Product Description:

The CTP21NLF04NAA00 is a two-phase stepper motor produced by Kollmorgen for the CT Stepper Motors series and belongs to the Cool Torque Performance Series. This model uses a 1-stack rotor design to deliver incremental motion in pick-and-place stations, small conveyors, and metering pumps where open-loop position control is acceptable. It provides high torque density while fitting within the Size 23 (57.2 mm square) frame that mounts through standard NEMA through holes. That frame size also suits compact machine layouts with limited mounting space.

The motor develops a bipolar holding torque of 1.41 N·m when driven by the specified winding current of 0.45 A per phase. Four color-coded leads simplify connection to common microstepping drives, and each of the two phases has a resistance of 44 Ω, limiting current at standstill while helping the winding withstand an insulation voltage of 340 VDC. A phase inductance of 170 mH shapes the current rise time, which supports smooth low-speed operation and keeps detent oscillations low; residual detent torque is 0.06 N·m. The motor can operate safely at speeds up to 3000 rpm, so the same drive can run rapid indexing moves without exceeding back EMF or bearing limits. A low rotor inertia of 0.000025 kg·m² helps reduce start-stop energy loss during repetitive motion.

The laminated core is only 53.7 mm long and weighs 0.64 kg, which helps keep the motor suitable for light gantry axes and other moving assemblies. The motor has a round, smooth shaft that is 6.35 mm in diameter and 20.57 mm long, and it is rated for 50 lbs of axial load and 20 lbs of radial load at the shaft center, allowing moderate belt tension or thrust coupling. The single-ended shaft turns 1.8° per full step, and the housing has no rear add-ons, so it can clear tight encoder mounts or gearbox adapters without interference.