I'm in the process of building a DIY cnc machine. It already runs, but I noticed it has some interference problems (steppers act weird on occasions, the full graphic smart controller LCD has trouble displaying the contents), due to the noisy chinese spindle I'm using. To remedy this, I've read I should ground everything in a star-like topology.
The hardware consists of a 12V chinese PSU which connects to an Arduino Mega with Ramps 1.6 and 3 DRV8825 drivers. There is also a spindle controller, which generates the noise and doesn't have the ground symbol. I was told on another forum, that since it doesn't have an earth symbol, I should just tie the earth to one screw of the chassis. The PSU and the spindle controller are connected to an extension socket.
I'm using shielded cable to connect to the stepper motors from Ramps, but the cable is also not grounded yet (just found out it has to be).
Can somebody describe how does a star-like topology look in my case? I've also read, I should ground the motor drivers, but I can't seem to find anything on the internet regarding this.
The 12V PSU:
The spindle controller: