RAMPS 1.4 is short for RepRap Ard. Mega Shield. It is designed to fit the entire electronics needed for a RepRap in one small package for low cost. RAMPS 1.4 interfaces an Ard. Mega with its powerful platform and has plenty room for expansion. The modular design includes plug in stepper drivers and extruder control electronics on an Ard. MEGA shield for easy service, part replacement, upgrade-ability and expansion. Additionally, a number Ardulno expansion boards can be added to the system as long as the main RAMPS 1.4 board is kept to the top of the stack.