The breathtaking development of electronic components is one key factor in the fast evolution of mobile robots. Depending on the mission, robots might operate autonomously or in cooperation with a human operator. In either case the locomotion of the robot is a key element. In general, legged systems are more flexible compared to wheel based systems and can be deployed in impractical terrain. Quadruped locomotion has the particular advantage to feature static as well as dynamic walking. Compared to n > 4 legs quadruped motion can be very agile, which is impressively demonstrated by cheetahs being the fastest mammal runners. On the other hand, quadrupeds feature static walking, which is beneficial for large scale walking machines such as legged excavators. In this paper a static free-gait pattern for quadrupeds allowing interaction with a human operator is discussed. Since experiments with large scale walking machines are very expensive, a scaled prototype is presented. However, the scaled prototype differs from the original system in many details. To guarantee the portability of the free-gait algorithm, the scaled workspace of the feet of the walking machine is proposed as criterion.