Hi fellow arduino people,
I am making a 3-axis CNC milling machine using an Arduino Mega2560. I am using 3 bipolar stepper motors (Nema 17) for the axis movement. I am planning on using Grbl to control the motors. Do I need to have a Grbl Shield?? or can I just use the stepper controllers that I already have made using an LK239 dual H-bridge? Also I can't quite figure out how to upload the Grbl software to the arduino, as I can't use the arduino sketch program.