Motors Cheap geared motors from Rapid Electronics. Behaviour Havoc trotts forward at quite a rate. His legs skid a lot. I think he could be better balanced. He has fine antenna at the front that trigger Havoc to reverse for a time if they detects an obstruction.
Havoc drains batteries at an alarming rate.
If you've got a pair of 3 D glasses to hand give the image above a go. The red lense should cover the left eye. C lick H ere to download a short MPEG movie of Havoc taking a few steps. C lick H ere to download a short MPEG movie of Havoc colliding with an obstruction and backing up.