Product Description:

The P21NRXB-LNF-NS-00 is a two-phase stepper motor produced by Pacific Scientific for the POWERMAX II P Motors series. It translates pulse trains from an external drive into accurate incremental rotation, making it useful for pick-and-place stations, index tables, and compact gantries that need open-loop positioning without encoders. Because rotation is produced in fixed increments, the motor is well suited for feed mechanisms and indexing tasks that need predictable step-by-step motion. No feedback device is installed, so position tracking depends on the commanded step count and the load staying within the motor's available torque during operation.

This model uses a B winding on one stack, giving a full-step increment of 1.8 degrees and 200 steps per revolution. Positional deviation is limited to ±1.5%. Unpowered detent torque is 4 oz-in, while energized holding torque reaches 111 oz-in. A low rotor inertia of 0.0017 oz-in-s² supports rapid starts and stops, and the standard rotor design helps maintain smooth microstepping. Thermal resistance is 5.5 °C/W, and the motor operates in an ambient range of -20 °C to +40 °C. Coil insulation is rated at Class B, 130 °C, backed by 100 MΩ insulation resistance and a 340 Vdc hipot rating. Two lead wires exit through a regular receptacle to support series or parallel connections, and the construction is standard.

Mechanically, the frame follows the NEMA 23 pattern, and the single, flat-milled shaft measures 0.2500 in in diameter for easy coupler clamping. The flat on the shaft provides a stable contact surface for set-screw couplings used on light automation axes. Bearings accept radial forces up to 20 lb and axial forces up to 13 lb. Overall mass is only 1.5 lb, minimizing payload on moving axes. The mounting style is NEMA, the rotor type is standard, and the shaft is single-ended.