I am using Arduino Uno + CNC shield + 2 A4988 motors on X and Z to move a stepper motor. The code works fine in the instant I disconnected all USB and switched off power supply. Then I got another A4988 motor to put on Y, but it heated up and motor kept vibrating so I switched off and removed it.
Now I can say Y driver might have burned up due to wrong settings of potentiometer
But then when I ran code for Z again I found it is not moving as well ( here am using a motor of input 1.2 A, while X and Y had 0.4 A motor) but X is working just fine.
I have following doubts to clear up:
Why this happened ( especially am curious why Z driver stopped working) ?
Suggest me some way to check driver operation and prevent burning up more of them (my PI is little bit annoyed with me)?
Which stepper motor? What is the motor's rated phase current? What is the motor's phase resistance? What is the A4988's maximum rated current? Did you adjust the pot before connecting and running the motor?
You have 3 motors rated 1.2A per phase, each motor has 2 phases so 2.4A times 3 = 7.2A. Looks like you need a bigger power supply or reduce the current limit for each motor.
No I have 2 motors of 0.4 A and only one of 1.2 A. Also I am not running all of them simultaneously as per code only one at a time based on conditional switch.
KEY FEATURES OF STEPPER MOTOR NEMA-17 1.2A KS42STH40-1204A:
4-wire bipolar operation
Compatible with NEMA17 standard
Dimensions: 42 x 42 x 40mm
Motor shaft diameter: 5mm
Step angle: 1.8 degrees
Step Count per revolution: 200
Standard Voltage: 2V
Phase current: 1.2A
Phase resistance: 1.7 ohm
Holding torque: 4N.m (minimum)
Where do you see the rated current of 0,4A? From the electrical data I can only see 1.2A. But off course you can operate it with coil current set to 0.4A at the A4988.
