I'm using a single plate of 1/4 inch 6061 as the flat base and some 6061 uprights at the front and back MIG welded in place with a top brace to form large box sections. These front and back side parts are great for attaching the large wheel suspension assembly to the robot.

Around the computer bay I have layed up some kevlar reinforced carbon fibre. I chose that over alloy to keep the weight down.

The battery bay is a thin alloy plate attached over the computer bay. I intend to bend some round steel stock and weld up a roll cage with metal mesh to protect the batteries from impact.

I have wired the RC receiver to an arduino nano which converts the RC PWM/PPM messages for a 10 channel remote into csv serial data. This keeps the code on the arduino simple at the expense of parsing csv data in a ROS node on the main computer.