Product Description:

The CTM21NLS31NAA00 is a two-phase stepper motor produced by Kollmorgen as part of the CT Stepper Motors series. Within the Cool Torque Maximum Series, this model is an enhanced design that delivers high torque and efficiency for precise indexing and feed control in industrial automation. A Size 23 frame measuring 5.7 cm across the face and a single-stack lamination package keep the unit compact while providing the flange pattern commonly used in pick-and-place modules, small conveyors, and packaging machinery.

Electrical performance depends on torque and current. The CTM winding supplies 1.84 N-m of bipolar holding torque, while the alternate CTP winding supplies 1.41 N-m, allowing the motor to be matched to the intended duty cycle. The motor draws 3.1 A DC per phase, and as a two-phase device, simultaneous excitation develops the required field without overstressing the insulation system. Winding behavior is characterized by a phase inductance of 1.4 mH and a phase resistance of 0.97 ohms, values that affect current rise time, copper loss, and microstep smoothness. Six leads support series or parallel wiring, and the standard step increment of 1.8° provides 200 full steps per revolution for direct position calculations.

Mechanical ratings support reliable coupling to external loads. The round smooth shaft accepts axial thrusts up to 50 lbs (23 kg) and radial forces of 20 lbs (9 kg) at the centerline, so small pulleys or ball screws can be mounted without auxiliary bearings. The windings are insulated for 340 VDC, which supports operation with high-voltage microstep drives. Low rotor inertia of 0.000025 kg-m² allows rapid acceleration, and the motor's 0.68 kg mass can be fastened to a machine frame through the NEMA through-hole pattern. The motor has no rear shaft configuration, which keeps the overall length short and leaves the user free to route conductors directly into the control enclosure.