it looks like it is set at 2x microstepping when I received it. What benefit will I get if I change it to 4x microstepping?
I would like to know the same thing.
In theory you gain resolution at the cost of speed and torque when you increase the microstepping.
But in reality even with a gain in resolution you do not even gain much in the way of true accuracy due to bearing friction and detent torque. At some point, depending on the motor microstepping can even result in the loss of accuracy.
So the only real reasons to increase the microsteps are:
- Reduction of Mechanical Noise.
- Gentler Actuation Mechanically
- Reduction of Resonances Problems
The reduced torque is a very common misunderstanding - motor torque is roughly the same for every microstep setting.
What decreases is the “incremental torque” between 2 microsteps. Microstep positions are “soft” and springy - it is easy to deflect the motor axis between microsteps without losing steps.
The advantages are noise and resonance reduction which also helps to avoid losing steps in critical resonance situations. There is no loss of torque - but also no significant increase in accuracy because of the softness of the microsteps.
Edit: There can be a significant disadvantage for microstepping: the higher the setting the more steps per second are required to reach a certain speed. If it is too large the controller won’t be able to keep up with it.
According to motor manufacturer Minebea
"Microstepping can divide a motor’s basic step up to 256 times. Microstepping improves low speed smoothness and minimizes low speed resonance effects. Microstepping produces roughly 30% less torque than dual phase full stepping. "
This is a really complicated subject compounded by the fact that there are two torque measurements in a stepper, the holding torque and the rotational torque. The motor driver itself can have a large effect on how the micro stepping effects torque depending on how exactly it is controlling the current and the timing it can achieve.