View Full Version : Industar 22 Aperture Diaphragm Reassembly
So I got my hands on a really nice-looking Industar-22, with good, clean optics and decent cosmetics. The only problem is, the aperture ring was stiff to the point of being almost impossible to turn. Never one to realistically assess my own level of skill, I figured I'd just take it apart and get that old, nasty grease out of there.
Problem is, when I got the lens disassembled, and the grease cleaned off, my hand slipped and I ended up with a pile of aperture blades and no idea how to put them back together again. I've gotten as many as five blades back on, putting them back together in the open position, but then I'm stuck. I have to slip the last three under the others without knocking the first five out of their little holes, but every time I try, I end up unseating the other five and I'm right back where I started.
Does anyone else who's done this have any advice or tips, or should I just call this a thirty-dollar lesson and move on?
I sympathise. My trouble was only coagulated grease on the pointer and lever outside the actual lens assembly itself.. Soon fixed that.
As for re-assembling diaphragms, I have had experience and it isn't nice to listen to. However patience and time work.
I did see an idea where the poster put an old 12V PC power supply fan on the side of a cardboard box that had a piece of fly screen or similar over a hole on top where you were going to work. The idea was to create a down draft to keep gentle pressure on the leaves as you slipped the one under the other at the end of assembly. Sounded good to me but I've not needed to do it (yet!)
Another idea from that occurred to me to put a magnet in the bottom of the box (it's got to be pretty strong, but they're out there) and it would pull the blades down the same way. You wouldn't need the hole and fly-screen that way.
One lens beat me. It was a Summitar with 12 blades and a hex aperture. The iris is cone shaped and the tech I finally gave it to admitted he was short of swearwords too with that one.
I've taken these lenses apart on several occasions but always been extremely careful not to disturb the iris blades for fear of the exact problem you face! I have a feeling that there must be a simple technique, if fiddly, to replace them. I doubt the factory had people spending hours swearing in order to assemble them originally! Perhaps Brian Sweeney has experience of doing this job and can advise?
Got it back together. I put a refrigerator magnet under the diaphragm, and carefully slid the remaining three blades in by gently lifting the last one in line up with a jeweler's screwdriver, and pushing the next blade under it with another jeweler's screwdriver. Actually, I found that they don't have to all stay in their holes, as when you put the piece that holds them down/opens and closes the diaphragm in they can be nudged gently into place with a screwdriver. After that, the only hitch I ran into was losing the tiny screw that holds the face of the lens in place. Luckily I had a junk I-10 lying around that I could cannibalize parts from.
Thanks everyone for your comments, advice and encouragement. I knew I'd never forgive myself if I let this thing beat me. It really wasn't as hard as I thought it would be. Then again, when I tried it again today, I wasn't tired and frustrated with a couple of beers in me, so that might have something to do with it.
Hey! Great going. The fridge magnet under the lens would be so much simpler and plenty strong enough. Well done.
As for the 'think juice' it can sometimes help a troubled and frustrated mind;)
vBulletin® v3.6.8, Copyright ©2000-2013, Jelsoft Enterprises Ltd.