I just got a collapsible Summicron and it was in need of a good CLA.
Living where I do and having some previous experience with Jupiter-8 and 3's, I though I could do the cleaning and re-lube myself.
Luckily, I have the same type of mount that Justin Low's Summitar here: http://justinlow.com/articles/repair-leica-summitar
And since the top-cover on the focusing mechanism never budged, I removed the 3 bottom screws and got the helicoid separated that way instead.
Unfortunately, while taking out the optical block, I managed to pull out the inner-tube (which covers the felt and the ball-bearings).
The push/pull mechanism of the optical block was very very tight anyway, actually to the point where you unscrew the lens from the camera if you try to collapse the lens.
- That can't be normal, right?
So, after cleaning the helicoid and re-assembly, the focus was pretty smooth and nice.
However, after struggling to get the inner tube trough the hole, with the ball-bearings, the pullout/twist was very very hard again......and now the focusing action
was becoming harder and harder as well.
What do you do with the felt-trap on these lenses?
I wonder how the heck they were able to assemble this in the old days, the felt is around 1mm thick and it is too thick for he inner part that holds the optical block to pass without jamming.
I am thinking about just replacing the felt with something else, it seems the only function of this felt, is to prevent creeping and wobble when in the folded position and out-position, before locking it. (in the locked position, it stays stable with or without felt).
The ball-bearings rest magnetically on two nipples, which themselves have to small springs in the bottom-end. It is very easy to slip the inner-tube over those, a slight pressure with a small screwdriver is sufficient.
Anyway, can someone tell me a little about the felt that was inserted in these lenses?
Suggestions for (DIY) replacement materials?
Will the pressure of bungled felt effect my focusing-smoothness? (I think it does, focus is now very tough on mine and it feels like it need another cla, even though it is just cleaned and lubricated!).
A tip: For anyone trying to clean the aperture-ring on the collapsible summicron or summitar: Be extremely careful! Once you have taken the two screws out on the aperture-ring, the black controller that moves the aperture blades, sits loosely on top of the blades.
One knock and you will have to re-assemble all the blades again, see the photos at:
In other words: The two screws on the aperture-ring is the only thing that is holding the blades in place.
Do you lubricate aperture blades? I mean, not the whole blade, but the notch at the end that goes into the holes inside the aperture-casing?
This is after all a moving part, will it not need some kind of lubrication to prevent too much friction against the casing? (I was not planning to lubricate it, but since I am in the process of cleaning the lens, I thought I should ask).
I hope someone here who has been down these lenses can give some pointers on the felt-trap and possibly the aperture-blade question.