We use aluminum or steel for bodies of the robot. In this article I will examine the two materials. Aluminum Advantages Easy to work Light Disadvantages Not for welding, for welding some special systems needed (TIG welding). Aliminum Laser cutting is harder than other metals. Not resistant to big impacts. It can bend. Tapped holes can be easily stripped. Steel Advantages Hard Easily weld (It’s big advantage) Disadvantages Heavy Harder drilling when compared with aluminum.