Boring AT-AT Toy Becomes Impressive Robot

The original Star Wars trilogy was successful for a variety of reasons, but a massive amount of the credit goes to the ILM (Industrial Light & Magic) team. They were responsible for the special effects and developed all kinds of imaginative fictional technology for the films. In The Empire Strikes Back, the massive AT-AT walkers striding across the icy terrain of the planet Hoth were a visual marvel. As such, many AT-AT toys have hit the market over the years. But while they're often posable, they usually aren't capable of walking on their own. James Bruton decided to change that by building a robotic AT-AT toy.

Bruton started with a large AT-AT toy, similar or identical to the toys many of you owned in your youth. That toy has posable legs and even an articulated head that the owner can operate with a mechanical linkage in the body. But that toy didn't have any motors, so it couldn't actually walk like the on-screen behemoths. That toy served as the inspiration and model for Bruton's robot.

Using the toy as a reference, Bruton designed a new robot in CAD. It carries over the approximate size and shape of the original, and walks likewhat we all saw in the movie. But it isn't an exact replica, because Bruton didn't duplicate all of the design elements. The entire robot was 3D-printed and walks on four legs, each actuated by three servo motors. The legs are parallel linkages, which helps to keep the foot of each leg level withthe ground. One servo rotates the hip, one rotates the knee, and the final servo pivots the entire leg on a horizontal plane to enable turns.

As usual, Bruton used an Arduino Mega 2560 board to control the servo motors. That receives commands through a DSM radio receiver from the universal DSM remote transmitter that we featured previously. Bruton explains some of the geometry theory that went into the leg movement and walking gait, which was necessary to keep the robot stable. But even with that theory, it was front-heavy. That forced Bruton to put the battery and heavy nuts on the back of the robot to gain better balance.

The finished AT-AT robot may not look exactly like the real deal, but it walks like it. If you want to build your own, Bruton published all of the CAD and code on GitHub.