Joinmax Digital Quadruped

via Pololu

This excellent quadruped robot kit includes all of the components you need to build your own four-legged, walking robot. Each leg has two degrees of freedom provided by a lifting servo and a forward/backward rotating servo. Eight servos provide enough degrees of freedom for you to explore various four-legged walking gaits and motions; make it scamper across the floor, turn in circles, or do a victory dance.

With all mechanical components, a 16-servo controller, PC software, and a download cable included, this walking robot kit is very complete: the only thing you need to add is five standard, AA size batteries. NiMH cells are recommended because of the high current consumption of the robot. This kit is equivalent to the hexapod monster without one of the body segments, the tail, and the gripper (even the packaging is the same, making it seem as if some parts are missing when you first open the box). However, it is an economical alternative and developing gaits for four legs is an exciting challenge.

All of the components are precision molded, and you won’t need to tape or glue anything in place. All you will need are a small phillips screwdriver (though wire cutters might make things a bit easier). Assembly time is under 2 hours, even for a beginner. The only criticism we have of the kit is that the instructions are incomplete and apparently written by a non-native English speaker, but the kit is simple enough that the drawings alone should be sufficient.

The included software allows you to manipulate the servos and store sequences of positions. A sequence of up to 60 positions can then be downloaded and stored in the servo controller so that the robot can move without being tethered to a computer. Of course, you can instead provide your own control system and sensors to make a completely autonomous robot. (The servos are compatible with regular radio control model servos, so all you need to control them is a 1-2 ms, 5-volt pulse repeated every 20 ms.)

For more information, including video clips of the robot in motion, see the manufacturer web page.

Note: The Joinmax Digital quadruped is a kit;assembly is required. Five AA batteries are required but not included.