Building Real-World Star Wars Droids

There are many very valid criticisms to be made about The Walt Disney Company, but one cool thing it does is fund some interesting engineering work. Disney’s teams of “imagineers” do an incredible amount of R&D to bring the company’s parks to life and much of it is genuinely groundbreaking. For an example, take a look at the droids wandering around the Star Wars: Galaxy’s Edge areas in Disneyland and Walt Disney World. They’re sophisticated bipedal robots that walk untethered around people and obstacles. James Bruton was as impressed as the rest of us, so he decided to build his own real-world Star Wars droid.

That was no small feat, because bipedal robots are still a serious challenge. A reliable bipedal gait is hard to achieve — there is a reason that it is so uncommon in the animal kingdom. Even the world’s most talented robotics companies, such as Boston Dynamics, struggle to build robots that can walk on two legs without frequent failures in the real world.

Bruton is just one man with a limited budget, so he had to cut some corners. His bipedal robot design is a similar size and shape to Disney’s droids, but only uses 3D-printed parts and off-the-shelf components. Each leg is a parallelogram, so the feet can lift while remaining level with the ground. Heavy duty servos in the hips actuate the legs, while additional servos in the knees actuate just the lower legs. The hips also have two other servo-actuated joints that let the legs pivot and rotate. Those are necessary for a reliable gait and turning. Finally, one more servo gives the head some movement.

The control electronics consist of a Teensy 4.1 development board paired with an inertial measurement unit (IMU). That IMU is there to monitor the movement of the robot in order to compensate for shifting forces and maintain balance. Bruton can pilot the robot using his universal remote that sends commands to the Teensy through an OrangeRX DSM radio receiver.

This works well enough for the robot to stand upright and take small steps, with some attempts to try and turn. It can’t compare to the amazing work done by Disney’s imagineers, but it is still impressive for one person working alone.