Product Description:

The CTP21NLF25NAA00 is a two-phase stepper motor produced by Kollmorgen as part of the CT Stepper Motors series. Within the Cool Torque Performance Series, the unit delivers incremental motion for indexing tables, labeling heads, and other position-based automation. Its design emphasizes high torque in a compact package and translates discrete drive pulses into accurate shaft rotation without integral feedback devices. This operating method makes it suitable for applications that need repeatable indexing and straightforward pulse-based control.

Each of the four lead connections energizes one coil phase, and the windings draw a rated current of 2.5 A DC. At 40 °C, the winding resistance is 1.48 ohms, and the phase inductance is 5.8 mH, which helps determine supply voltage selection and current-loop response. The laminated core uses a single stack with an axial length of 53.7 mm, which keeps the motor relatively short for compact mounting spaces. With a frame size of Size 23 / 5.7 cm and a NEMA through-hole mounting pattern, the motor fits standard 57 mm faceplates. The connection style uses flexible leads, no rear accessory is fitted, and the winding insulation is rated for 340 VDC isolation.

The CTP winding option provides holding and dynamic torque of 1.41 N-m, with a detent torque of 0.06 N-m that helps resist small position shifts when the phases are not energized. Motion resolution is 1.8° per full step, which gives 200 discrete positions per revolution. The smooth round shaft measures 6.35 mm in diameter and is intended for couplings or pulleys that clamp directly to the shaft surface. Axial loading up to 50 lbs is permitted in either direction, while radial force at the shaft center can reach 20 lbs. Rotor inertia is 0.000025 kg-m², which supports short acceleration times and steady positioning, and the total motor mass is 0.64 kg.