Product Description:

The M21NRXE-LDN-NS-00 is a hybrid stepper motor produced by Pacific Scientific as part of the POWERMAX II M Motors series. In automated machinery, it provides incremental motion control by translating command pulses from a drive into repeatable angular steps for indexing tables, laboratory dispensers, or light conveyor diverters. A double shaft and the manufacturer’s enhanced construction allow accessories to be mounted on either end while maintaining the mechanical footprint commonly expected from NEMA-style installations. This arrangement is useful in layouts that need a driven load on one side and a secondary device, such as a feedback accessory or hand-adjustment element, on the other.

This motor turns in discrete increments of 1.8 degrees, so 200 command pulses produce one full revolution without micro-stepping. The housing follows the NEMA 23 frame standard, giving a 57 mm square face that matches common mounting brackets and gearbox adapters used in compact motion systems. When the windings are de-energized, the rotor still resists movement with a detent torque of 0.066 Nm, which helps limit drift when light loads are present at standstill. Dynamic response is also influenced by a rotor inertia of 0.012×10⁻³ kg·m², which supports quick acceleration and deceleration while helping the axis remain predictable during repeated start-stop motion.

The motor body is only 52.3 mm long, which helps it fit into shallow assemblies where rear clearance is limited. An overall mass of 0.68 kg keeps the unit easy to mount and reduces added load on moving structures such as vertical slides or small transfer arms. A smooth double shaft with a diameter of 6.35 mm accepts couplings or timing-belt pulleys without key machining, making it suitable for direct integration with common power transmission components. Continuous operation is specified from -20 °C to +40 °C, and within that range the Class B insulation, 100 MΩ insulation resistance, and 5.5 °C/W thermal path help keep winding temperature within normal operating limits during typical duty cycles.