robot chassis 3d model

A 20cm by 20cm chasis of an advanced line follower robot. I want it to become only a one piece (for the components only, not the sensors). So here is the thing, the design features two n20 motors at both sides, and the microcontroller at the middle, its more like a rectangle(for the motors) with a triangle beside it(for the microcontroller). i wan tit to become as lightweight as possible,