Это может у тебя домыслы.michael-yurov писал(а):И еще... есть распространенная мысль о том, что при более мелком микрошаге - падает крутящий момент шаговых моторов - это не так, он просто становится более равномерным, так что микрошага бояться не стоит.
При микрошаге и больших скоростях динамический крутящий момент падает это аксиома. Преимущество микрошага на малых оборотах, моторы работают тише и мягче.
Most people want motors to turn, not just 'hold'. As soon a full-step driven motor turns, its torque drops to 65% of its holding torque. Where did the missing torque go? To resonating the motor is where. Motor manufacturers sometimes specify 'dynamic torque'; this is specified at 5 full steps per second. It is always between 60 to 65% of holding torque. Not mentioned is the horrible racket the motor makes at 5 full steps per second.
Microstepped motors do not resonate at low speeds, so no torque is invested in resonance. Microstepped motors keep all their holding torque while turning slowly. 65% for full-steppers, 71% for microsteppers. Advantage: By a hair (6%), goes to microsteppers.
Things get a little dicey as speed increases. Microstepping ceases to have any benefit above 3 to 4 revolutions per second. The motor is now turning fast enough to not respond to the start-stop nature of full steps. You can say the step pulse rate is above the mechanical low-pass frequency limit (100Hz or so) of the motor. Motion becomes smooth either way.
Simple drives persist in microstepping anyway above this speed. This means they still try to make the motor phase currents sine and cosine past this speed. A little problem with that and it's called 'area under the curve'. The area under the sine function (0 to 180 degrees) is only 78% of a square (full-step). Advantage: Goes to full-step again.
More sophisticated drives transition from sine-cosine currents to square-wave quadrature currents about then. Same as full-steppers. Advantage: Draw.