The Hexapod for the Rest of Us

James Bruton is no stranger to big, complex robot builds. Over the years, we have seen everything from a Star Wars BD-1 droid to a one-wheeled balance ball bike come out of his workshop. But while these creations are impressive, and watching the project videos is loads of fun, there is no way that most people can even come close to reproducing these builds.

So, for a change of pace, Bruton has taken on the challenge of designing a robot that we can all actually build at home. It is a very cool hexapod robot, and it is completely open source. The project is being built in a series of videos, and the latest focuses on one of the most difficult tasks — making it walk.

Bruton introduces what he calls “anti-inverse kinematics,” a clever rethinking of how walking robots are typically designed. Traditional hexapods rely on inverse kinematics (IK), a mathematically intensive process that calculates the angles of multiple joints — usually 18 across six legs — to achieve smooth, coordinated motion. Bruton’s approach sidesteps that complexity entirely.

Instead of relying on trigonometry-heavy calculations, the robot’s movement is built directly into its mechanical structure. Using rack-and-pinion systems, each leg moves strictly in straight vertical lines. This means that each motor corresponds directly to a single axis of motion, dramatically simplifying both the hardware and the control logic. The result is a robot that uses just eight servos rather than the usual eighteen, making it far more accessible to hobbyists.

The design itself relies heavily on 3D-printed components, primarily using PLA for structural parts and TPU for flexible, grippy feet. Precision is critical, especially for the rack-and-pinion assemblies, which are printed in a way that maximizes gear tooth definition. Bearings — standard skateboard-sized — are integrated into the structure to guide the linear motion smoothly and prevent wobble.

One of the most innovative aspects of the build is its dual-tripod system. The six legs are divided into two sets of three, mounted to independent upper and lower frame layers. These layers can slide relative to one another, creating forward motion, while a central pivot allows for rotation. A dedicated servo drives a curved gear segment, enabling the robot to turn by rotating the two layers against each other by up to 25 degrees in either direction.

Control is handled by a pair of ESP32 microcontrollers communicating via ESP-NOW, eliminating the need for a traditional Wi-Fi network. A handheld remote with an analog thumbstick provides the user input, while onboard code uses a multitasking state machine to coordinate movement. Rather than relying on blocking delays, the system checks timing continuously, allowing for smooth transitions between lifting, sliding, and placing each tripod.

The walking gait ensures stability by always keeping three legs on the ground, making the robot surprisingly capable on uneven terrain like grass. It’s a nice demonstration of how good mechanical design can replace computational complexity.

By making the entire project open source, complete with CAD files, Bruton is not just showing off his latest creation. He’s making complex robotics accessible to even the weekend hobbyist.