Hello,

I am trying to revive an old Yashica Minister rangefinder (very similar to the Lynx line). The focus on the camera is completely frozen, I cannot move it from the infinity mark. There are no signs of impact damage or improper disassembly. I suspected dried focusing helicoid lubricant and soaked it in lighter fluid, hoping that it will penetrate and loosen the threads, to no avail.

I have the lens/shutter assembly out of the camera, the focusing scale ring removed from the helicoid and still cannot see a way to get the helicoid moving.

Any ideas anybody?

Thanks,

Jan

By Dan Mitchell on Tuesday, February 24, 2004 - 01:35 pm:

Is there possibly some sand or other "stuff" in the threads? I've had some cameras where a rangefinder mirror came loose, fell down into the helicoid and then got ground up. It was almost impossible to unscrew the helicoid to fix it.

By Jan Dvorak on Tuesday, February 24, 2004 - 02:07 pm:

Hello Dan,

The RF mirror was loose inside the top housing (now fixed), but so it was on another Minister which works perfectly. I think the glue that Yashica used to affix these mirrors was not very good and a lot of them simply worked themselves loose.

Nothing else is in the threads, that I can see. There is no evidence of sand, or other foreign material. If the camera was dropped, it would have happened in the eveready case, I don't believe that would have caused the helicoid to lock up.

Any other hints?

Many thanks,

Jan

By Scott on Tuesday, February 24, 2004 - 06:08 pm:

Try a little heat.

What I would do, if you do have the shutter assembly removed, and have removed the lens elements, is warm it up a little. This has worked for me when fixing 1950s cameras with stuck focus threads. You don't really have to make it hot, but if you can warm the whole thing up a bit, the hardened grease will usually soften up enough to allow you to unscrew the parts just using your hands. If just warmth doesn't do it, try it again a littler hotter.

I put the stuck pieces on top of an upside down pie pan in a large, covered wok over a low flame for a couple of minutes, then grab the piece with a dish towel and unscrew the parts while it's still warm.

By Howard on Wednesday, February 25, 2004 - 01:31 am:

Hi Jan, for what its worth I own several old Yashica's and I have never come across one with hardened lubricant. Most old Yashica's seem to focus smoothly regardless of whatever other problems they may have. I feel something may have fallen into the thread or perhaps it has corroded.
It's just a thought. Good luck!

By Jan Dvorak on Wednesday, February 25, 2004 - 11:39 am:

Thanks everybody!

This also is one of many Yashica rangefinders that I either own or have come across - the first one with a frozen helicoid. I will try the heat. I think if anything fell into helicoid threads there would at least be some movement, but I have none at all; literally frozen solid. Everything else works fine and the camera is in close to mint (as much as I dislike that word) condition - it would be a pity if I could not fix the focus...

Any other ideas are still appretiated, wish me luck!

Jan

By Jan Dvorak on Wednesday, February 25, 2004 - 10:48 pm:

SUCCESS!

I am happy to report that the operation was successful and patient is on the way to recovery. It was the heat that did the trick - I let the camera sit within 4 inches of a 60w table lamp (with the selenium meter window covered, just in case) and after about 1 hour of basking in the heat the helicoid responded to my efforts. At first the movement required a lot of force, after 5 minutes of soaking the helicoid threads with lighter fluid and letting it penetrate into the grooves, movement became a lot easier. Probably a little more tinkering and adding a proper helicoid lubricant will finalize the repair. Next, the rangefinder mirror will be re-glued, rangefinder re-calibrated and all should be well again.

Thanks for the hints,

Jan

By Howard on Wednesday, February 25, 2004 - 11:24 pm:

Well done. I have found that a product here in Australia "Shellite" which is probably sold worldwide dissolves the old grease really quickly and completely. I had tried a variety of things on an old Petri thread with little success, but the "Shellite" did the trick in a couple of minutes. I used synthetic bicycle grease afterwards and it worked really well.