I've added the lines coming outward from the center of each surface to the design of Landru's Companion Cube Upgrade. Hope you enjoy!

Printed in High Resolution on a Replicator 2 with no supports or rafts.

I had a problem with the printer "stepping" over in the 'y' axis in spots. I think this is caused by the slicing engine, so I recommend printing the cube rotated at an angle around the vertical axis.