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David Nebenzahl
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, January 09, 2004 - 08:52 pm: | 
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My latest acquisition, a 75mm Westar (???) lens in Pronto shutter (4 speeds, 25-200), wants to be taken apart to be cleaned, but I can't figure out how. It's probably from a 6x6 or 6x4.5 folder, with a focussing front cell. I can get the front cell off easily enough, but it looks like the middle cell is holding the rest of the shutter together, and I can't get it off. At least, I've tried unscrewing it, but it doesn't budge.
Does this middle cell unscrew, or am I barking up the wrong tree? I thought about taking the four screws on the back of the shutter off, but didn't want to get it apart and not be able to get a tightly-screwed part off.
Help! |
Winfried
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, January 10, 2004 - 03:33 am: |
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First, on the later Pronto shutters (Pronto, ProntorS/SV/SVS), do NOT loosen the four screws in the back before you have managed to open the shutter cover. The aperture module will come off, but there is a nasty hairspring inside the shutter which is held in place by one of these screws and it's a pain to get it back into place (and of course this is impossible without opening the shutter).
On some Pronto shutters the wavy ring nut around the shutter collar can be removed without unscrewing the second lens element mount. But in most cases this has to be removed. Maybe the thread has stuck. If there are no notches on the thread collar, maybe you can file in two notches 180 deg apart so you can apply a spanner wrench. |
David Nebenzahl
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, January 10, 2004 - 01:17 pm: |
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So it is threaded as I thought. I'm one step ahead of you: I already drilled 2 little holes to use my pointy spanner, but it's still not budging. I'm squirting lacquer thinner around the rim with a syringe. My experience with these kinds of stuck things is that they eventually come loose with enough soaking in solvent and application of brute force.
In this case I can't cut notches because the collar is pretty thin, and the notches would cut into the focusing threads and make a mess of them.
By the way, it seems like a nice little shutter. Not as many speeds as others, but enough to get by on, and seems to work well mechanically. |
Winfried
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, January 10, 2004 - 03:04 pm: |
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You will find Pronto or Prontor shutters (the latter have a full range of speeds) on many older german cameras. Compurs were only used on high-end equipment. I have seen hardly any Pronto/Prontor shutters where the blades were not gummed up. On the other hand, most japanese shutters including some early Copal shutters rather followed the Prontor design than the Compur design, so the basic ideas behind it don't seem to bad. |
Kostas
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, July 20, 2005 - 05:33 am: |
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Hi to all! I am facing the same problem with the same lens (a westar in a pronto shutter removed from a dacora digna camera). I would like to know if David had any luck unscrewing the middle element as I have been unable to do it so far. My shutter, instead of the usual noches on the middle element housing, has a very tiny hole which might contain a tiny screw inside (or not-my smallest screwdriver can 'feel' anything inside).
Strange thing is that I have searched a lot everywhere but noone mentions that kind of situation in a pronto shutter. Is it a screw that has to be unscrewed to remove the housing? Or is it a kind of notch for the spanner? In that case where is the other one? Of course I can drill one but I want to know if someone had any luck with this task.
I have already posted in another forum and the answer was to try to unscrew the whole middle-element housing. That was impossible so far. |
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