Glossary · Motion control and drives
Full step
Also known as: Full-step mode, Full-step operation
German: Vollschritt
In stepper motor control, a full step is the smallest rotor movement the motor makes when the driver switches the winding currents from one of its basic energizing states to the next; its size is the motor's step angle, for example 1.8° or 200 full steps per revolution.
- Motion control
In one sentence
A full step is the basic rotor movement of a stepper motor between two energizing states; its size is the step angle, often 1.8°.
Example
A dosing pump's stepper motor with 200 full steps per revolution turns the spindle by 1.8° for each full step the driver outputs.
How it applies
- Engineering: In full-step mode both phases are energized with full current (or one at a time in wave drive). Half-step mode alternates between one and two energized phases and halves the step size; Microstepping subdivides the full step further.
- Commissioning: Full-step operation gives the highest torque per step but runs rough and is prone to Stepper motor resonance at low speeds.
- Operation: The motor's natural stable positions are its full-step positions, which matters when current is reduced or switched off at standstill.
- Documentation: State whether a figure refers to full steps, half steps or microsteps. "Steps per revolution" without that qualifier is a common source of scaling errors in parameter tables.
Full step vs. half step
A full step moves the rotor by one step angle. A half step moves it by half of that, by inserting an intermediate state in which only one phase carries current. Half-step mode doubles the resolution, but the torque varies between the one-phase and two-phase positions unless the driver compensates the current.