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Wernerjb
Tinkerer
Username: Wernerjb
Post Number: 127
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, April 27, 2007 - 12:07 pm: | 
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Every now and then it happens, either the front or the rear group of a RF camera lens won't unscrew, no matter if you try heat, solvent or sheer force. Which means that you cannot clean the lens and/or the shutter or aperture blades between the two lens halves.
At present I cannot separate the rear lens group of a newly bought old disfunctional Ricoh 35 L from its seat, even my solid homemade steel tool broke (in any other respect the repair is no problem,
cf https://kyp.hauslendale.com/classics/forum/messages/6899/5836.html )
Is there any solution to that problem I do not know of? Any help is appreciated, W. |
Rick_oleson
Tinkerer
Username: Rick_oleson
Post Number: 255
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, April 27, 2007 - 07:34 pm: |
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Hi Werner:
I have found this problem sometimes too. In particular, the lens cells in the Mamiya interchangeable-lens TLRs seem to be extremely tight. In some cases with these, I have wrapped the lens cell with rubber (like from a bicycle tire inner tube) and then placed over that an automobile radiator hose clamp (the stainless steel kind that has a screw on the side and grooves for the screw threads in the strap). After tightening the clamp very tight, I struck the head of the screw several times with a small hammer to loosen the lens. I have had to do this enough times that it is in my camera repair notes....
In less extreme cases, I have had success with wrapping 2-sided adhesive foam tape around the cell and using that to get a better grip than I could get with a piece of rubber.
Neither of these tricks will work, though, unless you have good access to the lens cell - it won't work in the rear, for instance, where you are inside the camera. |
Wernerjb
Tinkerer
Username: Wernerjb
Post Number: 128
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, April 28, 2007 - 02:52 am: |
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The camera I am working on has been in the hands of sombody else who left traces of unsuccessful unscrewing attempts. I have now separated the shutter assembly incl. both lens halves from the body and meanwhile the front lens group (with bigger notches!) is off and the shutter plus the blades are accessible and working. But as the camera design is somewhat odd (a maximum number of interconnected levers is used to operate the RF, for instance, and the selenium meter's coupling is very complex) I do not think I would want to open it up again. The problem is that the shutter housing has levers, flash wires and cams mounted to it which makes it difficult to obtain a firm grab. But now that I know I am not alone I feel a lot better. This is to say I will definitely try your method(s) and give the shutter module a sound CLA, many thanks for your encouragement, Rick, W. |
Wernerjb
Tinkerer
Username: Wernerjb
Post Number: 129
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, April 28, 2007 - 04:13 am: |
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HOORAY, the tape-clamp cobination did the trick!
It tried double-sided adhesive tape first, but it turned out to be too soft because the rim by which you can grip the rear lens group is just a few millimetres high, and the strap of the clamp, 16-25 mm in diameter, is at least twice as high as that. But I found that a sort of tape by which years ago kids taped their bicycles' handlebars with turned out to be the right material. Instead of a hammer I used a piece of wood to make the punch softer (I did not want to crack the lens), and it worked! W. |
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