Leica LTM Baseplate (Leicavit) latch too tight. Easy fix?

Leica M39 screw mount bodies/lenses

coelacanth

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I hope the knowledgeable here can help me out.

I just scored a Leicavit for IIIf/g for pretty darn good price. It fits and advances just fine on my IIIg.

However, I think the latch action to close/open the lock is a bit too tight to my confort. By Leicavit itself, the opening lever operates fine. The IIIg and its regular baseplate (Believed to be the original that came with the camera. Shell and top plate S/N matching as well) work together fine with just the right amount of resistance closing and opening. My guess is that that the holding disk thing on the Leicavit needs to be ever ever so slightly looser, giving less friction to the metal retainer tip on the camera side.

I see there is a flat head screw on the Leicavit holding the locking disk in place. Is it as simple as ever so slightly loosening that? Or should I expect somthing more involving? Just not sure if that's a good practice or not as I've never done it before.

I can lock the Leicavit to the camera with some amount of force using my thumb, but definitely quite a bit more torque needed compared to the regular plate. I just don't want to put much of stress to the internals of the camera.

Any ideas of tips? Thanks for your help in advance.
 
I would leave it to a competent repairman. Often the axis of the take-up spool needs some adaptation too so that the Leicavit will tension the camera with one jerk. My Leicavit fits perfectly to my IIIg, but not to my IIIc's.

Erik.
 
Thanks Erik for your insight. One thing to note: the Leicavit fits fine to IIIg with no push back or force needing to keep it in place. Leicavit will stay flat and even to the body just fine. Only the closing the locking mechanism is tight.
 
Only the closing the locking mechanism is tight.

I remember mine had the same problem. It took the repaiman only a few minutes to make it smooth, but I did not see what he exacly did! In any case he has put some grease on it, it still is there, on the inside on the moving lid that locks the Leicavit to the camera.

Erik.
 
Thanks Erik.

OK I'm reporting back.

It turned out, the retaining disk was sitting ever so so slightly sitting higher (sticking out further from the Leicavit base) than the standard base plate. I'm talking 0.1mm or less of a difference, but it was just enough to give a bit of extra friction. I took the disk out, and found out there is a shim right below it. I see there is a extremely slight recessed area on the back side of the disk, looks to be for smaller diameter shim to be in place. I am no repairman, but my guess is that very fine tuning of shim hight was done back in the day when each Leica was fit and adjusted by hand. Plus, like Erik said, probably the shim was bit dry. I replace the shim with ever so slightly thinner one, put super thin layer of grease (grease alone on the original shim wasn't good enough) and voila! Locking/unlocking is now smooth.

Just in case someone searches for similar problems in the future...
 
Congratulations, well done. Happy shooting! Do you have any other c or f cameras to try it on? I think that a SM Leicavit will fit only one body, but I am not sure about that.

Erik.
 
Here is a pic of the assembly.

24457811452_b348ec009d_c.jpg


The black shim is the original one. Notice the retaining disk has recessed spot for different shim to be in place (maybe again, i am not expert). After few tries, I used a plastic shim that I had in place of the black one, making the height of the retainer identical to the one on IIIg baseplate. And there are tiny identifier markings on the retainer, probably done in the original assembly. Gosh they really built them one by one back in the days.

Erik, I am no expert, but I've read elsewhere that the SM Leicavit (SYOOM) was made for IIIf, eventually IIIg becoming compatible when it came out. IIIc should be same overall size as IIIf, but maybe there are some slight differences in those details, maybe? I could imagine repairman or Leica service (back in the days) could adjust those shims to fit correctly. Maybe someone more knowledgeable than myself can comment on IIIc fitment.
 
Thanks for posting this. I recently acquired a IIIf w/Leicavit here at RFF and am experiencing the same problem. When I sat with Youxin, he mentioned this is a common issue. I wasn't aware of the shims. It doesn't bother me so much to make an adjustment but this is good to know. Thank you very much for the detailed pic.
 
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