Alt-BEAM Archive
Message #01931
To: "BEAM Mail" beam@corp.sgi.com
From: "Nigel Joyce" nigel.joyce@qr.com.au
Date: Thu, 1 Apr 1999 12:29:02 +1000
Subject: [alt-beam] The VoreBall
Hello Beamers,
I have just started with BEAM (about 6 days ago), I have buggerall
electronics knowledge but I am picking it up fast.
I have a design in mind and thought I would run it past everyone out there
and see what the response is like.
Anyone is welcome to build this, as long as you help me build it as well
with ideas, tips and problems that you experience. Basically the idea is
this:
An array of 12 or 20 solar roller or photo popper circuits arranged into a
ball. OK this is how it will work, Each circuit when it fires, would fire a
solenoid out the opposite side of the ball to the solar collectors
(photovoltaic cells). The solenoid would push against the ground pushing the
ball over onto the next side. That way, it would roll towards the light.
To build a sphere out of components (The VOREBALL), we would need either a
triangular "side" for a 20 sided sphere (bit of an oxymoron) and a
pentagonal side for a 12 sided sphere. I will talk about a 12 sided to
start off with. We have 5 photov cells in series, arranged around a
photoresistor for lightsource detection. Also with a sphere there would be
about 30 photov cells receiving light at 1 time, coincidentally the 20
sided 1 made up of 3 photov cells per side would have 30 cells in light as
well. Anyway each photovoltaic cell produces about 0.4v i think, that would
make about 2v total - 0.6v drop over the diode = 1.4v per side. Enough?
Are there higher tolerance diodes available with lower voltage drops? I
have three thoughts here. 1. Use a photopopper circuit per side with a
central supercap. (heaps of electronics) 2. Or don't use a supercap, and
allow the current to flow directly to the solenoid opposite the circuit
which is receiving the most light (if this worked (I recon) it would be a
smoother movement, more like a spherical centipede then the delayed popping
of a photopopper) 3. Or just use 12 solarroller circuits, allowing for a
haphazard firing of the solenoids, but a photovore movement because the side
receiving more light would fire more often, remembering the solenoids would
be mounted opposite the photov cells in the same circuit.
Now, for aesthetics, I see that the ball would be very tight with the only
visible parts being the photovoltaic cells and the photoresistors, and to
make it even more asthetic, have the photoresistor mounted on the top of the
solenoid from the circuit from the opposite side.
I think the 20 side concept would work better because there would be less
drive required for the solenoids.
you may also require rubber pads on each side to prevent it smashing itself
to bits.
This VoreBall Concept, is probably complicated, expensive and way out of my
league, but if anyone wants to build it, put in the time and the
maths/electronic knowledge be my guest, just acknowledge my input and help
me build 1.
It has also been suggested (by Ben Hitchcock, thanks for your help Ben,)
that I build a 4 sided tetrahedron design for simplicity but (I think) the
mechanics would not allow the ball to roll over onto the side firing the
solenoid, the angles are all wrong.
Please, any feedback would be greatly appreciated, even if it is something
like "that is bloody impossible, wake up to yourself"
Remember I have been into beam for about 6 days and I am trying to remember
high school electronics from 11 years ago.
Oh, BTW, I bought a cybug kit yesterday, wired it up on a bread board last
night and the bloody thing won't work, some problem in the 555 timer area, a
led lights up when I short across the zeiner (did I spell that right?) diode
with my finger, any ideas?
Blue Skies
---Buzz---
I didn't just kiss death, I slipped it the tongue!
nigel.joyce@usa.net
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