[Leica] Leica Camera body metallurgy

[Andrew Nemeth <azn@nemeng.com>]

Been emailing off list with Frank Dernie about the use of Titanium
and other alloys for camera use.

As it may interest LUGgites, and with Frank's permission, allow me 
to re-post the following to the list:

N.B.  Here 'ally' means "aluminium".

>Subject:     re: Ti = titanium?
>Sent:        29/6/19 7:53 PM
>Received:    27/6/99 6:51 AM
>From:        Frank Dernie, FrankDernie@compuserve.com
>To:          Andrew Nemeth, azn@nemeng.com
>
>Hi Andrew,
>The problem here is weight verses longevity.
>Early Leicas were hand made from brass sheet with an ally sleeve covered in
>vulcanite. The brass is painted matt black inside and gloss black and
>nickel plate outside. Chrome plate came later but when the IIIc came out
>with diecast ally shutter crate and top plate surface finishing began to
>start to be critical for longevity. Many wartime cameras which did not have
>adequate underplating have blistering chrome.
>Ti strength to weight ratio is good but manufacturing is expensive because
>it is slow and difficult.
>Steels are good but heavy as are brass and bronzes (almost essential in the
>focussing helix for long life and good feel).
>Light alloys corrode whether ally or mag based, ally is the best because it
>is well protected by being anodised and is cheap and easy to machine. 
>I am not in the least surprised that Leicas are ally diecastings and use
>brass in the focussing helix. These are the best material for the job.
>Surprise surprise!
>Many plastic materials are robust and light and are suitable for cameras
>shells but, contrary to popular belief, are too expensive to use in low
>volume production. Their thermal expansion is too high to use them in
>critical locations, though many still do!
>Of all the materials I use Carbon fibre composites would be the best for
>the structural parts of the camera and locating the lens elements. Its
>thermal expansion is negligible. Brass would still be needed in focusing
>mounts, some of the shutter and rangefinder mechanisms, and bearings.
>Problem? cost and cosmetics. The cost would be hugely more than the current
>Leicas and the surface, whilst trendy and liked by some is not very hard
>and scratches easily.


I note that Minolta have started to use stainless steel for more
than just the lens mount flange.  If you have a look at the detailed
review of the Minolta Maxxum 9 in 'Popular Photography' Mar 99, at
pp.84 and 86 there is mention of the extensive amount of SUS 304 
used for the body front and top plates.  A first?...

Extrapolating a few years into the future, imagine a solid stainless 
steel, fully manual, built-in motor R9!  Now *that* would be a camera 
to behold!

Regds,

Andrew Nemeth
www.nemeng.com