[GreenKeys] Remembering Numbers

[Jones, Douglas W]

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Sent: Friday, April 18, 2014 6:56 PM
To: Ron Kolarik
Subject: Re: [GreenKeys] Remembering Numbers

You guys might want to take a look at an oil that may still be in
production, MIL L-23699.
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I looked it up:

-- Lubricating oil, aircraft turbine engine, synthetic base
 
-- primarily used for aircraft engines, which have a nominal viscosity of
-- 5 centistokes at 100 Deg. C and which are typically made with
-- neopentyl polyol ester base stocks.

Don't use it in Teletypes.  For two reasons:

a) synthetic oils based on esters are notorious for attacking acrylic
and ABS parts.  In the Model 33, the case is ABS and there are several
acrylic parts inside -- mostly holding contact wires.  It also attacks PVC
and many paints.

b) the viscosity at 100 F (40 C) is about half that of KS7470.  We really
care about the cold viscosity because most of the Teletype mechanism
is not running hot, merely warm.  You don't burn your fingers poking
around in a properly maintained Teletype that you've just turned off.

                     Doug Jones
                     jones at cs.uiowa.edu