Walker Number 5

My First One
Two Motor WalkerSchematic
This one has a movie1.37MB MPG Movie, 320x200 resolution, 15 seconds..
Nihon Mini Motor Bug
The Gear SetGear Modifying Instructions.
Bridge Head

Symet Page
Turbot Page1.37MB MPG file, first one.1.37MB MPG file, second one.
Biggie Page
Slider Pagewhine-whine-whine-WHINE-WAV file, 76K.
PIC-16LF84 chip, emulates a microcore.Schematic - JPEG image 925 x 683 pixels.Source file for GP16LF84.Hex File for programming into PIC-16LF84-04/P


About 1 week ago, I was at ROSS (dress for less) and found a Discovery Channel (LearningCurve) Robotix kit. It was the CyberArm one. It has two gearmotors in it that run on 3-volts-DC (two AA battery packs for each motor). One gearmotor is what they call "high-speed" and the other gearmotor is what they call "high-power". I bought this kit on sale (dumping?) for $10.00US. The battery cases allow forward and reverse motor rotations with their built-in switch. I took it home and put it together as a "walker".

My son-in-law and his two boys watched in gleeful anticipation of it walking. I could get it to walk but only by manually running each motor (and rotation, tricky) separately. Since then my son-in-law found another same box for $8.00US.

Since then, I have found the battery pack and "high-speed" gearmotors combination at etoys.com for $4.95 each. I bought four of them. (They are now out of business, bummer.)

The price for the "high-power" motor is $14.95. It comes with the battery pack and also an extension cable.

Robotix did send to me a catalog of prices for replacement parts, and the "high-power" (low-speed) gearmotor (#25) is $9 and the "high-speed" gearmotor (#25) is $10.00.

Click for larger image.
Click for larger image.
Click for larger image.
I have put it together so that it now walks. I put the low-speed motor up front for the back/forth front legs and the high-speed motor, on the 45 degree tilting forward, rear lifting legs. I used 74AC14 PNC microcore (2M & 0.22uF) and 74AC240 motor driver. Since I use 6V alkaline batteries, I put a dropping diode in series with the +battery lead to get the chip voltage down to about 5.5 volts. The two extra 74AC14 gates I hooked up to Nv 1 & 3 outputs for LED's later. This could give blinking "eyes" as it runs.

These motors are NOT hi-efficiency types, in my opinion, even though they do run on 3volts (two AA batteries). They do need an H-Bridge or doubled 74ACxxx drivers before they will run. I tested each of the four motors that I got from etoys.com and one of them goes faster in one direction than the other direction. I opened one of them, the motor is large, gears are all plastic. Kinda reminds me of the insides of a servo motor. It seems to have some kind of "slip-clutch" that 'clicks' when it comes to an unmoveable limit.

Click for really large 1297 x 845, a 19K_GIF
And here's the schematic that I used.

Paul T. Barton

This page updated: February/27/2002

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