For questions specifically related to the RAMPS 1.6 controller board - The RepRap Arduino Mega Pololu Shield, or RAMPS for short, is an expansion shield for the Arduino Mega designed to fit the entire electronics for a RepRap 3D printer in a small, low cost package.

The RepRap Arduino Mega Pololu Shield, or RAMPS for short, is an expansion shield for the Arduino Mega designed to fit the entire electronics for a RepRap 3D printer in a small, low cost package.

New with version 1.4 is the usage of surface mounted capacitors and resistors to increase the coverage of edge case issues. Also, unlike version 1.3, version 1.4 is no longer suited for easy home circuit etching.

Additional information and a full list of features can be found at the RAMPS RepRap Wiki page.