[LargeFormat] CLA

[Richard Knoppow]

----- Original Message -----
From: "Loren Wohlgemuth" <lorenzo@pacifier.com>
To: <LargeFormat@f32.net>
Sent: Friday, January 24, 2003 2:41 PM
Subject: [LargeFormat] CLA


> Howdy all,
> Im on the west coast of the US, just north of Verna, well,
a lot north,
> near Astoria.  I've posted my lineage before but mostly
lurk.
> Question:  Is there anywhere a written treatise on how to
CLA a lens?
> I've got a couple that definitely need all that but I'm a
bit
> apprehensive to just jump in and unscrew just to see
what's inside.
> Also, should I succeed in dismantling said lens, what
lubricant should
> one use?  30w? 50w? or spit?
> I just know that someone here has that information tucked
away in an
> efile and would love to guide  a neophyte CLA'r along.
>
> Loren in Astoria
>
  Even though this is now an old thread I might add a little
having cleaned many shutters.
  The best cleaner is no longer easily available. This is
1,1,1,trichloroethane. It is selective for the greases and
oils found in shutters but doesn't dissolve paint or most
plastics. Unfortunately, its considered an environmental
hazard and is hard to get.
  Probably the best combination of solvents are naptha,
lighter fluid will do, followed by very pure isopropyl
alcohol. In the USA Ronsonol lighter fluid is quite pure and
works without leaving a residue. 99+% Isopropyl can be found
in drugstores. Don't get the 91% or rubbing alcohol, the
water will remain after the alcohol evaporates.
  Ideally, the speed regulator gear train should be removed
and cleaned separately but that is a delicaet job and not
really necessary.
  Remove the lens cells from the shutter. Most shutters have
a removable front panel, this should also be removed. Pour
ligher fluid into the shutter and blow out using canned air.
If you have a small metal container the shutter can be
soaked for a couple of minutes and then blown out. Flush
with fresh fluid and blow out again. Two or three
repititions will insure against residue on the shutter and
iris blades. After using the naptha use the alcohol in the
same way. Really pure Isopropyl will not leave a residue.
  The shutter should be allowed to dry out thoroughly.
Compur, most Wollensak shutters, Kodak shutters can be dried
with gentle heat but don't apply heat to Ilex Universal
shutters and many really old shutters, the iris and
diaphragm blades are made of hard rubber (Ebonite) which
will melt.
  Ilex shutters are supposed to run dry although I've found
a very sparing amount of light lubricant helps keep the
retarder mechinism reliable.
  Compur and other regulated shutters should have a very
small amount of watch oil or other non-gumming,
non-migrating, light oil applied to the trunions of the
regulator gears and to the palet. Suitable synthetic oil is
sold under the name Nyoil, a Google search will find it.
I've also found suitable light synthetic oil in model
railroad stores.
  Apply the oil with the end of a match stick or with the
tip of a very fine brush. You can place a drop of oil on a
dish and brush it out with the brush, them pick some up with
the tip. Watchmakers have special tools for applying
measured amounts of oil but I don't think they are necessary
for shutter work unless you are doing a lot of them.
  Some sliding parts of shutters can be greased with light
silicon grease of the sort sold as Lubriplate in the USA.
Light Molykote is also good and is what Deckel used to
recommend for Compur shutters. For late type Synchro Compur
shuters, as used in Rolleiflex E's and F's a small amount of
light Molykote should be applied to the drive spring.
  NEVER oil diaphragm or shutter blades.
  Dial set Compur shutters have a position adjustment for
the retarder mechanism. It is set to make 1/10th second
exactly on. The other speeds should then fall in as marked.
  Note that most shutters do not have any real means of
adjustment. Ilex Acme and Universal shutters can be brought
in by a tedious juggling of the strength of the main spring
and the return spring on the retarder.
  Kodak shutters can sometimes be cleaned without
disassembly since most of the mechanism is exposed when the
lens cells are revoved. I still recommend taking the front
panel and speed cam off.
  Generally Compur shutters can be brought into pretty good
agreement with marked speeds. Sometimes the old dial set
type need to have cam adjustment or they will have 1/5th or
1/10th second repeat in two places. This doesn't happen with
the later (1930) rim-set type or later Compurs.
  Compound shutters have a tension adjustment screw for
speeds. If clean and in good condition they are surprizingly
accurate and reliable. Some Compound shutters have fiber or
Ebonite blades, so be careful and gentle with them.
  Wollensak shutters are generally well designed and built
and can be brought to life by cleaning.
  Kodak shutters, which seem to have a bad reputation among
some, are actually very rugged and reliable. Sometimes the
main spring is tired lowering the upper speeds. I don't know
of a source for these.
  The Compur factory manuals specify about five types of
lubricants but they are identified by Compur part numbers or
occasionally by their German trade names. You sort of have
to figure out what they are.
  Old lubricants tend to become gummy with age. Modern
synthetic oils are much longer lived and also have viscosity
which is less temperature dependant.
  Prochnow's Rollei Technical Report has a good section on
Compur Rapid shutters which is applicable in general
technique to other Compur shutters. A reprint Compur factory
manual covering mostly later series lenses is available from
Petra Keller http://www.camerabooks.com and from John S.
Craig at http://www.craigcamera.com
  I've done business with both and they are very reliable.
  BTW, John Craig has a short piece about Peter Palmquist on
his site. Palmquist was killed by a hit and run driver.
John's dauter was killed by a drunk driver a few years ago
so I think he has an especial feeling about this.
---
Richard Knoppow
Los Angeles, CA, USA
dickburk@ix.netcom.com