Archived posting to the Leica Users Group, 1998/08/14

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

Subject: Re: [Leica] Format units question
From: "Glen M. Robinson" <gmrobinson@imation.com>
Date: Fri, 14 Aug 1998 09:00:48 -0500

TTAbrahams@aol.com on 08/14/98 12:17:10 AM
Part of my job is to design optical test instruments such as optical
interferometers.  The machine shops that I use here in Minnesota only use
English units.  However, they use mils (one thousands of an inch) instead
of fractions of an inch.  I learned the hard way not to give machinists
engineering drawings containing metric units.  Translating all the metric
units into English units was not fun.  By the way, Tri-X is my favorite
film too.

Glen Robinson



Glen, your point on temperature and volume is well taken, and,although
being
born "metric" I can use the ounce and pint measures in the darkroom. Where
the
British or " Imperial" system falls apart is in machining. Trust me. it is
easier to machine in metric than in 1/1000 of 2,54 cm. At least I know that
a
full turn on the feedwheel of my small lathe is 1,00 mm movement with the
cutting tool, not 0,0384". On the bigger lathe the handwheels are
calibrated
in Imperial and this unit has a calculator epoxied to the tailstock!!!.
Temperatures in Centigrade has a relevance, at 0 degressC the water is
freezing and at 100 it is boiling, and at 20C+ you can develop Tri-X for
10min
in D-76.
Metrically yours,
Tom A