Product Description:

The CTM21NLF25NAA0 is a size 23 stepper motor manufactured by Kollmorgen for the CT Stepper Motors series. It belongs to the Cool Torque Maximum series and serves as a positioning element in automated machinery that requires repeatable step movement without feedback devices. A round, smooth shaft and NEMA through-hole mounting allow direct coupling to pulleys, lead screws, or gearheads in packaging lines, pick-and-place tables, and small conveyors. Because it is a stepper motor, it is well suited to indexing and positioning tasks that benefit from predictable open-loop motion.

The motor develops a holding torque of 260 oz-in, which is the static torque available to keep a load stationary when the coils are energized. Each phase is driven at 2.5 A DC, and the 3.7 VDC winding rating helps limit copper losses during operation. Motion is produced in 200 full steps per revolution, with each step measuring 1.8° and having an accuracy of ±3%. Dynamic response is influenced by a phase inductance of 4.2 mH and a phase resistance of 1.48 Ω, which affect current rise in microstepping drives. The detent torque is 13 oz-in when the driver is off, and a single-stack rotor has 0.0035 oz-in-s² of inertia. The CTM winding supports bipolar operation during acceleration, which is useful in applications that need quick indexing and stable step response.

Mechanical limits include an axial load of 50 lbs in either direction and a radial load of 20 lbs at the shaft center, so couplings should be aligned to reduce bearing stress. The insulation system is rated for 340 VDC with 100 MΩ resistance, and the thermal resistance is 3.57 °C/W for heat transfer to ambient air. This thermal behavior helps the motor operate in compact machine spaces where heat must move through the frame efficiently. Overall weight is 1.5 lb, which supports compact axes where low moving mass is useful. Four lead connections simplify wiring, no rear add-ons are installed, and the 5.7 cm frame dimension matches standard NEMA 23 brackets.