Modified the vertex to slightly flare the bottom of the opening for the vertical extrusion to compensate for the way the first layer tends to squish and make it too tight.
Made lower frame 12mm taller to accommodate the fuse/plug/switch holder.
Modified the upper/lower frame to use M5x10 bolts instead of M5x12 ones.
Added license comments I noticed where they were missing.
Added comments in motor.scad, roundedBox.scad, and vertex.scad to clarify that those shouldn't be sliced -- they're only included by other files.