For a new version see https://www.thingiverse.com/thing:4619514

This is a case to hold a DCC++ base station made from an Aurdino Uno and a motor shield. For more information on DCC++ visit http://www.trainboard.com/highball/index.php?threads/introducing-dcc-a-complete-open-source-dcc-station-and-interface.84800/

The picture shows the UNO version. I have not test printed the MEGA version.