Mobile robotics is increasingly present in everyday life. We can find it more and more often in our homes, industry, medicine, for military and hobby use. The main building materials of mobile robots are polymers due to their good mechanical properties and low mass. Currently, there are increasing investments and development of 3D printers and additive production methods, which enables the production of complex parts. Additive manufacturing technologies enabled the development of other technologies to optimize mass and stiffness. More and more in the industry we can find components that have an optimized topology, but the new technology of generative design is becoming more present. It enables the creation of optimized structures from scratch, without the constructor's initial model, and after the proposed optimized parts, prototypes are made for further production. The designed mobile robot is made of polymer material ABS. It is moved by legs and has 8 rotational degrees of freedom. The legs are powered by eight NEMA17 electric motors. Robot components were optimized using generative design and topological optimization. By comparing these two methods, a construction with a lower mass was chosen to enable it to be started more easily. The robot's motors are controlled using a dasduino microcontroller, based on arduino, from a Croatian manufacturer Soldered.