FAULHABER Whitepaper Stepper Motor Technical Note: Microstepping Myths and Realities

Stepper Motor Technical Note: Microstepping Myths and Realities The lure of Microstepping a two-phase stepper motor is compelling. Visions of Microstepping a 1,8-degree hybrid stepper motor with 256 microsteps per full step flash in your mind. The resolution of 51.200 microsteps per revolution entices you. You’re glad you don’t own stock in high- resolution encoder companies. Publisher / Editor: DR. FRITZ FAULHABER GMBH & CO. KG Schönaich · Germany Email: [email protected] www.faulhaber.com © DR. FRITZ FAULHABER GMBH & CO. KG · 2020_05 · Specifications subject to change without notice · See also...

Stepper Motor Technical Note: Microstepping Myths and Realities Torque vs. shaft position Equilibrium position θ [rad] Dotted line: Suitable response for precise microstepping positioning. Blue line: Distorted curves. The actual expression for incremental torque for a single microstep is 1.: The real compromise is that as you increase the number of microsteps per full step, the INCREMENTAL torque per microstep drops off drastically. Resolution increases. However, accuracy will suffer. Few stepper motors have a pure sinusoidal torque vs. shaft position and all have The incremental torque for N...

Stepper Motor Technical Note: Microstepping Myths and Realities Incremental Torque per Microstep/Full Step % of Full Step Holding Torque. at 16 Microsteps per Full Step the Incremental Torque for one Microstep is less than 10% of the Full Step Holding Torque Microsteps per Full Step Table 1 dramatically quantifies the significant impact on the incremental torque per microstep as a function of the number of microsteps per full step. A full step is considered one microstep per full step for Equations 1 and 2. Incremental Torque per Microstep As the Number of Microsteps per Full Step Increase What...

Stepper Motor Technical Note: Microstepping Myths and Realities What if the motor is not loaded? Thinking of using microstepping for some type of pointing or inertial There are still compelling reasons other than positioning? Well, the stepper motor still has friction high resolution for microstepping. They include: torque due to its bearings and it has a detent torque (in reduced Mechanical Noise addition to other harmonic distortions). You’ll have to gentler Actuation Mechanically “wind up” enough incremental torque to overcome the reduces Resonances Problems bearing friction. Even more disruptive...