Archived posting to the Leica Users Group, 2013/12/18

[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]

Subject: [Leica] IMG: From Long Ago
From: bill at (Bill Grimwood)
Date: Wed, 18 Dec 2013 10:51:21 -0600
References: <>

Jim did you ever know Bob Pitcock from Huntsville who used to come up and
run tests at Tullahoma for NASA?

Bill Grimwood

-----Original Message-----
From: at
[ at] On Behalf Of Jim
Sent: Thursday, December 12, 2013 4:19 PM
To: LUG at
Cc: Olympus Camera Discussion
Subject: [Leica] IMG: From Long Ago

As a young engineer, my first assignment was to calculate the nozzle plate
shapes for a flexible plate nozzle for the AEDC 16-Ft Transonic Wind Tunnel,
then under construction.  The shapes had to vary from a simple contraction
to a Mach 1.6 contour, and the process had to be done by 16 pairs of jacks,
without over stressing the steel plates.  And, other than the basic
supersonic shapes calculated by folks at Cal-Tech, it was all done on Friden
and Marchant desk calculators.

To move the jacks from contour to contour, a series of steps were chosen
that stayed within stress limits, as determined from curvature calculations.
These steps were then stored in L-shaped pegs on a mechanical memory drum,
with the shapes transferred to cam-driven readers and fed to vacuum-tube
amplifiers which supplied the driving signals to the ball-bearing screw

Bear in mind that this was all done in the early 1950s.

This photo, taken from my technical report, shows the mechanical memory drum
and the console which contained the drum drive system, the transfer plate,
and the individual jack amplifiers.  The console and system were designed to
our specs and provided by an engineering company whose name does not come to
mind after 60 years.

Memory has come a long way since then. :-)

Jim Nichols
Tullahoma, TN USA

Leica Users Group.
See for more information

Replies: Reply from jhnichols at (Jim Nichols) ([Leica] IMG: From Long Ago)
In reply to: Message from jhnichols at (Jim Nichols) ([Leica] IMG: From Long Ago)