[LargeFormat] Compund Shutters

[Richard Knoppow]

----- Original Message ----- 
From: "Clive Warren" <cocam@blueyonder.co.uk>
To: <largeformat@f32.net>
Sent: Tuesday, May 20, 2003 4:49 PM
Subject: Re: [LargeFormat] Compund Shutters


> At 9:18 am -0400 20/5/03, Les Newcomer wrote:
> >I've looked under the hood a couple of times, but if your
intending
> >to send me a bag of parts in hopes of putting Humpty
back together
> >then you've got the wrong guy.
> >
> >Not that this is news to you, but the gear train usually
found on
> >the right side of say a Graphex is replaced by a rather
simple
> >compression system for the low gears and a smaller train
for speeds
> >above 1/25  hence the term compound.  The dial at the top
moves the
> >cylinder position for the slow speeds and cuts it out of
the circuit
> >at the higher ones.
> >
> >Les
>
> Les,
>
> Thanks for the info. I haven't looked under the bonnet yet
so you
> won't get a jiffy bag in the post just yet ;-)
>
> Now that air driven gizmo - I am assuming that over the
years the
> clearance between the piston and cylinder bore opens up a
bit through
> wear. So fast shutter speeds on the slow range may be a
little
> difficult to remedy?
>
> Cheers,
>         Clive
>
  I don't think it wears much. There is an adjustment for
the mainspring which sets the speeds. These shutters are
quite accurate and repeatable. They don't seem to have all
the mechanical hysterisis that the Ilex shutters have.
  Presumably, the speeds are affected by altitude but
probably not a lot if you don't live in Denver. Compounds
were built by Fredrick Deckel Co. beginning about 1912 to
around the mid 1980's. Bausch & Lomb built them under
license in the teens and twenties. The Deckel versions are
better constructed (IMHO) than the B&L ones. They make a
quite satisfying "thunk" when working right.
---
Richard Knoppow
Los Angeles, CA, USA
dickburk@ix.netcom.com