BEAM Robotics- based on Nervous Network Technology

Dradis is a 5 motor walker based on Mark Tilden's original Vbug 1.5 Walkman. Well, sort of anyways.

The original Walkman was quite an amazing machine, a "capable quadruped having 1.25 DOF per leg". Walkmans showed a considerable propensity for exploration, however despite the papers and studies on its abilities,to me, they remained a mysteryyyyyyyyyyyyyyyyyyyyy.
So, wanting to find out what they were, I decided to build my own version of Walkman using Tilden's handwritten notes on the machine. Special thanks goes to Harold Ilano, through his correspondence via email I was able to learn some tips and give some ideas for improvement on Tilden's design.
I also want to say that TILDEN DIDN'T GET THE ESCAP MU915L MOTORS from SONY WALKMAN WMD6Cs. I have one of these machines, and They DO NOT use those motors. In fact, the only thing which Tilden(that I can see) used is the front fascia panel from the WMD6C (metal panel which says "WALKMAN") as Vbug 1.5's cover. It is unclear what electronics components were used as well.

Vbug 1.5 schematic Dradis Schematic Dradis Planform
vbug1_5.gif .JPG .JPG

Building this robot presented its own unique set of challenges. But it was a worthwhile endeavour, it is a fun toy to play with and it has taught me much about electronics and Nv tech.
Dradis exhibits all of walkman's features, including the crabwalk!
Walkman exhibits "aggressive phototropism", the eyes being connected to the Enable pins of the leg motor driver AC240. While this is an effective way to turn the robot(the eyes effectively shut off one side of the robot), when placed in bright Caribbean sunlight, the robot won't move. The resistors had to be considerably high for outdoors operation. This means that even brighter light must be used to attract the robot.


Dradis was built with what ever could be found at the time. As usual, I try not to purchase things.


  • Nokia N810 case [my friends cat broke it]

  • Brass terminal blocks

  • Solarbotics Leg mounting pads [My favourite SB item]

  • Solarbotics Gumby wire [legs]

  • Rubber Antenna booties

  • M3 nuts and bolts

  • Fine brass wire (tactile sensors)

  • Male DC barrel plugs (tactile sensors)

  • Generic Breadboard with IC foil pattern and double sided copper clad PCB

  • 5 GWS mini servos (removed electronics only)

  • 3.6V Li-Po from smashed iPod Mini

  • Hi-end IDE cable [connecting wires]


  • Crab-walking, hard turning, reversing, turn and reverse, phototaxis


  dimension /mm
length 180
width 72.6->160
height 60





Well here are some pictures of the robot. All you need to do is to click on the picture and a pop-up window will load showing it to you! These are very hi resolution phots, I think 2048 x 1537. Enjoy and there are many more to come.

Dradis Photographs
Set52_04.jpg Set52_06.jpg Set52_07.jpg IMG_1079.JPG 101_0302.jpg IMG_1080.JPG IMG_1081.JPG IMG_1083.JPG Set61_07.jpg
Set61_08.jpg IMG_1082.JPG IMG_1101.JPG Set6l_03.jpg Set61_01.jpg IMG_1085.JPG IMG_1086.JPG IMG_1094.JPG IMG_1087.JPG
IMG_1088.JPG IMG_1095.JPG IMG_1100.JPG IMG_1092.JPG IMG_1093.JPG IMG_1098.JPG IMG_1089.JPG IMG_1091.JPG IMG_1090.JPG
IMG_1120.JPG IMG_1118.JPG