Product Description:

The CTM21NLF39NAA00 is a 2-phase hybrid stepper motor built by Kollmorgen for the CT Stepper Motors series and included in the Cool Torque Maximum Series portfolio. It converts discrete control pulses into indexed rotary motion, making it suitable for positioning slides, small conveyors, and metering pumps in automated equipment. Kollmorgen’s Enhanced Series emphasis on maximum torque and efficiency allows this model to deliver rated performance while fitting inside compact machines that use a round shaft and a NEMA through-hole mounting pattern.

This motor supplies a holding torque of 1.84 N-m while drawing 3.9 A DC per phase through four color-coded leads. The copper windings present a winding resistance of 0.60 Ω and a phase inductance of 1.6 mH, which affect drive sizing and current rise time. With a step angle of 1.8°, the rotor advances 200 full steps per revolution, giving predictable resolution without micro-stepping. Thermal energy moves from the stator to ambient at 3.57 °C/W, and the insulation system tolerates 340 VDC with 100 MΩ resistance to ground for electrical isolation. A detent torque of 0.09 N-m helps prevent unintended drift when the coils are de-energized, and the 0.000025 kg-m² rotor inertia supports quick acceleration. Leads exit the front housing because there is no rear cable exit, simplifying cable routing in tight panels.

The motor installs in a Size 23 frame that is 5.7 cm wide and weighs 0.68 kg, easing integration on linear stages that cannot accept heavier motors. The round shaft end can absorb up to 50 lbs of axial load in either direction and 20 lbs of radial load at the center, matching belt tension or gear overhang forces typically seen in light-duty indexers. A single-stack construction keeps the overall length short while maintaining high output per volume.