I have a laser engraver running on an Eleksmaker Mana SE controller board with a4988 drivers.
Y axis has 2 nema17 steppers running off the same stepper driver.
Wanted a 3rd axis for rotary, so I got an Arduino nano with cnc shield v4 with a4988, and got it working.
But this will not drive the 2 steppers on the same driver - driving one stepper is perfect, but with two steppers it just hums a bit, only moving the axis if i gently push it.
Hi,
according to what I read about the A4988 its meant to control one stepper. If you want to run two steppers then get a second A4988.
They need to be set up identically and then the Step and Direction inputs from the Arduino is paralleled to both drivers.
It sounds like your steppers may be driving opposite directions. They'd need to be, combined, within the drive capacity of the driver and aligned in step with each other with stepping in the same direction.
If the board (I confess I didn't look it up) is doing any kind of sensorless vector controls and not simple open loop stepping, then it will not typically work on two motors on a single driver unless specifically supported.
A4988 can ( just ) handle two small stepper motors. It's done in many 3 d printers. However, take care for the cooling if you do this.
there are several improved pin compatible replacements which can handle a bit higher current. Have a look at the TMC2209 for example.
Or if you know how, do as Craig said, run two stepper drivers in parallel. Al inputs are in parallel, and only the output to each motor is NOT parallel but connected to one motor.