Let’s explore how to design, build, program, and then play with our own 3D printed robot arms.Currently robot arms are expensive or small and weak, or clumpy. The arm operates with the help of 6 servo motors. Resources - Robotic Arm 3d model, USD $0. A Robotic Arm is a type of mechanical arm, usually programmable, with similar functions to a human arm the arm may be the sum total of the mechanism or may be part of a more complex robot. Robotic arm 3d model computer aided design computer aided design programs computer aided drafting engineering cad software free 3d cad models free 3d cad software free cad software download libre cad 3d linux 3d cad mechanical cad.