Here is a simple electronics box for the Sanguinololu board (were all the connections actually fit inside the box). When I built my Huxley I had a perfect box for the electronics. This is a replication of that box. I am only using the lid myself after deciding that 10mm holes for ventilation would be enough to keep the stepper drivers cool. On the original lid I had a fan mounted. I had to split the box in half because my Huxley can only print 130X130mm. The box is 144x82mm and 29mm deep (outside measured). Walls about 2mm. The extra slit on the lid is for the SD-Card reader. That's the position I have my reader in. But you can of course move it around in SketchUp.

Print 2 of each part (lid and bottom) and use the "Joins" to snap the box parts together using the 10mm holes, then use 4 M3X40 screws and 4 M3 nuts to assemble the lid and the bottom parts together.