Product Description:

The CTM21NLS12NAA00 is a Size 23 stepper motor produced by Kollmorgen within the CT Stepper Motors series and grouped in the Cool Torque Maximum line. The CTM variant is intended for applications that need high torque and efficient operation from a compact frame. In automated machinery, it converts pulse trains from a drive into incremental rotation for indexing tables, miniature conveyors, and laboratory stages. Standard NEMA through-hole mounting lets the unit bolt directly to brackets and equipment plates without custom adapters. That mounting style helps the motor fit compact assemblies where repeatable open-loop motion is required. This type of motor is often used where the controller sends discrete step commands instead of analog speed references.

It produces up to 1.84 N·m of bipolar holding torque, while unipolar operation delivers 200 oz-in for applications that favor lower current demand. Each revolution is divided into 200 full steps, matching a 1.8° step angle with ±3% step accuracy. The windings have 5.89 Ω of phase resistance and 8.6 mH of inductance, which affects current rise time and helps smooth high-frequency torque ripple. Nominal excitation is 1.2 A per phase at 7.2 VDC, and the insulation system is rated for 340 VDC. Six lead wires exit the housing, giving flexible phase connections for different drive arrangements.

The motor has a round smooth shaft for coupling to belts or lead screws. The shaft tolerates axial forces up to 50 lbs in either direction and radial loading up to 20 lbs at the shaft center, which helps protect the bearings from overhung loads. Static detent torque is 13 oz-in, and the 0.0035 oz-in-s² rotor inertia helps limit overshoot when the single-stack rotor accelerates. The motor weighs 1.5 lb, and heat moves from the copper to the case through a thermal resistance of 3.57 °C/W during continuous duty. A six-lead harness exits the unobstructed rear, and the 5.7 cm frame outline suits equipment that needs high torque density without added length. The rear cable exit also leaves the shaft end clear for couplings, pulleys, or lead screw hardware.