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Don Congdon
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, April 19, 2005 - 02:55 pm: | 
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I am working on a Retina IIIc shutter that's a bit sticky on the slow speeds. I have successfully removed the ring nut, shutter speed dial, lens mount, and shutter cam disk to expose the shutter itself. I know that the slow speed escapement is somewhere on the right side, but I am unsure exactly which gears are the likely problem or what is the best approach to clean them. Several people have said just to drop a few drops of naptha into the gears, but I am concerned that this approach will just dissolve the hardened grease and deposit it somewhere else or just allow it to reharden after the naptha evaporates.
I am also concerned that if I use too much naptha, I will contaminate the shutter or diaphragm blades or, even worse, the rear lens elements. Is it possible to drop in some naptha and then remove it in some way along with the grease it dissolves?
Is it sufficient to clean the gears or should any lubrication (i.e. graphite) be included?
Thanks! |
David Nebenzahl
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, April 19, 2005 - 10:52 pm: |
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You'll get other answers, I'm sure. One thing though: I'd advise against using graphite. While it is an ideal lubricant--light and non-gummy--the problem is that it'll inevitably get onto the surface of a lens. (Ask me how I know this: I ended up doing a lot of blowing out a shutter with air and cleaning lens surfaces).
I won't say anything more since I'm not familiar with the Retina shutter. |
Winfried
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, April 20, 2005 - 12:00 am: |
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It is correct that shutters run mostly without any lubricant, i.e. without oil and/or graphite. Sometimes I add a tiny amount of graphite to the drops of lighter fluid.
The problem with the Compur shutters is that they have large cutouts in the shutter bottom plate under the speed escapement. Flushing the speed escapement with lighter fluid in many cases will cause the blades to stick together, since the grease is - as you pointed out correctly - just washed away and NOT removed.
The proper method is to remove the speed escapement from the shutter assembly. Unfortunately the Compur shutters are adjusted by proper positioning the speed escapement, and it is almost impossible to get it exactly back into the position it originally was (it has oversized holes). So you will have to readjust the shutter after disassembly.
If you do it the easy way, prepare yourself to a long sequence of shutter blade cleaning. I had good success with flushing the blades with lighter fluid, wipe them until they seem dry, fire the shutter several times and wipe away the excess lighter fluid again and again. After two or three of these procedures I let the shutter rest for a week or so and fire it at the top speed (1/500). If there is the slightest sign of sluggish movement (the blade movement should hardly be visible at 1/500) I repeat this. |
rick oleson
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, April 20, 2005 - 06:20 am: |
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Look at this picture: it's from a Rollei, not a Retina, but it's close enough:
http://rick_oleson.tripod.com/28c-detail.jpg
If the blades themselves are clean, and you want to clean up the slow speeds without removing this gear module from the shutter, find the star wheel and pallet (noted on the photo), and apply ONE DROP of naphtha to the holes where their shafts come through the top of the frame (near the red arrows). I use an old draftsman's ruling pen to apply the naphtha; these are getting hard to find any more, but you can use a small paintbrush or (if you're careful) the points of a tweezer to apply a suitable amount. With reasonable care, this is so little solvent that it will evaporate before it can get into anyplace where you don't want it to be.
Usually this will bring back the slow speeds without disturbing the adjustment.
rick : ) = |
Don Congdon
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, April 20, 2005 - 01:20 pm: |
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Thanks for the useful comments! I think I'll give Rick's suggestion a try first and then tackle the harder ones if it fails.
If, as Winfried says, I accidentally get naphtha on the shutter blades, what is the best way clean them? Do I add more naphtha and then wipe it off, or do I just keep wiping and firing them until they are dry and residue free? What it the best tool to wipe them so they don't get bent or otherwise damaged? What risk is there of the rear lens element getting contaminated with the naphtha/grease mixture?
How involved is it to remove the entire slow-speed escapement? I realize getting the timing right might be a problem, but what is the basic mechanical difficulty of removing/replacing it?
Many thanks! |
rick oleson
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, April 20, 2005 - 03:10 pm: |
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If you get naptha on the blades, first just try letting it dry off. If there is no oil down there it won't hurt anything... if there is oil and grease, the naphtha might dissolve some of that and spread it into the blades, in which case your best bet is probably to wet a cotton swab with naphtha and wipe them clean, following with a dry swab to remove as much residue as you can. Repeat until they look clean and hope for the best.... a really proper job of cleaning out the blades and actuating ring is kind of a lot of work. You will probably get some oily residue onto the rear glass if it's still in there, which is not ideal; you'll have to clean it well (anything you leave is magnified by the front elements and very visible later) when you're finished.
To remove the timing escapement, there are just 2 screws, one at each end of its frame. once out, you can bathe it in naphtha to your heart's content. the trick is that when you put it back in you'll have to fiddle with it to get the speeds right.... fussy, but certainly doable. |
Steve
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, April 26, 2005 - 02:54 pm: |
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I had to clean gummy shutter blades recently on my Retina IIc. If you set the aperture at f22 this will very much reduce the chance of any liquids getting splashed on to the rear lens. |
Murray
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, May 31, 2005 - 02:36 am: |
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Hello:
How applicable is the lazy cleaning technique to the Retina Reflex S? $$$ to have someone do it.
A triangular piece of leather(ette) has already fallen off the raised rectangular lens mount area. I see a screw there, probably another underneath the remaining leather triangle and one on the ring at the bottom, but I'm hesitant to open it. I don't do well with extra parts.
Murray |
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