The wheel-less active cord mechanism is suitable for moving on rough environment. In this paper, we introduce the new wheel-less active cord mechanism “ACM-R7”. ACM-R7 has dust and water proof property. The coupled drive mechanism is installed to the joint mechanism, which enlarge output torque and motion range of the joint angle. In addition, the new control method of Loop-Gait locomotion was also developed. The new loop shape “Serpenoid-oval” and the steering control method ware proposed. These control methods were implemented to ACM-R7. ACM-R7 was able to move speedy and freely on the ground with those control methods.