I’ve built this CNC machine (http://ift.tt/132ayVe) as high school major project, which is due very soon, and I was wondering how to convert it to a 3D printer.If I bought that hot end and extruder (http://ift.tt/29Rh3gJ), how do I connect it to the Arduino Uno? The spindle motor, currently attached to my CNC machine, has 2 terminals which is connected to a relay which is connected to pins 12 and GND on the Arduino, so it can be controlled through GRBL. But, the stepper motor for the extruder has 4 terminals, and requires a driver to run. Other tutorials use an Arduino Mega with a shield to combat this problem, but is there any way to connect it to the Arduino Uno instead? Please help me out, the project’s due very soon! http://ift.tt/29NDJyC