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BEAM Walking Robot

I've gone through the Junkbots book and built a few of the cool robots Hrynkiw & Tilden describe in it, but one of the designs I was especially interest in was the walking robot.

First, the video I put together describing the robot and a bit about the building process.

YouTube Video




Here's a scrapbook version of the building process...


The basis for the robot's brain - a 74HC240 octal inverting buffer.

Some configurations of inverters. Perhaps not how these inverting buffers were intended to be used, but they yield some very interesting behavior for a robot that mimics life.

Two pairs of these "bicore" inverter loops make delayed pulse signals. Great for driving little DC motors that have legs attached.



The 74AC240 variant of the octal inverting buffer chips can produce enough current to drive small DC motors directly (particularly if you double or triple up the outputs). The HC version which I had, can actually come close, but because I didn't want to double up outputs (I only wanted to use one chip for the robot brain) I built a couple of separate "h-bridge" motor drivers. Six transistors, no protection against both inputs being activated simultaneously (which would fry the transistors), but we can generally get away without the protection since the inverter bicores by their nature only have one signal high at a time.


Modifying a little hobby servo motor - basically disconnecting the leads from the tiny PCM processor board inside and adding separate leads so that I can drive the gear motor directly by applying voltage of + or - polarity across the two motor leads. It's just a cheap way to make to DC gear motors.


I'll try to flesh out this page in the future. The video at the top covers most everything, however.



If you'd like to help in my robot  building and videos about electronics, you can donate at PayPal!