Making the box out of mdf as its strong and relatively cheep, if not a little annoying at times. I used 12mm for the sides and 6mm for both bases. In the image below I’ve turned the movable base over and am measuring up for where to place the motors. It never surprises me how much bigger things are in reality rather than in the plans. I thought the walls would be much more shallow than this, but even at 32cm they are way bulkier to cary back on the tube.
Using an air power nail gun to join everything together was a good way keeping everything smooth and is a lot quicker than drilling holes.