stepper motors are vibrating but not spinning.

Hi,

I am pretty new into Arduino and trying to make a small cnc router.

I have connected the Arduino board with a GRBL based cnc shield, And as motor driver i am using DRV8825 module. As power source I am using a 12v 27aH lead acid battery to power the NEMA 17 4.2 kgcm motor.

While I am running one motor with one driver and providing manual feed from universal G-code sender, the motors is working fine. but whenever I am connecting three driver and three motors the motors are not moving.Rather they are only vibrating.

Can anyone please suggest me any solution?

Sayab:
While I am running one motor with one driver and providing manual feed from universal G-code sender, the motors is working fine. but whenever I am connecting three driver and three motors the motors are not moving.Rather they are only vibrating.

You need to explain that in more detail. For example ...

  • Can you get every one of the motors to work one at a time?
  • Does it matter which driver the motor is connected to?
  • How is everything connected when you try with one motor, and with all three motors?
  • and anything else that might help us to help you

Also post a link to the datasheet for your stepper motors.

...R
Stepper Motor Basics
Simple Stepper Code

Firstly I hope you have a suitable fuse on that battery, a 27Ah lead acid battery can do an enormous
amount of damage without a fuse.

Secondly are your wiring and connectors adequate for the current - the voltage at the motor
driver board should hold up at 12V without much droop, you should measure to confirm this.

If the voltage is drooping you have either a duff battery or poor connector somewhere.

Note that lead acid batteries are easy to destroy - they must never be stored except at full-charge,
and should be regularly topped up in storage (every month is good). Over-discharge also ruins them.

If your lead-acid battery has been neglected it would account for the behaviour.