This is a 5 material cuboid that is half a cube high.

Using Slic3r I created a few different AMF files. These may be used to slice. One has an integrated perimeter that will help keep ooze strings off the finished surface. The other has the perimeter as a 6th object and you must set slic3r's settings to use an available extruder for that since the MH3000 can only have 5 extruders. The last file has no fence perimeter and so must rely on the slic3r ooze prevention option only.