A commercial robot, HapticMaster was often used to estimate 3-dimensional (3-D) human upper limb mechanical impedance transfer function matrix (MITFM) stochastically in recent years. However, the robot hardware and control performances for the estimation were not investigated and reliability was shown with only multiple coherences. With extensive experimental study, it was found that estimation 3-D human upper limb MITFM in the frequency range of interest with HapticMaster could be difficult due to the limited hardware and the control performances of HapticMaster.