Sujet : Re: Suspension losses
De : jeffl (at) *nospam* cruzio.com (Jeff Liebermann)
Groupes : rec.bicycles.techDate : 04. Jan 2025, 20:06:29
Autres entêtes
Message-ID : <v5vinjtmb0d3javtd4cuc440c7qii9tp2b@4ax.com>
References : 1 2 3 4 5 6 7 8
User-Agent : ForteAgent/8.00.32.1272
On Sat, 4 Jan 2025 13:02:24 -0500, Frank Krygowski
<
frkrygow@sbcglobal.net> wrote:
On 1/3/2025 11:46 PM, Jeff Liebermann wrote:
On Thu, 2 Jan 2025 12:17:22 -0500, Frank Krygowski
<frkrygow@sbcglobal.net> wrote:
Actually, I remember sitting in a Vibrations class taught by my least
favorite professor on the day he brought in a large, demonstration-sized
Analog Computer (Remember those?) to model something we had been
calculating. To the amusement of the students, he was not able to get
the thing to work properly.
Oh yes. That brings back memories of projects that should have died
on the drawing board. In early college, I couldn't afford a real
scientific calculator (HP-35). So, I decided to build an analog
computer in a briefcase. Two 10 turn Helipots with geared dials,
discrete analog multiplier, three log amps, a large mirrored meter and
a +/-15v power supply. I couldn't find any photos. It actually
worked. However, there was some controversy over allowing me to use
it for exams instead of a slide rule. I had to demonstrate how it
functioned to the administration (several times), until they
recognized that it was actually slower than a slide rule and that
there were no stored formulas or constants. When I was finally
allowed to use it in an exam, the instructor sabotaged my efforts
creating questions that squashed the numbers into the upper end of the
log scale, which made reading the results on the meter rather
difficult. I gave up and bought a Ti SR-10, which was a mistake:
<
http://www.vintagecalculators.com/html/texas_instruments_sr-10.html>
I eventually obtained an HP-35 just in time to have the administration
temporarily ban the use of calculators during exams.
My idea wasn't to model a human body for computation purposes, although
others are probably interested in doing that. I'm thinking more of
coming up with a physical device, perhaps for weighting a tire during a
rolling drum test, so the test would more accurately reflect behavior of
tires when ridden by a human pedaling a bicycle. Maybe 75 pounds of raw
meat?
Ummm... How about a crash test dummy?
<
https://www.google.com/search?q=crash+test+dummy&udm=2>
"Cycling crash test dummy"
<
https://www.youtube.com/watch?v=5QWKWXUIPwA>
Just one problem. They're expensive. Used dummies start at about
$100,000 and can easily cost $1 million with sensors and
instrumentation.
"How Crash Test Dummies Evolved To Cost $1 Million"
<
https://www.youtube.com/watch?v=iATklZ715H8>
Maybe you should just use a reinforced mannequin?
<
https://www.google.com/search?q=human+body+mannequin&udm=2>
75 lbs of raw meat might work, but I suspect would smell rather bad.
Perhaps ballistic gel might be a suitable substitute?
<
https://www.google.com/search?q=ballistic+gel+dummy&num=10&udm=2>
My guess(tm) is about $2,500 for the dummy and underlying skeleton to
help hold it together.
Last resort would be to ask the experts:
<
https://www.humaneticsgroup.com>
-- Jeff Liebermann jeffl@cruzio.comPO Box 272 http://www.LearnByDestroying.comBen Lomond CA 95005-0272Skype: JeffLiebermann AE6KS 831-336-2558