Alt-BEAM Archive
Message #10253
To: beam@sgiblab.sgi.com
From: Bruce Robinson [mailto:Bruce_Robinson@telus.net]
Date: Tue, 15 Feb 2000 14:54:49 -0600
Subject: Re: ....still more questions, thanks.....
"Scolman,Jim" wrote:
>
> ... the solarpopper style robots....the two motor ones,
> why do they run on just the tubing covered motor shafts? ...
> ... is it because of the mechinical leverage envolved, a
> large wheel has a long lever arm, etc.
Exactly.
You can, however, use an idler wheel between the motor shaft and the
ground. This does not change the overall mechanical ratio, but it does
provide you with a wheel that can roll over cracks and uneven surfaces.
See attached.
Typically, the motors are mounted on the robot frame with the shafts
parallel to the ground. The wheels are mounted on small pivot arms, so
the motor shafts are pressing down on top of them. This is quite
different from mounting the wheels ON the motor shafts.
Steve Bolt has used this arrangement on a number of his robots. Look at
http://www.xs4all.nl/~sbolt/Other/suneater.html
Regards,
Bruce
10254 Tue, 15 Feb 2000 16:11:01 EST [alt-beam] Re: The jump-noid beam@sgiblab.sgi.com BUDSCOTT@aol.com thought i'd clarify my last message, it was kinda garbly, i did it while i
was in study hall, hehe! The legs on the jnoid would be stationary, they
won't be pushed or pulled. the legs would mount the solenoid so that the
solenoids would be out in front of the bot instead of in back pushing. too
bad i couldn't really sketch this out. umm.
/\
/ \ <------these five segments are the legs
=== \
/ <---this segment is the solenoid at a 45 degree angle
^--- the "="'s represent the potentiometer
does this clarify that. yeah i agree that pulling those legs would take too
much current to be anywhere near effecient. Plus this would, hopefully, pop
the front end up at least a few millimeters, enough to make it a bit of a
climber! i'll try and get pictures posted when i finish! thx for the insight
guys your a lot of help!! Keep on BEAMin!
-Spencer
10255 Tue, 15 Feb 2000 22:25:11 +0100 [alt-beam] Re: Solar cell Q "henk verbeek" thats right, you've got it
----- Oorspronkelijk bericht -----
Van: William Cox
Aan:
Verzonden: dinsdag 15 februari 2000 21:32
Onderwerp: Re: Solar cell Q
> So a cap can store MORE current than the cell supplies at one time and NO
> MORE voltage than the cell can supply at one time? Is that it?
> -William
>
> ----- Original Message -----
> From: Sathe Dilip
> To:
> Sent: Tuesday, February 15, 2000 10:28 AM
> Subject: Re: Solar cell Q
>
>
> > The capacitor we connect in parallel with the solar cell acts like a
> > current storage tank. You save enough current to last you for a small
> > burst of motor (run) power. The level of current stored in the tank is
> > indicated by the voltage on the capacitor. How much current you can
> > store is decided by the size/value/capacity of the capacitor.
> >
> > I don't know about the American curriculum but we used to have math
> > problems in school about a tank with a faucet filling it & another
> > emptying it. If you have done those, you will understand the above
> > analogy even better.
> >
> > Dilip
> > -------------------------
> >
> > William Cox wrote:
> > >
> > > Q: All the solar cells in Solarbotics catalog have a small current
> rating, I
> > > mean, that the current they supply is smaller than the motors draw
(30 -
> > > 45ma). How does this work? I've got the MPJA motors, and someone said
> that
> > > they draw about 45ma, what type of solar panel should I use? I'm using
a
> > > FLED, so I guess I'd need something with >2.4 or so volts. What about
> > > current? Right?
> > > -William
> > >
> > > ____________________________
> > > http://robot-central.webjump.com/
> > > Robotics books, projects, resources,
> > > links, news, and more!
> >
> > --
> > ----------------------------------------------------------------------
> > The early bird may get the worm, but the second mouse gets the cheese.
> > ----------------------------------------------------------------------
> >
>
>
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