DIY Autonomous Quadrotor

My first complete autonomous multirotor, built from parts rather than from a kit: a custom frame, motors and ESCs chosen against the intended all-up weight, and an Ardupilot flight controller as the brain.

Getting a multirotor into the air is the easy half. Getting it to hold a position without drifting means a properly calibrated IMU and, above all, a properly calibrated compass — mounted far enough from the power wiring that the motor currents do not pull the heading around, which is the classic first-build mistake and the one that costs the most flights to diagnose.

Once the platform hovered reliably, the interesting part began: planning waypoint missions on a map, uploading them, and watching the aircraft fly a route it had never been flown through manually.

This is the project everything else in the RC section grew out of. The Ardupilot toolchain, the tuning workflow, and the habit of testing one change at a time all started here, and they carried directly into the Y4 and the VTOL work that followed.