Alt-BEAM Archive

Message #11073



To: beam@sgiblab.sgi.com
From: "Timothy Flytch" flytch@hotmail.com
Date: Mon, 28 Feb 2000 22:49:50 PST
Subject: [alt-beam] Re: building caps?


>
>crazy idea:
>
>do you think it would be possible to BUILD a capacitor to power the
>bots?
>
>niels walkau
>
Sure... But the question would be why??? if you just want to experiment...
Then I agree with nike... Just do it!! try aluminium foil and plastic bag
material or wax paper... seems that most caps use mylar... but almost
anything will work... even paper (as long as it is not raining or high
humidity)
You will not get a more efficient cap then you can buy but you will learn a
lot about caps just doing it... the only real critical part is making sure
the plates don't short out... but that is not a dangerous with BEAM bots
(low voltage/amperage)...
Remember... this is an exercise in fun... and expanding the mind is fun in
my book :)

Timothy...
______________________________________________________



11074 Mon, 28 Feb 2000 22:51:19 -0700 [alt-beam] Lockin up Beam List Senior Hey everyone
I've breadboarded stupid SE's many times, I've made many, never had any
problems untill now! I'm trying to make a symet, and the darn thing just
buzzes, the most common sympton of the famous 'lock up'. I've replaced
the standard 2.2k resistor with 1.1k, still the same. I'm using a nromal
cassete motor from mabuchi - 15ma draw..., and an array of 8 capacitors
totaling 5700 uF. Is the resistor too small now?

Thanks,
Kyle



11075 Tue, 29 Feb 2000 00:50:58 -0600 [alt-beam] Re: mini walker beam@sgiblab.sgi.com Richard Piotter
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Is there a way to focus the magnetic field to a smaller area, yet not be
attracted to a magnet when no power is applied. I assume that's what
iron cores are for, but the tiny magnets I'm using are very powerful,
and they stick to the iron cores. is there a special type of core I
should use, or can I use one of those ferite cores? Can ferite cores be
cut? I know they chip. The magnets are 1/4 inch diameter,

Absolute worst case, I'll mount coils in front and back of the robot
instead of on the inner side of it. Might not look as nice, or be as
compact, but if it makes it work.

I've completed a frame for my robot, and it's unbelievably nice. all
joints are very low friction. I used brass screws and guitar wire. It
all solders together nicely. As joints, I put the screws half way in,
and then make the joints. I highly recomend it if you need a small joint
that's easy to work with.

I've essentialy put together a tiny 1.5 inch long walker that is driven
by coils like on a magbot. I'm still deciding what type of driver to
use, but I want it to be a single chip device. Solar power, or at least
solar assist is desirable. Because it has no motors or electricaly
active joints, there is practicly nothing to wear out! I was going to
fully complete the bot before announcing it, but I'd like to hear
people's advice on making it as efficient as possible. I want this bot
to be definitely worth while.

I'm sending a picture to show how small it is. All I need are 2 "major
henry" strenth coils. I'm going to see what kind of speaker wire is
avaliable localy and wind my own coil. I'll have to dig up my text books
from last year. Figure out the best possible coil configuration.

Oh, here's a question aimed for Ian. Does your almost complete walker
circuit work with inductive coils? I'm assuming it does, since motors
use inductive coils. Unless I'm told otherwise, I'm working on the
assumption that it will drive inductive coils, and will be able to
reverse the polarity when the switch is hit.

I'd call the thing Walkman Jr., but I already took the name! I may drop
the Jr. off my original, my first bot, inspired by Tilden's Walkman,
since I always forget it anyway. Then the REAL junior can have the Jr.
label! :)

What's everyone think of this?


Dave Hrynkiw wrote:
>
> At 07:53 PM 2/28/00 , Richard Piotter wrote:
> >Would one of those major henry coils put more kick wound as it is, or if
> >it were wound into a more compact form?
>
> I designed the CMH (major henry coil) to the specs provided by Mark Tilden.
> From what I got from him, a large diameter coil with as small a center
> ole as possible was the best way to get a large projected EM field. He said
> ideally, a single-wire thickness coil as large a diameter as possible would
> be ideal.
>
> >The robot I'm woking on needs the kick those major henry coils put out,
> >but the space is limiting. It'd be much easier to have a could shaped
> >like the following:
>
> Why not? I can't provide you with the calculations (I have
> them...someplace...), but I imagine you need as many turns as possible with
> as low resistance you can get away with. There's a balancing act there
> (thinner wire=more turns, but more resistance).
>
> >Is there anything special to winding coils? would the major henry coil
> >have as much kick as it curently does if it were rewound like the lower
> >picture?
>
> Miller has had success using plastic sewing bobbins as cores for coils, and
> "magnet" wire is pretty inexpensive. Look at surplus sources. Chuck that
> coil into a dremel, and zoooooom! One coil!
>
> Good luck,
> 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

--


Richard Piotter The Richfiles Robotics & TI web page:
richfile@rconnect.com http://richfiles.calc.org

-- Make Money by Simply Surfing the Net or responding to E-Mail!!!
-- Click below!!!

http://www.alladvantage.com/go.asp?refid=ATL147
http://www.spedia.net/cgi-bin/dir/tz.cgi?run=show_svc&fl=8&vid=329630

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x-mac-creator="474B4F4E";

Attachment: MicroWalker.jpg

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11076 Tue, 29 Feb 2000 00:45:44 EST [alt-beam] update beam@corp.sgi.com Bumper314@aol.com Hello,
If anyone is interested I have added a few pictures of the bots I have
built lately. they are HUGE photos And I just didnt care about formatting so
the page looks like crap.
http://members.xoom.com/Bumper314/update/update.html
if the photos don't load then someone please just contact me privately. I'm
sure the whole list doesnt care about it
Steve



11077 Mon, 28 Feb 2000 22:55:07 -0700 [alt-beam] Re: mini walker beam@sgiblab.sgi.com Dave Hrynkiw At 07:53 PM 2/28/00 , Richard Piotter wrote:
>Would one of those major henry coils put more kick wound as it is, or if
>it were wound into a more compact form?

I designed the CMH (major henry coil) to the specs provided by Mark Tilden.
From what I got from him, a large diameter coil with as small a center
ole as possible was the best way to get a large projected EM field. He said
ideally, a single-wire thickness coil as large a diameter as possible would
be ideal.


>The robot I'm woking on needs the kick those major henry coils put out,
>but the space is limiting. It'd be much easier to have a could shaped
>like the following:

Why not? I can't provide you with the calculations (I have
them...someplace...), but I imagine you need as many turns as possible with
as low resistance you can get away with. There's a balancing act there
(thinner wire=more turns, but more resistance).


>Is there anything special to winding coils? would the major henry coil
>have as much kick as it curently does if it were rewound like the lower
>picture?

Miller has had success using plastic sewing bobbins as cores for coils, and
"magnet" wire is pretty inexpensive. Look at surplus sources. Chuck that
coil into a dremel, and zoooooom! One coil!

Good luck,
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



11078 Mon, 28 Feb 2000 23:13:36 -0800 [alt-beam] Re: Bot Video Relocated "Dane Gardner"
content-transfer-encoding: 7bit

Works great...and looks great too. It's not entirely to slow...but I have a cable modem.

I never knew you could hack servos and get results like that... That thing really gets up and
moves... I guess I should have tried them...Oh well...next project.

Dane



From:SG

ok folks, couldn't get the Angelfire site to work right, but Elmo has
graciously offered to host the link. It is in Australia, so it'll be a bit
slower download for us wallabies in the west.
but hey! its free! so i'm not complainin!
see the acadamy award winning footage at:
http://beam.tolmie.net/download.htm

let me know if what you think
-Sparky




content-transfer-encoding: quoted-printable



>
Wor=
ks =

great...and looks great too.  It's not entirely to slow...but I have a=
=

cable modem.

I never knew you could hack servos and get results like=
=

that... That thing really gets up and moves... I guess I should have tried =

them...Oh well...next project.

Dane



size=3D4>

From:SG

ok folks,  couldn't get the&nbs=
p; =

Angelfire site to work right,  but Elmo has
graciously offered to h=
ost =

the link. It is in Australia, so it'll be a bit
slower download for us =

wallabies in the west.
but hey!  its free!  so i'm not =

complainin!
see the acadamy award winning footage at:

href=3D"http://beam.tolmie.net/download.htm" =

target=3D_blank>http://beam.tolmie.net/download.htm

let me know =
if what =

you think
-Sparky





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