While revisiting the geometry and simulation of sensor excitation, I realized that rotating the sensor around the (1,1,1) axis is not sufficient to fully resolve the sensor bias — especially the component along the Z axis.

A single degree of freedom in rotation doesn’t provide enough information to separate sensor bias from the actual field vector in all three dimensions. In particular, the Z component remains insufficiently excited during this motion, making it difficult to reliably estimate its offset through averaging or Kalman filtering.

To overcome this, I’ve decided to add a second rotational axis. A second servo motor will be integrated into the base of the rotating assembly, and its motion will be transmitted to the upper turret via GT2 belts.

Mechanically, this second axis will rely on an aluminum shaft and a bronze sleeve, press-fitted into a PLA structure. This ensures mechanical rigidity while avoiding paramagnetic or ferromagnetic materials in motion near the sensor, which could otherwise corrupt the magnetic readings.

This upgrade should allow the sensor to explore a much larger portion of the 3D orientation space, improving the ability to identify and compensate for biases on all axes, including Z.