Running two stepper motors at the same time at different speeds

Other Hardware Motors, Mechanics, Power and CNC
1

Hey all, I am trying to run two stepper motors 'simultaneously' at different speeds, and have run into an issue where I am beginning to think it may not be possible. I understand that stepper.step() does not return until the step has been completed, and therefore you use small steps such as stepper.step(1) to make it seem as though they are running at the same time, however, if they are set at different speeds and one is slower than the other, the system will end up running like they are at the same speed. Is there any way around this?

Thanks.

  • FC.

Some example code that would cause this problem:
Stepper stepper1;
Stepper stepper2;

stepper1.setSpeed(10);
stepper2.setSpeed(100);
while(true){
stepper1.step(1);
stepper2.step(1);
}

2

so it looks like the function for stepping the motor acts like a delay, the time it takes for the slowest one to return limits how often the faster motor is called to step, slowing it down. I bet if you replaced one of the motor steps commands with a delay it would slow down the speed no matter what rpm you set the stepper to (as long as you're only calling it to do 1 step).

"if you set the speed to, say, 1 RPM and called step(100) on a 100-step motor, this function would take a full minute to run"

looks like there is another library that doesn't block when you call it.
http://www.airspayce.com/mikem/arduino/AccelStepper/

3

AccelStepper library?

4

As @MarkT has said. Or just write your own code - see the second example in this simple stepper code

...R
Stepper Motor Basics