Ideas to remove stuck lens retainer ring

[Leo.G (Leo)]

I have a beautiful Olympus 1.5 times extension lens, ED glass, very nice quality screw on the front of a lens unit (with suitable adapter). It came in with an old Olympus IS1000 I picked up at Salvation Army a while ago (sadly like many cameras the battery door retainer clips have been broken off, highly likely by staff (or customers) in the system who try to force doors shut (I've seen it too many times and watched staff do it, occasionally stepping in just in time)).
Anyway (sorry, I get lost when I haven't slept), the front lens element has just one spot of minor fungus on it which I'm not too worried about but the rear element has considerable fungal growth I'd like to clean up. To access the rear cell I have to remove the front lens.
I have the correct tool but no amount of suitable force while my son held the lens would get the retainer ring to budge.
I have no idea if these items were possibly assembled with thread locker but I can't see any trace of it.
Any ideas would be appreciated and being a plastic body even small amounts of heat are out of the question.


This unit with an adapter fits a 300mm Nikon lens I already have and the beauty of these units was they don't have to be stopped down like a conventional teleconverter (which I also have (2 times)) and they provide a great quality alternative to the teleconverters because they don't amplify artifacts sitting in front of the lens itself instead of between lens and film plane (wait, is that even a thing now? damn, I must be getting old). Oh, between lens and body.


I'm familiar with stripping down lenses having done numerous over the years including complex electronic lenses I've picked up cheap online (because of fungus) for my Nikon). I'm not cheap or tight, I've been on disability pension far too long.

Plastic bodies I'm not overly fond of, knowing applied forces can render the thing totally useless which I'd hate to do.


I'm considering making myself another custom removal tool (for each lens I may need it on because they will be built as non adjustable) where there will be an outer perimeter ring to remove any chance of slipping across the glass with the legs as I'm always highly conscious of the possibility of it happening whenever I come across a stuck retainer ring (not my first and likely not my last).


Were it alloy I'd consider some type of machining the ring out but I'd destroy the thing I'd imagine, any swarf would destroy the glass.

[rbronca]

Weapon of choice for these type of things https://www.bunnings.com.au/haron-10...rench_p4900118 90+% of the effort is getting the strap lined up around the object. I use mine regularly.

[Leo.G (Leo)]

Thank you, I have strap wrenches here I could try and chain link units I wouldn't use on a lens. I'll try one tonight.
I didn't think to use it to hold the lens extension body but need to be careful in this place because it's plastic bodied.


I've designed a better, safer tool to turn the rings (adjustable). If I get out to the lathe I'll turn the necessary round parts up. It's basically 12mm x 25 aluminium bar separated in two pieces with 2 6mm sliding guide pins and a central double ended reverse threaded adjuster in the middle allowing screw rotation adjustment. the design incorporates replaceable external guide rings (sections) to provide an external guide so the thing can't slip and slide and scratch a lens and two hardened, ground pins to fit in lens ring grooves.
I have a lot going on at the moment but I'll hopefully get to making the tool soon, it's a better design than anything I can purchase.
Sadly I do too many lenses. I have a thing about buying cheap lenses when I come across them which are already very mouldy with the thought if I pull them apart and clean the glass I get a cheap lens, if I damage them I lose little. I've so far resuscitated 3 good Nikon lenses I got very cheap and stripped right down to get working, including one unit which wasn't moulded but was locking up when zooming in and out.
I'm not cheap, I don't repair lenses for anyone but myself, I'm broke and my ability gives me access to better quality and range of lenses than I could normally afford.