Fix of loose collapsible part of lens?

[ForestCap]

The collapsible part on my KOMZ Industar-50 is so loose, it goes down to the extended position by the pull of gravity when pointing down.

The lens is much heavier in comparison with my KMZ collapsible I-22, maybe it's made of brass or other denser material? Anyway, the the extra weight made the loose problem worse.

Is there a way to fix it?

 

[02Pilot]

The friction is applied by a piece of felt stuck around the inside of the fixed part of the lens. If you remove the nose of the lens, you can slide the barrel out the back and access it. Remove it (it's probably compressed with age, and the glue won't be very sticky any more) and cut a replacement from new felt from a craft store, preferably slightly thicker. Stick the new felt in, reassemble, and you're done.

 

[ForestCap]

Thanks for the tips!

For now I stick a piece of thin tape around the collapsible neck to increase the diameter by a tiny bit, now it stays there as wanted. I will disassemble and change the felt after finish shooting this roll.