They came over me with full force. I did not expect them to be this powerful. Hopefully they all lose their energy very soon ... ;-)
Step 1: What you need
out of old pc mainboards I got battery holders and 3V button batteries. Also LEDs or resistors could be sourced out of old electronic parts.
To make the radio controlled mover I bought a bunch of radio controlled mini cars. I got 27Mhz and 40Mhz cars so that I can guide two robots at the same time.
Step 2: The Headbanger
The legs are made with the contacts of LEDs. These legs are rather soft. Together with the hight center of mass, the motor is mounted rather high, it leads to the slow "headbanging". As you can see in the video, this bot is moving!
After some fun with the simple version I attached a small switch that I found in an old floppy disc drive. This switch is activated when the motor "headbangs" to the side of the switch. It is deactivated when the motor moves the "rumble masses" to the other side. This leads to some oscillation.
The advantage of the soft legs are also the disadvantage of the bot. After a lot of "headbanging" the legs will break. Now we see ... IT'S DANGEROUS!