💡 Voltage Assessment: With 1.5 mH inductance, a 24V PSU delivers great performance. Stepping up to 36V or 48V allows printing past 400 mm/s with zero torque drop-off.
Bipolar stepper motors are constant-current devices. As rotational speed (RPM) increases, two physical phenomena impede the motor from achieving rated torque: winding inductance ($L$) and rotational back-electromotive force (Back-EMF). Choosing the optimal power supply voltage and driver reference voltage ensures your 3D printer or CNC machine accelerates crisply without overheating motors or losing positional synchronization.
The Geckodrive 32√L Maximum Voltage Formula
V_max = 32 × √(Inductance_mH)
This empirical formula balances the drive voltage required to force current into inductive coils against core iron eddy current heating. Motors with low inductance (1.0 to 1.8 mH) are ideal for high-speed CoreXY 3D printers, whereas high-inductance motors (4.0+ mH) are speed-limited and perform poorly above 200 mm/s.
Frequently Asked Questions
Why does Klipper use rotation_distance instead of steps_per_mm?
Klipper decouples mechanical hardware geometry from driver microstepping. The rotation_distance parameter depends purely on physical mechanical parts (belt pitch, pulley tooth count, or screw lead), meaning changing microstepping from 16 to 32 does not require recalibrating motion steps.
What temperature should stepper motors operate at?
Quality NEMA 17 motors are rated for Class B ($130^\circ\text{C}$) or Class F ($155^\circ\text{C}$) internal insulation. A motor operating at $50^\circ\text{C}$ to $70^\circ\text{C}$ (warm or hot to the touch) is completely normal and operating within healthy thermal tolerances.