Alt-BEAM Archive

Message #06704



To: beam@sgiblab.sgi.com
From: Sean Rigter rigter@cafe.net
Date: Wed, 13 Oct 1999 07:16:18 -0700
Subject: [alt-beam] Re: What do I Need? - J Wilson's Gearmotors


good reply!

James Wilson wrote:

> After reading your description several times I was at first confused as=
to
> why I could get better performance out of the same motors. I will pose=
two
> questions 1> what are you using as a driver H-Bridge etc. and 2> This =
may
> be why I have had better luck, Do you think that the extra moment cause=
d by
> the off-center or ecceentric leg mount that I use could increase the
> efficiency of your bot? I beleive that this would have the effect of
> reducing the RPM and increasing the power. Not really increasing the p=
ower
> but allowing you to chanel the work into a useable form. Work is the c=
ross
> product of force and displacement so if I increase the distance the amo=
unt
> of force required to total the same amount of work is reduced. Thus a =
lever
> and a folcrum, if I use a rod 4 feet long and pin it at the 1 foot mar=
k
> then apply a load of 1 kip to each end it is easy to see that the rod w=
ill
> tip in the direction of the long side. The same ammount of force but
> different amounts of work. I do beleive with some additional tweaking =
you
> can get your walker working, but hey if you are unsatisfied just ship t=
he
> unmodified motors back and I will send you a cheque!!
>
> James :-))
> ----- Original Message -----
> From: Mike Kulesza
> To:
> Sent: Tuesday, October 12, 1999 7:38 PM
> Subject: Re: What do I Need? - J Wilson's Gearmotors
>
> >
> > I was one of the people that bought james Wilson's $5 gear motors. I
> screwed
> > in and epoxied a long screw to the center of the output gear, and ha=
d the
> > legs attached about 5 - 8 cm form the gear on a thingy that you put i=
n a
> > wall, it flips open, and you cant pull it back out. (I forgot the nam=
e,
> but
> > its two halfpipes, attached by a spring, that causes it to open and
> close).
> > The legs were pressed tightly against a screw to this device. However=
,
> this
> > walker is now scrapped, since the motors were quite weak, were to fas=
t,
> and
> > a quite heavy. I measured about 75 rpm @ 5V. The walker could not eve=
n
> lift
> > its legs. I image that the source of these motors was from some sort =
of
> > recorder...
> >
> > Oh well, this time i used hand made gear motors, made of plexiglass, =
and
> > smaller motors. They have very high torque, and are quite effective. =
As
> for
> > James Wilson's gear motors, they will probably be incorporqated into =
a
> > head...
> >
> > >From: "James Wilson"
> > >Reply-To: beam@sgiblab.sgi.com
> > >To:
> > >Subject: Re: What do I need?
> > >Date: Tue, 12 Oct 1999 18:55:30 -0400
> > >
> > >A while back I came accross some very efficient gear motors and sold=
some
> > >of
> > >them over the list at 5$ cdn each I thought that it was a great deal.
> Many
> > >of you complained b/c they did not have an out put shaft, so much fo=
r
> > >ingenuity!. I have recently had some time to get back into beam and
> built
> > >a
> > >walker out of them, my mechanics need a little work but one thing to
> > >remember is that not a single walker design calls for 360=B0 of rota=
tion
> for
> > >a
> > >leg or leg pair. The largest one could possibly utilize is a swing =
of
> 90=B0.
> > >But that too is impractical. The optimum is, imho, between 30=B0 an=
d 60=B0,
> > >which my motors will easily accomodate. They turn nearly 180=B0 wit=
h my
> > >current setup, I drilled a hole in the out put gear and screwed the =
leggs
> > >to
> > >it. These have built in mechanical stops and heaps and heaps of tor=
que.
> > >The most recent mucking about I have done is with Chiu's Two Motor W=
alker
> > >and I used 5M resistors in my microcore instead of 1.5M and an LS dr=
iver.
> > >The walker woked really well, almost to much power! But like I said=
my
> > >mechanics need some work cause the darn thing gets it leggs stuck an=
d
> then
> > >just flips it self over and goes into saturation but as with all bea=
m
> stuff
> > >I will tweak and triumph. Last night I tried them with the beam ant
> > >circuit
> > >using an acx for a driver works great! So for those out there that =
are
> > >willing to tweak I can get more motors the price is the same just le=
t me
> > >know!
> > >
> > >James :-))
> > >----- Original Message -----
> > >From: Senior
> > >To:
> > >Sent: Monday, October 11, 1999 10:59 PM
> > >Subject: Re: What do I need?
> > >
> > >
> > > > Well, you'll have to do a bit of studying and decision making.
> > > > Some comments:
> > > > 1 - It's hard to get 2 motor walkers to do much, like turning, bu=
t
> > > > reversing is no problem, and you could most likely tweak it to ge=
t it
> to
> > > > turn.
> > > > 2 - It aint gonna be cheap. Motors that walkers use are extremely=
hard
> > > > to come by and especially when their cheap. You could use servos,
> which
> > > > are 10 bux a peice, but that right there is 20 dollars, which is =
out
> of
> > > > my budget.
> > > >
> > > > Uh... that's about it.
> > > > You could use the traditional walker from:
> > > > http://www.golden.net/~amiller/
> > > >
> > > > Or the bicore walker thing from Ian's site:
> > > > http://www.beam-online.com (it's in there somewhere...)
> > > >
> > > > And check out the FAQ:
> > > > http://people.ne.mediaone.net/bushbo/beam/FAQ.html
> > > >
> > > > After reading each of those sites carefully, you will know how to
> build
> > > > a walker! Ta da!
> > > >
> > > > Happy Beaming,
> > > > Kyle
> > > >
> > > > Chris wrote:
> > > > >
> > > > > Ok, Here's my deal. Since I'm only 15 and do not have a job I =
want
> to
> > >get the most bang for my buck. I need to know what I need to make a=
2
> > >motor
> > >walker with 4 touch sensors, 2 photodiode eyes, that can go backward=
s,
> > >right, left, forward, is nocturnal. By nocturnal I mean uses a sola=
r
> cell
> > >in daytime to charge its batteries when it bicore is off, then at ni=
ght
> it
> > >turns itself on. So I need to know what I need because I don't want=
to
> > >have
> > >to pay shipping and handling twice (or more). And I need a site tha=
t
> tells
> > >me how to hook these things up.
> > > > >
> > > > > I'm new to all of this BEAM stuff, but I pick things up fairly
> easily.
> > > > >
> > > > > Win a LAPTOP Computer and get your FREE E-mail Account at
> > >http://mail.chek.com
> > >
> >
> > ______________________________________________________
> >


6705 Wed, 13 Oct 1999 09:45:04 -0500 [alt-beam] Re: Was: What do I Need? beam@sgiblab.sgi.com Richard Piotter Haha! Seriously, If you can find them at a dump or ask the utility
company what is done with damaged ones... Might be worth while. I've
never asked, and I don't know if they'd be cooperative. Those things may
be something that they refurbish when damaged, but if you can get them,
VERY cool!!! I'll be looking, and I'll ask the teacher how the lab
accuired so many. DO NOT RIP OFF OF HOUSES! :)

John Leo Zimmer wrote:
>
> ----- Original Message -----
> From: Richard Piotter
> To:
> Sent: Tuesday, October 12, 1999 7:47 PM
> Subject: Re: What do I Need? - J Wilson's Gearmotors
>
> | SEEK OUT UTILITY POWER METERS!!! (like the
> | ones that are on the side of your house or at the electric pole or in
> | your basement).
> |
>
> BUT be careful when you pull it off the house...
> dangerous voltage there !!!

--


Richard Piotter
richfile@rconnect.com

The Richfiles Robotics & TI web page:
http://richfiles.calc.org

For the BEAM Robotics list:
BEAM Robotics Tek FAQ
http://people.ne.mediaone.net/bushbo/beam/FAQ.html



6706 Wed, 13 Oct 1999 10:11:51 -0500 [alt-beam] Phototransistor switch "Beam@Sgiblab. Sgi. Com" "Phillip A. Ryals" Hi everyone, I have an idea that I was hoping someone might be able to help
me with. I work with fax machines, and I started noticing some of the
switches that are used inside them.

They use a Photodiode arrangement similar to a mouse. Basically an emitter
and a detector.. when the path is interrupted, etc.

I have a great supply of a switch harness from a particular fax that has a
six-wire plug, and two of the "switches" connected to it with about 6 inches
or wire.

My question, can we use this kinda thing for BEAM? I really want to use
these switches for touch sensors - they have a small finger-like projection
that's spring loaded. I'm just trying to figure out how you could implement
them into a traditional BEAM circuit.

btw, forgive me, my cicuit design skills are pretty raw. Hence, I need your
help.


Thanks tons,
par


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