Penny#3, the $10 Hexapod

Walking robots can cost many thousands of dollars, but as shown by Penny#3, they don’t have to. This $10 hexapod, which is made out of 3D-printed parts and powered by a trio of SG90 9G micro servos, is controlled via an ATmega8 microcontroller that's soldered onto a custom perfboard, along with an 8MHz oscillator, resistors, and capacitors.

For sensing, Penny#3 mounts a pair of infrared LEDs and phototransistors, allowing it to avoid obstacles in front of it, as seen in the first video below. In order to walk, the servos — and thus the legs — go through a series of oscillations, tilting the body to one side while driving legs are repositioned, then tilting the other way to repeat the process. If it needs to back up, the sequence is modified, and while perhaps not as smooth as an animal, it does do a good job scooting around the floor.

Parts for the robot can be printed in a few hours, and STL files, parts needed, and build info on the board is available on GitHub. The hexapod looks like an easy and inexpensive introduction to robotics, and if you need more inspiration, check out the second video where it dances to the track “To My Soul” by Ace.