Motor A not working

I am building a CNC machine using an Arduino Uno and Grbl. I have two motors for the vertical axis so motor a is a clone of Z. When I tried to test it A was not moving. I started troubleshooting and noticed that if motor Y is not connected motor A and Z work both fine. I already verified the Vref for the drivers and even replaced the shield, but nothing changed. Has anyone else have this issue? What did you do?

How are the drivers connected to the Uno? Are you using a CNC shield? If so, how are the jumpers connected? Can you post a photo?

I am using a shield with the jumpers to clone Z axis to A axis. I am including a photo

Do you have a DMM?
What is your power supply?

Thanks.. Tom.. :smiley: :+1: :coffee: :australia:


I am using a regular power adapter that provides 12V and 2A

Vref tells nothing. It depends on the value of the current sensing resistor.
What Amps are You trying to run in the motors?
2 Amps looks like too little.

Hi everyone

I have an update. So I am using two different kinds of drivers, 2 A4988 and 2 drv8825. I was using A4988 on motor Z and drv8825 on motor A. it just ocured to me to chage both to drv8825 and use the other drivers on motors X and Y. And it is now working.
I am very new at this and there is probably something very obvious that I am missing. I guess it was a bad Idea to mix drivers, but that is what I had.
Anyway, I am just happy it works and wanted to let you know, thanks for all the sugestions

This topic was automatically closed 180 days after the last reply. New replies are no longer allowed.