The LARMbot is a low-cost user-oriented humanoid robot designed for service purposes developed at the LARM2 laboratory in University of Rome Tor Vergata. This paper presents the new design of LARMBot v3 with the same overall size of previous version 2. The design problems of LARMbot v2 are discussed to identify the needs for improvement in structure and mechanism solutions mainly for more efficient operation in improved motion capabilities. The LARMbot v3 is designed with improved features mainly in torso design, arm mechanism structure, and a new full assembly solving flaws in the previous LARMbot v.2 version.