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Old Feb 8, 2008, 5:27 AM   #1
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I have two second-hand lenses which have enough oil on the blades of the iris to either stop or radically slow the closing action of the iris. I am toying with the idea of trying to get the blades clean, but my dollar investment is under $50 total, and I expect it will take several hours to do the work, if it even possible.

I am fairly handy with tools, and I have a lot of spare time. Some spanners will likely be needed to open the lens. I believe I can make them out of tempered brass, cut, filed, and soldered.

One lens is a Sears 50mm f/2.0. The other is an Albinar 135mm f/2.8. Neither is a prize, but both have excellent characteristics otherwise, so my conservative nature won't let me casually toss the lens into the trash.

What advice, instructions, suggestions, or sympathy can someone offer to me?

Old Engineer
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Old Feb 8, 2008, 12:01 PM   #2
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OE,
both of these should be a walk in the park to anyone having basic skills. here's basic instructions. i've been into 50mm,200mm and 300mm. basicly they are the same. just mark where the internal focusing module is at when the lens is focused to infinity.. i haven't been into the ap but it should be part of the main lens module. also, there are spacers inside some modules.. be careful you get them back in correctly.. you may not need a spanner. if the lens does not protrude above the ring with the spanner notches then a straight bladed knife will work.. to get the lenses themselves out i use a childs suction cup throwing dart. if you are in the US i'll be happy to drop one in the mail to you if you want to wait a day or two.. i had to buy a set. also take pix as you disassemble. the aperture will probably be contained in it's on module and should not have springs in it.. mark it where it comes apart and either take it apart at a fully open or closed position.

let me know an addy if you want a cup..

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Old Feb 8, 2008, 12:02 PM   #3
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oops, guess you would like the link
http://www.texasbostons.com/dismantle/index.htm

roy
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Old Feb 9, 2008, 1:45 AM   #4
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Roy, I appreciate very much the instructions you posted. I believe I understand what to do with one exception. You advise to mark the focusing column at the point it is set to infinity focus. It would seem those parts would be inside where they cannot be seen. Perhaps you can explain that particular point so a novice will understand what is intended.

Yes, I would like to have the suction cup. As a kid they were all around, but I haven't seen one in decades.

Thanks, Old Engineer
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Old Feb 9, 2008, 11:33 AM   #5
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OE,
i have the addy. thought you'd PM me with it but... go ahead and delete it in your post just for safety.
what are you going to reimburse me for???? a stamp?? i say just forget it..

when you take the name ring off and the filter ring you'll see the lens module mark it and the barrel with a scratch so you know it's place.. these are all a little different but you shouldn't have a problem with a non-macro prime.

roy
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Old Feb 9, 2008, 4:37 PM   #6
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Roy, Thanks for the caution. I have complied. I wondered about the revelation. Also, I now understand about the marking problem. I may be back to you when I get started tearing down the lenses.

My plan for making spanner wrenches is quite simple, and, in case someone else wants to know, here is what I envision doing.

I have worked with various small brass extrusions over the years, in fact have a resident stock of small bars, flats and tubes. I have used these for my inventions requiring prototypes for demonstrations to my possible buyers. In the area in which I livethe brass partsare available at Ace Hardware stores, and similar outlets.

I will use a brass flat bar about one inch by 1/16 inch. I will solder to it two brass rods about one and one-quarter inch long at the appropriate distance apart. Then I will use my Dremel tool with a one inch grinding disk, and make points that will fit into the slots that need twisting. I will smooth off the two points I just made as best I can with various grades of abrasive papers, down to at least 600 grit. Lastly, I will fuse a bit of solder on the polished tips. While the solder is still liquid I will wipe it off the tips with a wad of cloth. I think enough solder will remain that the tips will be coated lightly. My theory is that "Murphy's Law" will probably intervene, and the soldered tips will be less likely to gouge any glass that gets in the way. I will probably test that supposition on a drinking glass, maybe made of gass and also of plastic, to test the point's ability to make scratches.
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Old Feb 9, 2008, 6:34 PM   #7
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i purchased THIS set for about $25shipped. i see he's gone up..

for cleaning the lenses i suggest latex gloves and denatured alcohol or white lightning or everclear. i found acetone to dry too fast. for the blades i'd say an acetone bath. the gloves because of all the oils on your hands. also when reassembling the lens module that only the two inner surfaces need to be clean.
please take pix of the ap as you take it apart as the only one i've been into is the one on my 500 and it's 2 inches across.. i also use Selvyt polishing cloths. best thing in the world. get them dirty just throw them in the wash.. also, it's REAL easy to drop a lens..

believe me about the gloves,
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