The geometry of the locating part is shown in Fig. 9b. Similarly, according to Eq. (6), the mass of link 3, m3, can be redistributed to point D and point C as m3,1 and m3,2, respectively, and the mass of link 2, m2, is redistributed to point C and point B as m2,1 and m2,2,respectively. The following analyzes the balance condition and the balance error.