When asking for technical help at the very least let us know the version of firmware you are running.Cliff's Calibration (Mapping) Guide is a MUST READ: http://www.vemssupport.com/forum/index.php/topic,97.0.html
The assembled ones come with strips of aluminim with threaded holes, the holes line up to the screw holes in the outside of the case, its a bit of a fiddle to get them in place but once its done its a good clamp.Make sure you use insulation sheet though.Rob