Alt-BEAM Archive

Message #06985



To: beam@sgiblab.sgi.com
From: Bruce Robinson Bruce_Robinson@telus.net
Date: Thu, 21 Oct 1999 23:30:40 -0700
Subject: [alt-beam] Re: Bicores aren't the only thing that are imbalanced...


"John A. deVries II" wrote:
>
> Methinks that instead of all of the hacks
> that we've accumulated (particularly the
> mechanical ones) that a simple, true method
> for achieving "tweaking" might be an interesting
> electronic design topic.

Hacks? Mechanical ones?

Hey, John, try this. Hold your arm up in front of you, parallel to the
ground, palm up. Now, keeping your upper arm level, bend the elbow so
your hand moves toward your face. Make a fist. Now snap your arm
straight, as fast and hard as you can.

One of two things happened. If you haven't done this before, you
probably hyper-extended your elbow. In other words, you extended your
arm to its maximum limit, at which point it ran into a mechanical stop!
Yup, there's an extension of your ulna (one of two bones in the
fore-arm) that makes contact with your humerus (bone in the upper arm)
when your arm is fully extended. A mechanical stop.

If you HAVE done this before (ouch), when you repeated the exercise this
time, your biceps probably tightened just before the joint was fully
extended, to prevent sudden contact between the bones. Learned feedback!
Like a pot' or a switch that senses when a leg has reached its limit.

Of course, that contraction of your biceps didn't stop the motion
instantly. It brought it to a quick (and probably smooth) stop, most
likely with a tiny bit of bounce at the end. Like a spring.

Nature uses all these "hacks". Mechanical stops, limit sensors, and
springs. I just happens to "build" them a little more elegantly then
some of our initial efforts. And nature also tries to prevent mechanical
damage to the structure, via such things as pain sensors and learned
responses.

Sorry, I guess I'm sensitive to mechanical criticsm .

Bruce



6986 Fri, 22 Oct 1999 08:56:57 +0200 Re: Tilden on PBS beam@sgiblab.sgi.com Sean Rigter [mailto:rigter@cafe.net]
Well Chris,

a little less porno and a bit more geography would help. A person from
Holland (Nederland to be precise) is a Dutchman and is definitely not a
German. Different language and culture my friend.

Truth is, I'm a Dutchman too!

wilf

Chris wrote:

> Why does every one think Germans are so advanced at engineering? Das BEAM
stuffe ist toll! thats some of my limited german vocab... How come I never
get to see tilden on PBS, I got to stop watching the porno at night.
Someone tell me next time its on.
>
> On Wed, 20 Oct 1999 22:39:30 +0200 Arno Jansen
wrote:
> >That's actually what I meant, but I wanted it to say a bit more nicely.
And
> >indeed, I DO love the tech, I don't have as much fun in building, well
> >because you know.... the parts thing...hehe But eh! There are a few
Beaming
> >Dutchmen which have been able to build a few bots, so why shouldn't be
able
> >to do it....right???? Yeah right.
> >
> >seeya!
> >Arno
> >
> >-----Original Message-----
> >From: owner-beam@sgiblab.sgi.com [mailto:owner-beam@sgiblab.sgi.com]On
> >Behalf Of JVernonM@aol.com
> >Sent: woensdag 20 oktober 1999 20:50
> >To: beam@sgiblab.sgi.com
> >Subject: Re: Tilden on PBS
> >
> >
> >In a message dated 10/20/99 10:36:53 AM Eastern Daylight Time,
> >arno.jansen@superconsult.nl writes:
> >
> >> But if Tilden broke through something, he wouldn't let us know
> >> until some very thorough research has been done. Or am I wrong on
this?
> >>
> >Actually, he wouldn't let us know at all. We're just the people who love
the
> >tech and love to build. He doesn't divulge any info to the likes of us.
He
> >waits until he can address the techniques to someone very important in
the
> >scientific community. Like a producer of documentaries for the Discovery
> >channel.
> >Sorry, but this string has dredged up some sore spots that just get more
> >putrid.
> >
> >



6987 Friday, 22 October 1999 1:28 Re: [alt-beam] Re: Tilden on PBS beam@sgiblab.sgi.com Ian Bernstein
>Hi
>
>>Thats strange, I know of only 3 people who have built turbots, Richard,
MWT,
>>and Dave.
>And Paul Beckingham who has his tubot very well documented on his web
>site @ http://www.beckingham.com I think.
>
>Laterz
>
>--------
>There is only one true "SyNeT"
>BEAM Online - http://www.beam-online.com
>
>I didn't fight my way to the top of the food chain to be a vegetarian.
>

Home