[rollei_list] Re: OT: Question re shutter CLA and Ronsonol
- From: John Jensen <jwjensen356@xxxxxxxxxxxxx>
- To: rollei_list@xxxxxxxxxxxxx
- Date: Wed, 12 Jan 2005 21:11:54 -0800 (PST)
Many years agao (about 1963) I talked with a friend, a
non-engineer, who took a job with Castrol in the San
Francisco area. He was very enthusiatic about his
job, his new company, etc. He jabbered about the high
quality of Castrol, that it contained "whale sperm
oil". After I picked myself off the floor, I
explained to him that, if anything (I still had my
doubts), it might contain 'sperm whale oil'. I left
it at that.
John
--- Jerry Lehrer <jerryleh@xxxxxxxxxxx> wrote:
> Richard,
>
> Very goooood!
>
> BTW, I still have a few cc's of sperm whale oil,
> which
> was supposed to be a non-oxidising oil to be used in
> fine shutter mechanisms. Most oils will oxidise and
> turn
> into "varnish", which is the perpetrator of most
> shutter
> stoppages or slowdowns.
>
> There is an oil called Nyoil, made in the great
> whaling
> port of New Bedford, that used to be sperm whale
> oil, then was JOJOBA oil, but I don't know what it
> is
> now. Non-oxidising oils can probably be synthesized
> these days.
>
> Jerry
>
> Richard Knoppow wrote:
>
> > ----- Original Message -----
> > From: "Ardeshir Mehta" <ardeshir@xxxxxxxxxxxx>
> > To: <rollei_list@xxxxxxxxxxxxx>
> > Sent: Wednesday, January 12, 2005 10:20 AM
> > Subject: [rollei_list] Re: OT: Question re shutter
> CLA and
> > Ronsonol
> >
> > >
> > > Still, at one time I did try to unscrew the
> front elements
> > > of the
> > > Tessar lens to try and get to the shutter in
> order to
> > > clean it. I did
> > > manage to unscrew the front element using a
> rubber stopper
> > > (I don't
> > > have a lens wrench) but the shutter is
> apparently behind
> > > TWO lens
> > > elements, and I couldn't unscrew the second
> element. So I
> > > just put the
> > > front element back.
> > >
> > > I am wondering about the slot in the left bottom
> side of
> > > the lens, and
> > > why this camera has it. Maybe you can enlighten
> me. A
> > > little lever
> > > protrudes therefrom, which can also trip the
> shutter. The
> > > camera is an
> > > early model Automat. Through this slot some bits
> of the
> > > shutter
> > > mechanism are actually visible. I can squirt
> vast amounts
> > > of Ronsonol
> > > into the shutter though this slot. I can also
> drain
> > > dissolved stuff
> > > out, and at one time quite a bit of sludge came
> out though
> > > it after the
> > > Ronsonol had loosened it up. Bits of black
> solids also
> > > came out -
> > > specks of stuff like maybe tiny paint chips? I
> thought I
> > > was succeeding
> > > in cleaning the shutter off completely, in fact
> - so much
> > > stuff came
> > > out. But apparently I was wrong, for after the
> Ronsonol
> > > evaporates the
> > > shutter still sticks, though not nearly as much
> as it used
> > > to.
> > >
> > > But the question remains in the back of my mind:
> what
> > > happens after the
> > > CLA? Won't dust and dirt get into the shutter
> again,
> > > through this slot?
> > > My 2.8D doesn't have such a slot, and its
> shutter seems to
> > > be totally
> > > sealed against the elements. Why, then, does
> this one have
> > > such a slot,
> > > though which dirt can get it? I am mystified.
> > >
> > > Cheers.
> >
> > You managed to get the front element off the
> lens without
> > removing the front cell. Its useful to be able to
> do this
> > because it allows cleaning the surfaces inside the
> cell but
> > it is not something that needs to be done more
> than once in
> > twenty years.
> > Compur shutters are constructed so that the
> mechanism is
> > not exposed when the lens cells are removed. In
> order to get
> > to the works one must remove the front cell and
> take off the
> > front cover of the shutter. That allows removal of
> the speed
> > ring. Once that is off its possible to remove the
> retarder
> > mechanism. That is the worst offender in a shutter
> which is
> > behaving irregularly. The regulator is a
> clock-work
> > mechanism. Its cleaned by soaking it in Naptha
> followed by
> > pure alcohol. Once cleaned its lubricated by
> putting the
> > tiniest amount of fine oil on the trunions of the
> gears and,
> > perhaps, a touch on the pallet. Suitable oil is
> available as
> > Nyoil and the finest grade of Lebell silicon oil,
> available
> > at hobby shops. The retarder is replaced and its
> position
> > shifted until 1/10th second is exactly correct.
> The other
> > speeds should then be accurate.
> > Further cleaning really requires removal of the
> entire
> > shutter from the camera and its disassembly. Its
> important
> > to have a drawing of the thing so you can see how
> to get it
> > back together. The shutter and diaphragm blades
> are cleaned
> > in solvent and the shutter blades polished to
> remove any
> > trace of residue. The shutter is then
> re-assembled. Some
> > Compur instructions indicate that a trace of light
> grease
> > should be used in a couple of places but I was
> told by a
> > fellow at Compur several years ago to just leave
> it dry.
> > The top speed of Compur and most other shutters
> is the
> > _effective_ speed for the full shutter aperture.
> Since the
> > shutter has a finite opening and closing time this
> is rather
> > faster than the total open time as measured for a
> small stop
> > or by a small sensor at the center of the
> aperture. For
> > Compur-Rapid and Synchro-Compur shutters the
> marked top
> > speed is about 80% of the total opentime. i.e.,
> for a
> > shutter marked 1/500th second the measured top
> speed is only
> > about 1/400th. I think Compur specifies somthing
> like
> > 1/380th as the limit. Compurs should be within
> about +/- 5%
> > for speeds to the top speed but that one can vary
> as much as
> > 20% from the nominal speed.
> > The use of effective speed markings is also
> found in
> > focal plane shutters, particularly Speed Graphic
> and Graflex
> > cameras because the shutters in them are not very
> efficient.
> > It is possible to measure the _effective_ speed
> of either
> > a leaf or FP shutter using the little Calumet
> tester but it
> > requires careful set up so that the light
> intensity at the
> > half open and half closed points fall at the
> threashold of
> > the sensor.
> >
> > ---
> > Richard Knoppow
>
=== message truncated ===
Other related posts:
