[pure-silver] Re: rollei not fixed

----- Original Message ----- 
From: "DarkroomMagic" <info@xxxxxxxxxxxxxxxx>
To: "PureSilverNew" <pure-silver@xxxxxxxxxxxxx>
Sent: Tuesday, November 30, 2004 1:48 PM
Subject: [pure-silver] Re: rollei not fixed


> Shannon
>
> How did you measure the 1/60 time? How is the shutter 
> performing at other
> speeds? Try to work the shutter at all speeds a few times 
> (3-5), and test
> again!
>
> I believe, the viscosity increase of aging grease in the 
> shutter is the
> reason for slowing shutters. This grease needs to be 
> cleaned out and
> replaced every couple decades or so. Ask if they did that.
>
>
>
>
>
> Regards
>
>
>
> Ralph W. Lambrecht
>
>
    Most shutters require very little lubricant. A very 
light oil, similar to watch oil, is used on the trunions of 
the gears in the speed regulating escapement. Very light 
grease is used in some shutters on a few sliding parts. 
Modern lubricants are synethetics which have a much wider 
temperature range than animal or petrolium based lubricants. 
They are also much more resistant to oxidation and 
evaporation. Many shutters work fine when dry, i.e., no 
lubricants. As lubricants age they can become gummy and also 
thicken with collected fine dust. Using the shutter keeps 
the lubricants distributed but the synthetics do not tend to 
migrate so shouldn't need working even after many months.
   The only shutters I know of that require excercize are 
Ilex Universal shutters. These are rather crude shutters 
used on large lenses. Ilex recommended firing the shutter a 
couple of times before making an exposure. Ilex shutters are 
meant to run dry.
   The Compur shutters used on Rolleiflex/Rolleicord cameras 
are capable of being quite accurate and are very reliable 
and rugged. However, they must be cleaned properly. Proper 
cleaning requires partial disassembly, not just flushing the 
assembled shutter. Its critical that there be no dirt or 
grease on the shutter blades. Proper cleaning is more work 
than a lot of repair people want to do to shutters are often 
given only a superficial cleaning.
   While it is possible for the springs in a shutter to be 
fatigued they should not be just due to age. Springs do not 
become weak with age or even from being compressed or 
extended. Weakening comes from metal fatigue caused by many 
cycles of tensioning or compressing and releasing. As long 
as the spring is not stretched beyond its elastic limit it 
will not take on a permanent set.
    The main reason for fast speeds being slow is dirt on 
the shutter blades or in the blade driving rings. Slow 
speeds are off due to dirty lubricant in the retarder which 
in most shutters is a clockwork mechanism with an escapement 
and toggle. Slow speed regulators often have some form of 
adjustment, in Compurs its the exact position of the 
retarder, which is a separate assembly. A properly cleaned 
and lubricated shutter should go on for years before needing 
additional service.
   Also, a good Rollei person will check out other things on 
the camera such as focus coincidence between finder and 
taking lens, and adjust it if necessary. he/she will also 
check out the winding mechanism.
   Rolleis are well designed and very well constructed, 
relatively easy to work on compared to a lot of inferior 
cameras.
   The lens being "fairly" clean bothers me, either its 
clean or it isn't. Cleaning lenses is also not brain 
surgery.

---
Richard Knoppow
Los Angeles, CA, USA
dickburk@xxxxxxxxxxxxx 

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