The AX-12W is a variant of the popular AX-12A servo with modified gear reduction to offer high speed in Wheel Mode (continuous rotation mode). (in Joint mode the actual moving speed is close to the AX-12A)
The AX series of servos can be connected in a daisy chain, and controlled over a Serial protocol meaning several servos can be connected to each other in a chain and offer several compliance and sensing parameters including position, velocity and temperature.
The AX-12W has the same exterior size and shape as the AX-12A and the AX-18A using the same communication interface and protocol. This means that all these Servo models can be mixed and matched to meet the specific demands of Robotic applications.
AX-12A vs. AX-12W speed comparison in Wheel Mode
This high speed comes at the expense of a lower holding torque: the AX-12W has a 2kgf.cm torque versus the 12kgf.cm offered by the AX-12A.