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Colin Melhuish
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, January 06, 2005 - 02:47 pm: | 
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Can somebody tell me if there's a "magic" method to assemble the diaphragm blades is a Prontor SV shutter from an Agfa Isolette? A couple of the blades became loose during use and following dissassembly I now have a box of bits that I'd really like to be able to put back together :-)
(It's a Solinar equipped shutter so it really deserves to be put back into action!)
Cheers, Colin |
rick oleson
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, January 06, 2005 - 03:11 pm: |
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Boy, I'd like to know that too. There MUST have been an easier way to do it when they were running these things down the assembly line. For me the magic ingredient is mostly patience. |
Dan Mitchell
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, January 06, 2005 - 06:21 pm: |
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Yeah, patience. 
One trick is to use a tiny amount of light grease in the holes to hold the blades in position. You then flush out the grease with solvent after assembly is complete. |
Colin Melhuish
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, January 07, 2005 - 05:23 am: |
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Gulp....... well, if you guys don't have any patented slick tricks for putting these beasties back together then it looks like I'm in for a few cosy evenings in with a pair of tweezers and a stiff drink ;)
I might try the light grease suggestion though, as when the blades fell out a few of them were still held in place by some sort of oil or grease, and they did seem a little more controllable while they were clinging together.
I'll let you know how it goes. Don't hold your breath......
Colin |
rick oleson
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, January 07, 2005 - 06:32 am: |
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Do that if it works for you; use as little as you can get away with. I personally have a sort of emotional block against it: Here I've just spent all this time taking these all apart to individually clean them perfectly dry, to get every last bit of grease and oil OFF of them.... no way am I going to put more back on and then try to clean it out after reassembly, if I was doing that I wouldn't have disassembled them in the first place. But people do report that it helps, and maybe that's the 'magic trick'.
: ) = |
Henry
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, January 07, 2005 - 08:48 am: |
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One trick that has worked for me, don't know if it is applicable in this case, is to stack coins up until they are the right height for the blades to rest on as I position them. |
Dan Mitchell
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, January 07, 2005 - 11:14 am: |
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I'm with you rick, I don't really like using grease in the diaphragm. With enough practice it isn't needed.
The prontor shutter repair manual says not to put any lubricant in the diaphragm, but also says that they used a special assembly grease at the factory. I have a copy of the Valera shutter repair manual and he also suggests using just a tiny amount of grease.
One other trick is to assemble the diaphragm by putting the cover plate front side down on the workbench. Place the blades into the holes spread out like a "fan" and then slowly work the blades in towards the center. Even the blades up so they match the maximum aperture then carefully lift up the cover and place the shutter base down on the cover upside down, then flip the whole thing over and install the cover screws. Any blades that don't seat correctly can be pushed into place with a toothpick. |
Winfried
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, January 08, 2005 - 03:40 am: |
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I think I have found a method which is very close to Dan's description.
In some other cases (lenses) I found that it is close to impossible to assemble the blades down in the lens barrel. I had good results by pulling out the blade actuating ring and arranging the blades on that ring outside the lens barrel. It is easy with the first 8 or 9 blades of a set of 12. To reassemble the other ones you have to push the blades already arranged properly somewhat outward so you can place the guide pins of the left over blades into their respective slots and gently push them between the other blades. When all blades are arranged, try to arrange their upward guide pins in intervals as even as possible. Hold the ring with the blades with two fingers and put it back into the lens barrel from below. If there are any links (holes for pins etc) to the outer aperture dial try to get this link into proper position (but this may be corrected later). Gently push the blade actuating ring against the fixed blade ring inside the lens barrel and turn over. Most blade guide pins will find their place in their respective holes on the fixed parts. The other ones can be snapped into place by gently wiggling the blades a bit. |
Ed
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, January 08, 2005 - 11:02 am: |
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This can be trying and many tilmes requires several tries. First--make sure you know up from down--usually they are not the same. I then clean the blades, the shutter were they sit and the top ring. The first few go in with ease. When the hard part comes, I take and eye dropper and put a drop of the solvent on the blades already installed--this helps hold them in place. From there it is a matter of slipping the next blade in an so on. Usually it is necessasry to add a little more solvent as it does evaporate as you work. The key is PATIENCES. The other method is to remove everything except the dia. blades and bath it--I use an ultrasonic cleaner. |
Colin Melhuish
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, January 10, 2005 - 04:08 am: |
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Success at last! I used a small spot of moly grease on the pivot hole of each blade when reassembling them and got the diaphragm back together first time! It then took *a lot* of flushing with solvent to remove this grease, but eventually I ended up with a fully working shutter :-) In retrospect, maybe a much lighter grease or oil would have had the same effect.
I expect that, as Dan says, they possibly used a similar technique employing "assembly grease" on the production line when they made these things.
Many thanks for all your help and suggestions!
Cheers, Colin |
