Fabio
Post Number: 3
Registered: 09-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, October 01, 2009 - 11:10 pm: |
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Many thanks Martin but...yes, sorry I should have mentioned that: I took the spool off to try to apply a reaction torque while uncrewing the infamous ring on wind lever. Unfortunately, as the spool shaft is not the "same piece" as the wind lever shaft, this was not of help: I can lock the spool shaft but applying torque to the ring I'm stressing the gears inside beyond their limits.
Fabio |
