5cm Summar won’t tighten into place when extended

[UghhhJon]

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Hello! I picked up a 5cm Summar f/2 that’s in great cosmetic shape. It was recently CLA’d and worked well the first few times I used it, but now when I extend it and turn it counter-clockwise to tighten into place, it just spins freely. I noticed that the back of the lens tube that the 3 bayonet tabs are on is loose and just spins. Is there a way to tighten this piece? The screw that’s there is fully tightened. Thanks!

[jerzy]

does the lower part (marked X) rotate when you rotate the upper part of the lens? If not then the 3 screws (one shown, orange arrow) are mnot tighten enough. If it rotates - does the black locking ring on the lower part rotates? If not then the locking scerw (black arrow is missing/lose. You might know it - there is only one position when the lens locks. When is properly assembled the arrow on the tube marked with my blue arrow shall match the mark on the mount. Tghis is position when you shall extract the lens then then lock as the other arrow on the tube shows. But I am quite sure that it does not match on your lens anymore. 

Extend the lens as much as you can, then look at rear side if all 3 notches on locking ring match the cutouts in the mount, they are different so there is only one position when they match. Then you may extract tube a bit more and lock. And if  arrow marked blue does not match the mark on the mount losen the 3 screws (orange) and rotate upper part to match.

in your particular case the screw marked with black arrow is missing. I believe this is M1,4 mud screw. Locking ring shall have a mark how to position it.

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Edited April 28, 2024 by jerzy

[UghhhJon]

Hi Jerzy, thank you so much! The part marked x wasn’t rotating with the upper part of the lens and tightening that screw marked with the orange arrow worked perfectly. Thanks!

Edited April 29, 2024 by UghhhJon