Product Description:

The S21HNNA-RNN6-00 is a 6-pole Neodymium magnet brushless servo motor manufactured by Pacific Scientific within the S Brushless Motors series. It is intended for tightly regulated industrial automation axes in applications such as pick-and-place modules and indexing stages, where repeatable velocity and position are required. The unit follows the NEMA frame mounting standard and routes power plus resolver leads through a rear-facing MS connector. A size 21 frameless resolver supplies primary feedback, and there is no secondary feedback device, shaft seal, or integral holding brake, making the motor suitable for clean, cabinet-mounted installations where external brakes or seals are supplied by the machine.

The motor delivers a continuous stall torque of 0.5 Nm so it can hold loads without thermal overrun while energized. During rapid accelerations it can reach a peak torque of 1.36 Nm, giving short-term headroom for indexing moves or overcoming static friction. The line-to-line inductance is 3.7 mH, which influences the electrical time constant and how quickly current can be modulated by the drive. A phase-to-phase resistance of 3.0 Ohms establishes the copper loss at rated current and helps the drive calculate expected heating. With a torque constant of 0.2 Nm/ARMS, each ampere of sinusoidal phase current produces one-fifth of a newton-meter, allowing the controller to translate commanded current into mechanical output precisely. These electrical characteristics correspond to winding type H and are optimized for low-inertia applications that operate from moderate bus voltages.

A weight of 1.4 kg permits direct mounting on lightweight gantries without excessive load on bearings. The frame adheres to the NEMA 23 size code, so it mates with standard gearheads and mounting brackets used on compact motion assemblies. Dynamic response is aided by a rotor inertia of 0.042 × 10⁻³ kg·m², keeping acceleration times short during frequent start-stop cycles. A voltage constant of 0.13 VRMS/rad/sec corresponds to the back EMF generated at speed and allows the drive to predict regenerated energy.