Alt-BEAM Archive
Message #10504
To: beam@sgiblab.sgi.com
From: Dave Hrynkiw dave@solarbotics.com
Date: Sun, 20 Feb 2000 12:25:42 -0700
Subject: [alt-beam] Re: solarbotics pager mtr+fan
At 07:49 AM 2/20/2000 , Bob Shannon wrote:
>Ahhh, can you list production aircraft with counter-rotating props?
>
>And how many more can you lise with both props rotating in the same
>direction?
One jumps to my mind: the V-22 OSPREY tilt-rotor. Oh, and the Piper
Seminole (still in production? Dunno...) And (outside the requested spec)
originally, the Wright Flyer, and more notably in WW2, the P-38 Lightning.
Granted, it is NOT very prevalent because the added expense of a 2nd
gearbox and 2nd type of propeller. BUT, if you look at the boating
industry, there are many twin-engine designs using counter-rotating
propellers, for the same reason - torque steer cancellation.
Regards,
Dave
---------------------------------------------------------------
"Um, no - that's H,R,Y,N,K,I,W. No, not K,I,U,U, K,I,_W_. Yes,
that's right. Yes, I know it looks like "HOCKYRINK." Yup, only
2 vowels. Pronounciation? _SMITH_".
http://www.solarbotics.com
10505 Sun, 20 Feb 2000 14:35:03 -0500 [alt-beam] Re: Where's the FAQ? beam@sgiblab.sgi.com "FCO Enr."
Greetings,
You know I had the same question a few months ago and I
got the same answers, that the site was down and I had to wait until
the end of the month. Now there's something real odd about the fact
so many people on this list obviously know about The Beam Heretics
web site, which so happens to host an unofficial mirror to Bushbo's
Tek FAQ. I just thought that was abit odd that no one ever mentions
it. I guess it must really be regarded as taboo or something.
The Beam Heretics
Tons of great info and links as well as an unofficial mirror to
the BEAM TEK FAQ for when you absolutely need the info
and can't wait for the end of the month :)
http://www.serve.com/heretics/
Andy
fco@total.net
>If you are refering to the links to Bushbo's site, there seems to be an
>automatic cutout with his ISP that blocks access whenever the monthly
>traffic exceeds a maximum. So late in the month, it will appear that the
>link is broken. Wait until the first of the month, and you'll find them
>working again.
>
>Regards,
>Bruce
10506 Sun, 20 Feb 2000 14:30:43 EST [alt-beam] Re: newbie electronics questions beam@sgiblab.sgi.com BUDSCOTT@aol.com >i have some small 3v motors kicking around (i don't know what the
>current draw is)
To answer your question about motors, to find out the current draw of the one
3v you can use a multimeter with an amp reading. hook the motor up to a
battery using the meter to complete the circut, that gives you an accurate
reading.
>what rating of capacitor should i be using? i am not sure of the
>significace of the farad rating on the capacitor. i understand the need
>for the voltage rating on it.
a solar engine is a circut designed to drive a motor that requires quite a
few milliamps, with a small solar panel that puts out about 1 mA. the purpose
of the cap is to store up enought current to create a spike of amps that will
spin the motor. so the farad rating on the cap is what gives you current, the
higher the rating, the longer your SE will charge and more current is
supplied, the lower the rating the less time to charge and a lesser amount of
current, so it depends on your style, you'll build a few before you find out
whether your a quick charger or a long charger. so 4700uF is perfect for the
first time round, just remember its better to over drive a motor that to
under drive it! Good luck!
-Spencer
10507 Sun, 20 Feb 2000 14:32:47 EST [alt-beam] Re: Where's the FAQ? beam@sgiblab.sgi.com BUDSCOTT@aol.com so thats why i always get that wierd message whenever i go to beam tek, i've
only been able to visit that site once, thats odd.
-Spencer
10508 Sun, 20 Feb 2000 14:42:06 EST [alt-beam] Re: BEAM: Tendency toward miniaturization beam@sgiblab.sgi.com BUDSCOTT@aol.com that is kinda wierd to think of. i'm only 16 and probably will be building
electronic devices the rest of my life. can't imagine what kind of strange
and bizarre things BEAM might turn to? humanoid walkers, flying helicopters,
things to attack your neighbors dog. crazy! i'll be happy just as long as
mine work!
back on topic, i find that sometimes miniturazation tends to decomplicate the
project. none of my small bots are very complex, while when i made my larger
photovore, it was a cinch to put on the bells and wistles, bigger solar
panels, and touch sensors. perhaps its going back to that complexity issue
with CPU controlled bots. where as the CPU bots cant find enough processing
power, BEAM bots can't find efficient enough higher voltage circutry, or just
flat out big enough motors with enough torque to lift themselves up. maybe
gas powered bots is the next step. hehe, put photo diodes in place of
headlights on my civic, hook it up to the power steering unit, wait, no, i'd
probably kill myself or destroy somthing expensive nevermind. i'll just stick
to the little bastards.
-Spencer
10509 Sun, 20 Feb 2000 14:51:57 -0500 [alt-beam] Re: newbie electronics questions alt-beam@egroups.com, "beam@sgiblab.sgi.com" David Simmons
Michael Hirtle wrote:
> Hi.
> You will need a solar cell that provides more current then 1.4mA
> it should at least be 8mA.
> for the capacitor it should be anywhere from 1000uF to 1F depending on what
> you want to build.
> 4700uF is the most common capacitor for solar engine use.
> the capacitor should be 6.3V that is the lowest voltage you can find except
> for a 0.33F cap which is 2.5V and the 1F caps can get as low as 2.5V also.
> You can find solar cells at www.solarbotics.com or www.adaptobotics.com
There is a far wider range of caps than you might think, currently in my sons
little stock pile he has 0.047F at 5.5v, 0.022F at 5.5v, and we are looking
for a supplier for a long list of other high range caps that currently we have
only been able to find by salvage. Try taking a close look at motion
detectors, and wireless alarm horns. Most have great caps for beam.
Regards,
Dave
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