A BLDC motor takes advantage of the mechanical balance between a set of coils and magnets to control the movement of the magnetic armature - pulling harder on one couple while releasing the force on another so that both speed and position can be controlled. This is normally used to provide constant spin or, in the case of a linear motor, constant position control in one linear axis.
There are, however, other configurations where the same balance of opposing forces can occur but without linear or rotary motion. One such is the swashplate : three actuators balance each other against a central pivot. Although it is used as a rotary to reciprocal movement converter this is something of a compromise, relying on a sliding surface.
I would like to experiment with a TAPAS controller in a swashplate configuration to provide a controlled angular - not rotary - motion of a few degrees tilt exerted in a 360 degree direction - a 2D pointing movement.
This has application in robot legs (controlling direction of actuator force), robot feet (balance), prosthetics (limb angles, foot balance), 3D positioning (when used with a supplementary linear actuator) and, in conjunction with a mirror, light-pointing applications such as the galvanometer actuators in laser displays and SLA 3D printers. A chain of such devices could be assembled into a prehensile actuator.
The force available is limited due to variable magnetic gap but the central pivot avoids the actuators taking the main force - they only have to provide the differential force.
The idea could be investigated using a single TAPAS board, but many practical applications (I am particularly interested in active balance for robotic or prosthetic feet) would require a pair.