Product Description:

The CTP20NLS21NAA00 stepper motor is built by Kollmorgen as part of the CT Stepper Motors series and belongs to the Cool Torque Performance line, which is the high-torque variant within that family. This short-stack motor provides open-loop motion for indexing tables, small gantries, and pick-and-place axes that require repeatable positioning. Because it uses a short-stack design, it suits compact axis layouts where installation depth is limited. It is intended for applications that use open-loop step commands rather than encoder feedback. The motor weighs 1.0 lb (0.45 kg), uses a round smooth shaft, and mounts through NEMA through holes, allowing it to fit standard Size 23 frames without adapter brackets.

The motor has a step angle of 1.8°, which produces 200 full steps per revolution with a ±3% accuracy window. In bipolar operation, the winding is rated for 2.1 A DC per phase through six color-coded leads, and the phase resistance is 1.83 Ω. The winding produces 0.71 N-m of holding torque, and the rotor inertia is 0.0026 oz-in-s² for quick start-stop profiles. The housing follows Size 23 dimensions with a 5.7 cm square face, and the leads exit axially from the rear without a rear accessory configuration. Insulation resistance is 100 MΩ, and the thermal resistance is 3.99 °C/W, which helps the coils remain within class limits when ventilation is available.

The 2-phase inductance is 2.2 mH, which helps moderate current ripple during microstepping. This inductance level also supports smoother current control when the motor is used with modern microstepping amplifiers. The insulation rating is 340 VDC, which supports use with higher bus voltages on compatible drives. Radial loading at the shaft center is limited to 20 lbs, and axial thrust can reach 50 lbs in either direction, allowing moderate belt tension or lead-screw preload without additional bearings.