Date: Wed, 16 Nov 2005 16:36:48 -0800
Reply-To: John Bange <jbange@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: John Bange <jbange@GMAIL.COM>
Subject: Re: Cracked Slider Hub Pictures
In-Reply-To: <86476e250511161202w52e871fcv82ba45b75c6d81d5@mail.gmail.com>
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On 11/16/05, Loren Busch <starwagen@gmail.com> wrote:
>
> Bad initial design. What idiot put a square corner on a opening in a piece
> subject to lateral stress? Can you spell 'Comet Jet'?
>
Heh. Yeah, that's right, same deal there with square windows. I suspect the
square cutouts in the 3-4 synchro slider hub are the work of a junior
process engineer whose work was signed off on by an inattentive senior
mechanical engineer. Process engineers seem to gravitate towards squared-off
edges on things because it's easier to gauge whether the manufacturing
process is properly calibrated. My father used to work on missile systems
for Hughes Aircraft in the 80's. The DOD made them "second source" many
missile parts from Raytheon, a very poorly run company. One day Hughes
tested a $60 million dollar missile and the rocket motor failed to ignite.
It dropped off the F-14 like a bomb and smashed to pieces on the desert
floor. Investigation showed that the rocket safety failed to disengage. The
safety was a 12-toothed spring loaded rack held in place by a 6-toothed
pinion gear on a stepper motor. The motor would rotate exactly twice, then
the arm would snap free under spring pressure and hit the switch igniting
the rocket. The very end of the Hughes version of the rack was rounded. The
Raytheon version was squared off and, as a result, it in effect had a
THIRTEENTH TOOTH on the end of the rack. This extra tooth stayed caught on
the pinion, preventing motor ignition. The Raytheon process engineers cut
corners by discarding details on the drawing they felt were superfluous
(such as rounding the end of the rack) thus saving the company money. I bet
they felt real smart, having saved the company maybe a quarter man-hour per
part. My father said that fully half the machined parts they second sourced
from Raytheon where similarly "process engineered" into uselessness.
Everything from Simple angle metal brackets incompletely shaped to fit in
carefully specified places, to steel anchor points with squared off corners
instead of properly rounded to fit MILITARY STANDARD underwing weapon
stations.
Back to obligatory Vanagon content: GoWesty has some pretty good pics of
failed 3-4's
<http://www.gowesty.com/3-4syncrohub.html>
--
John Bange
'90 Vanagon - "Geldsauger"
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