Really small screws on the back of a Hexanon 57mm 1.4

[dsiglin]

I apologize if this isn't the right subforum for this. I made an educated guess.

This past Saturday at a local antique store I discovered a very good condition Hexanon 57mm 1.4 lens. Lens takes great photos but I noticed the rear element rattled a bit when I moved the lens around. I tightened the rear element down by screwing it back in some (perhaps a 1/4" turn clockwise). However I hear something small tinking around inside still. I found a guide to disassembling the bayonet mount from a similar Hexanon lens, however the screws used in mine are VERY tiny. I tried a 1.4mm flat head but that is still too large and the screws seem rather "soft". I'm afraid of stripping them.


So, here's a photo of the bayonet mount. There are the set of four larger screws and four smaller screws that I need to remove. Hope you guys can give me some pointers. Thanks.

 

[tirediron]

Go to a tool-supply, hobby, or electrictronics shop and ask for a set of 'jeweller's screwdrivers".

 

[dsiglin]

Ok, that's probably the best bet. I have a set of stinking small screwdriver heads but I guess they aren't small enough. Thanks.

 

[dsiglin]

So I filed down a screwdriver I had so it fit the small screws. I removed the back and sure enough some spring comes out of nowhere. Also a ballbearing. I think that ballbearing is the culprit. I'm not sure what the spring was for but it was very small. Oddly enough everything works even without the spring, at least as far as I can tell. Aperture still works across the entire range. Maybe the spring was part of the EE mechanism?
Turns out the rear element group was loose. It was a matter of tightening it up some, cleaned it off a bit while I was in there. As far as "repairs" go this was super simple but still fun. Thanks for the help guys. I'll probably end up selling the lens since it overlaps with my canon fd 50mm 1.4.