Hi, i saw such problem on my CNC router. Try to increase the power (to 24V). Maybe 12v is not enought. i changed my power supply to 48V. and also, the good decision - using different power supplies for steppers motors and for inverter.

I`m near Varese. If you want to come, please let me know(is possible to do it in usual working time, becouse we need to enter the fabric)

Hi, i`m from Italy) I bought 2 robots AR4. I still not coplete the post about it, but it will be a little bit later. First of the robots is working full day in factory. It is chainging items for CNC milling machine. If you need some help or you want to see how it works i will be glad to help you