A Californian company claims to have developed the world`s first all-in-one Nema 11 microstepper motor with driver, controller and encoder integrated into the back cap, thus minimising external electronics and wiring. Arcus Technology’s DMX-K-SA-11 stepper motor is aimed at size-sensitive applications requiring open-loop microstep motion with real-time position confirmation.

Most other stepper motors run open-loop with sensors to detect position values after a move. Arcus’ 16-microstep machine is capable of full, half, quarter or 1/16 microsteps, and comes in three stack sizes. The motor, which has a trapezoidal acceleration profile control, is designed for applications that need a position verification signal from the motor.

The eight-bit magnetic encoder chip, supplied by Renishaw, senses the angular position of a diametrically polarised, cylindrical magnet above it. A circular array of Hall sensors around the centre of the chip detects the magnetic flux density distribution and delivers a voltage representation of this distribution. Sine and cosine outputs from the Hall sensors vary with the magnet position, and are converted to an absolute position. The small size of the chip allowed Arcus to keep the motor within the 1.1-inch-square Nema 11 form factor.