Alt-BEAM Archive

Message #11537



To: beam@sgiblab.sgi.com
From: BUDSCOTT@aol.com
Date: Wed, 8 Mar 2000 19:36:59 EST
Subject: [alt-beam] Re: Walkers


>When designing a 2 motor walker, how do you tell the bicore where the leg
>is?
>is this self governing or is there need for stops and sensors for this?

No, the bicore simply times the occilations of the Nv. + then - then + then
-, see. as for stops and/or sensors, sensors are too complex, if its your
first walker, like with mine, don't try to be to complicated, it screws
things up. I used rubber bands attached to the body and legs to keep the legs
from straying away, don't use stops, it can screw up a perfectly good motor,
rubber bands won't stop the motor but help the motor when its moving back,
thats why i like them.

>If i choose to build a wheeled unit whould that not mean that only one motor
>would be opperating at any one time?
>
>or on wheeled units do you setup independent bicores to controll each motor?

Depends on light, bright light both motors, dull light one motor. or so i
think. somebody pointed me to a web page that had a nice little BEAMant
description and schematic, but it escapes me at the time. Good luck!

-Spencer



11538 Wed, 8 Mar 2000 19:42:48 EST [alt-beam] Re: thrust and lift (was: Turning the walker) beam@sgiblab.sgi.com BUDSCOTT@aol.com I think what might work would be putting photoresitors on the timing
resistors, this would throw it off enough to turn it, hopefully. I've got
return bands to keep the motors in place but that isn't too hard to
comprimize. i've got one of my timing resistor a 1M with a 1M pot so i can
fine tune the gait (thats the correct term isn't it?) anyway i've got some
really good ideas from people on what to do, i think i'll make some kind of
socket so i can remove the "eyes", i might use the mini phono 1/16 in plugs
and put the eyes on the end, there is a way i can make the resitors connect
and unconnect that way. Experimental, thats the word!

-Spencer



11539 Wed, 08 Mar 2000 17:07:05 -0800 [alt-beam] Re: Diodes in microcores beam@sgiblab.sgi.com Bruce Robinson Flaming Headphones wrote:
>
> Hello all,
> I'm just looking at a walker schematic, actually the one from
> Chiu's site at: http://www.geocities.com/SouthBeach/6897/ucore.jpg
> and I'm just wondering what the purpose of the diode is between
> the #2 and #3 pins on the 74HC14? Do all circuits like this need
> one(diode)?

Hi, Mike. That inverter in the lower left is the (now) old fashioned PNC
that extinguishes the extra pulse you get when the microcore starts up.
You need the diode to isolate the PNC after it times out.

For a 4-Nv microcore, you can accomplish the same thing much easier with
a couple of diodes (and no PNC). Wilf came up with this a while back,
and you should find the circuit at the Beam Heretics site.

Bruce



11540 Wed, 8 Mar 2000 17:10:24 -0500 [alt-beam] Re: Tower hobbies servo "Jim Taylor"


> All I'm saying is:
> Tower hobbies servo Dose not = Tower hobbies servo Dose not =
> Tower hobbies servo Dose not = Tower hobbies servo Dose not =
> Tower hobbies servo...
>
> They are very inconsistent... Just like rat shak... I have flown some
> (throttle only) and had troubles... I know others that swear by them and
> some that swear AT them...

This was probably Pre system 3000. I used to use alot of "tower like"
servos in some of my hobby products, and they are inconsistent. However
Futaba is now producing their system 3000 servos....good buy



James Taylor


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