Petoi, the team behind the open-source Bittle and Nybble quadruped kits, has opened early access for its next robot, Quaddle. The company describes it as a four-servo quadruped capable of walking, strafing sideways, and spinning in place, a claim that stands out mainly because of how few actuators it uses to pull it off.
Most legged robots that can move in multiple directions rely on two or three degrees of freedom per leg, so each foot can be steered independently. That approach is how machines like MIT's Cheetah or Petoi's own Bittle X, which uses nine servos, achieve lateral and rotational motion. Quaddle instead uses a single motor per leg, paired with a mechanical linkage the company says drives both the hip and knee joint together. With only one actuator per leg, any sideways or rotational movement has to come from how the gait is timed and phased across the four legs rather than from independently steerable feet. Whether the result is a clean pivot or something closer to a coordinated shuffle isn't clear from the promotional material, and Petoi hasn't published mechanism or gait details yet.
The firmware runs on OpenCat, the same open-source codebase used across Petoi's existing robots, so the coding stack (block-based coding, Python, C++ via Arduino IDE, and ROS) carries over. Openness has limits though: Petoi has confirmed it will release 3D-printable shells and mounts, but the load-bearing joints will remain injection-molded rather than open hardware, citing durability under Quaddle's dynamic movements.
Quaddle is planned in three configurations, Builder, Buddy, and Scout, with early-bird pricing starting at $99 and topping out at $179 for the sensor-equipped Scout model, which adds gesture, light, and infrared sensing. All three include a Raspberry Pi Zero socket and support for Arduino or ESP32 add-ons.
The project is still in a pre-launch phase, with no schematics, BOM, or firmware repository published for Quaddle specifically. A full technical read will have to wait until hardware ships.
