Nowadays robotic-based surgery is most promising one in medical field. Since the Total Knee Replacement (TKR) and Total Hip Replacement (THR) are increasing in numbers therefore it is a need for using the robots in these types of surgeries. Also, more precise bone removal rate is required in TKR and THR to fix the implants; therefore robots are needed to incorporate to remove the bone precisely. Lot of existing systems are based on industrial manipulators and also having high cost. Hence, there is a need for exclusively designing a robot for orthopaedic-related surgery with low cost and also by analyzing all the parameters involved in bone removal. So, this paper aims to design an orthopaedic surgical robot arm manipulator. The modeling results are presented and it showed reasonable matched outcome with the phantom models. Also the results are showing an encouraging trend in furthering this research. © 2016 IEEE.