Fitting issue on the Yashica-12 TLR

[HHS]

Hi all,

A few months ago, I got a somewhat worn-out Yashica-12 TLR, I could restore and I have been already tested with film with success.

But I couldn't solve one problem:

as soon as I put on the lensboard and operate the crank, the tab of the Shutter Cocking Plate Assembly that moves the main spring lever on the Copal shutter seems also to lift the entire lensboard 1-2mm upwards. When lensboard is screwed tight, this creates resistance on cranking and noise on the lensboard when the crank is turned. Without the lensboard, the film transport runs quietly and smoothly, as it should.

I have checked the position of the Copal Shutter housing - all washers and spacer sits correct. I checked the main spring lever - should be o.k., I checked the clearance between the lens board and the tab of the Shutter Cocking Plate Assembly - no contact. I don't really understand where the fault lies, it seems to me somwhow that while cranking it lifts the Main Spring Lever of the copal, and with that the whole lensboard.

But why? And how to solve? Any Ideas?

Thank you in Advance
Heiko

 

[Dan Daniel]

Photos please.

 

[HHS]

Photos please.

This shows how the tab of the cocking plate assembly pushes the main spring lever against the shutter housing and lifting it all up:




Also some videos:

 

[monopix]

You've identified the reason - the cocking plate is trying to push the shutter cocking lever beyond it's normal travel. Either the shutter is not fitted properly and needs rotating around a few degrees or the cocking plate is bent.

From your picture, it looks like the shutter is not seated properly - it looks tilted - but maybe it's just the picture. But I would check you have the pin on the back of the shutter properly located into the slot on the front standard.

 

[HHS]

You've identified the reason - the cocking plate is trying to push the shutter cocking lever beyond it's normal travel. Either the shutter is not fitted properly and needs rotating around a few degrees or the cocking plate is bent.

From your picture, it looks like the shutter is not seated properly - it looks tilted - but maybe it's just the picture. But I would check you have the pin on the back of the shutter properly located into the slot on the front standard.

Thank you.
I checked the proper seating of the shutter several times - the pin is properly in the slot. The cocking plate is flat as it should. The shutter and lens barrel seats tight as it can be.

But indeed there seems to be an "Over Travel" - the rotation linkage lever driven by the crank, which moves the cocking plate will travel till the end on its rail. From some videos and trials I guess usually it should stop 1-2mm before, but here it travels more and begins to lift the whole lens plate. Additional factor: the metal tabs are quite soft, I can see notches made by contact of the levers.







While repair and check with an empty film roll the winding mechanism blocked - then maybe I put too much force on it, which affected the inner mechanism of the linkage arm. Oh my....

 

[Dan Daniel]

Check the tab for bending. And think about bending it to the position that will give you the right travel. This part of the Yashica shutter cocking is prone to this. Watch out for creating new interference like the tab being slanted on the top edge and finding a new place to bind.

 

[monopix]

I don't have one here in bits to look at and I'm not dismantling my '12' but, if memory serves me, the part in this picture should slide so that, when it gets to the end of the travel of the cocking lever, it allows the ring to continue to rotate a little. Maybe it's stuck?

 

[HHS]

I don't have one here in bits to look at and I'm not dismantling my '12' but, if memory serves me, the part in this picture should slide so that, when it gets to the end of the travel of the cocking lever, it allows the ring to continue to rotate a little. Maybe it's stuck?

View attachment 406369

It does move - a bit stiff, maybe some cleaning and lube could help, but it does move.

 

[monopix]

It does move - a bit stiff, maybe some cleaning and lube could help, but it does move.

Looking at your video again it does look like it's moving but maybe there is insufficient movment? Otherwise, I'm out of ideas. I've fixed a lot of Yashica Mats and I'm sure I've seen a similar problem but don't remember the cause.

 

[HHS]

@monopix @Dan Daniel
I could improve it a lot today with a Dremel.

Before:

After:

I also had to adjust the eccentric washer below the ratchet gear plate, as the set lever (the arm which has this half circular movement driving the shutter cocking ring) touched it already, which must not - danger of bending it! There also some more screws, so it seems you can adjust the travel of the set lever - but couldn't figure it out yet:


I could also fix a problem with the shutter button, the shutter blocked often when a cable release was mounted, keeping the shutter open until you wiggled the shutter button. Fixed now.

Feels really nice now.

But there is still something bugging me: One of the former owner of the camera encountered a poblem I had myself and can replicate: following the procedure of loading film in official camera manual)ä, the crank tends to block after first image. Only opening the back, cranking backwards and pressing the shutter button solves the blockade. It does happen with empty film spool and with a full film spool when the crank is facing towards the lens.

When I crank backwards before closing the back, everything works as it should.

I wonder if this all is another fault that
needs to be fixed somehow; or my test conditions are unrealistic; or it's simply down to the instruction manual? It also says cranking backwards cocks the shutter - which we know is not the case.

 

[250swb]

Yashica TLR's are not meant to be repaired, simply looking inside says they are the filmiest construction that will work reliably, until it doesn't. I have two that have failed and are junk, it's cheaper than the time spent chasing faults to just buy another, and hope that one works. I mean stamp pressed gears made from thin sheets brass are not encouraging. The lenses are great, but other TLR's are better.

 

[monopix]

Yashica TLR's are not meant to be repaired, simply looking inside says they are the filmiest construction that will work reliably, until it doesn't. I have two that have failed and are junk, it's cheaper than the time spent chasing faults to just buy another, and hope that one works. I mean stamp pressed gears made from thin sheets brass are not encouraging. The lenses are great, but other TLR's are better.

Just for balance I have to say I have owned several and, although I've had some issues, they are very repairable and no more unreliable than any other camera of similar age.

 

[monopix]

@monopix @Dan Daniel

I also had to adjust the eccentric washer below the ratchet gear plate, as the set lever (the arm which has this half circular movement driving the shutter cocking ring) touched it already, which must not - danger of bending it! There also some more screws, so it seems you can adjust the travel of the set lever - but couldn't figure it out yet:

I think that eccentric washer is just to hold the focus arm in place. It should just extend over the bottom edge of the arm to stop the arm coming off the runner. It's nothing to do with adjusting the set lever. I don't think there is any adjustment of that.

 

[HHS]

I moved the eccentric just so that there is now at least less 1mm between zo the set lever.

And indeed, the screws are for adjustement of the focusarm - shame on me. I noticed there were a bit loose and tightened it - I think I have to check now that the right arm is at the same level like the left arm - it seems to me, but maybe there are 0,5-1mm difference which my eyes can't catch?

Any idea how to check and adjust this without completely breaking the adjustment?