dcshooter
Member
I have a Cooke Amotal 2" f/2 in m42 that I received very dirty and am trying to CLA. I have the rear successfully disassembled, but I can't for the life of me get the front ring off to remove the front group and clean the interior and aperture diaphragm..
It appears that the knurled ring on the front and the name/retaining ring for the front element/group are all one piece, but I can't for the life of me get it to turn either counter clockwise or clockwise. Applying heat, acetone, and MEK have not worked at all. I don't see any set screws holding it in either.
It is clear thatthe element can be removed, since there are cleaning marks on the rear surface of the front element, presumably form a past disassembly. I'm wondering if the last chucklehead managed to cross thread the ring or did something stupid like apply superglue before reassembling.
If anyone has managed to get this one apart before, could you just confirm that I am on the right track in trying to unscrew the front, or is there something obvious I am missing? If it weren't such a valuable lens, I'd be tempted to immerse the whole thing in solvent to see if there is any threadlocker that might dissolve, but I don't want to run the risk of fouling the elements, especially if I never manage to get them out to clean them.
It appears that the knurled ring on the front and the name/retaining ring for the front element/group are all one piece, but I can't for the life of me get it to turn either counter clockwise or clockwise. Applying heat, acetone, and MEK have not worked at all. I don't see any set screws holding it in either.
It is clear thatthe element can be removed, since there are cleaning marks on the rear surface of the front element, presumably form a past disassembly. I'm wondering if the last chucklehead managed to cross thread the ring or did something stupid like apply superglue before reassembling.
If anyone has managed to get this one apart before, could you just confirm that I am on the right track in trying to unscrew the front, or is there something obvious I am missing? If it weren't such a valuable lens, I'd be tempted to immerse the whole thing in solvent to see if there is any threadlocker that might dissolve, but I don't want to run the risk of fouling the elements, especially if I never manage to get them out to clean them.