Wind-Up Drawing Robot
The third robot in our series of homemade robots (1,2) uses the wind-up motor we harvested from a lame Bee Movie toy. (Ah, I get it now... "Bee Movie." Heh.) It draws with marker legs as it vibrates around on a piece of paper. We developed this based on an idea I saw here, which was actually what got me interested in creating toy robots in the first place.
We used a cheap plastic cup as the body of the robot, taping the markers to the interior cup wall. Since this wind-up eccentric-weight motor is relatively weak, we ended up cutting down the cup to about half its original size to lighten the load.
The trickiest part was incorporating the motor into the body of the bot so that only the winder was visible. The toy the motor came from was similarly designed, so when we removed the motor from its bee case the winder popped off. For a while we used it as a sort of key to wind the motor, but I knew if we stuck with that it would soon be lost, and I didn't want to glue it onto the motor for fear I'd gum up the gears in the process.
After covering the cup and markers in masking tape - a technique I came up with to allow for easy painting on plastic surfaces that also gives objects a cool papier-mache look - I positioned the motor inside the cup and cut a hole in the side to put the winder through. I carefully taped the motor to the cup with several small strips of tape, making sure not to block the action of the small eccentric weight on either side. Then I inserted the winder through the hole I'd made and taped around it to decrease the hole size so that the winder's peg, which had a head larger than the stem, was locked into the cup.
See this robot in action:
Past robot projects: