Calculate the resultant unbalance and balancing mass:

There are respectively three masses, 3 kg, 1 kg & 4 kg at radii 100 mm, 175 mm and 50 mm, as illustrated in the Figure 6. Calculate the resultant unbalance and thereby measure the balancing mass at radius 500 mm and angle where it must be mounted from the mass of 3 kg.

 Solution

 This example may be done analytically with graphically. To solve out the problem systematically a table may be formed as illustrated below :

θ= tan ^{- 1} - 76.25/176.25  = - 23.5^o

∴             Balancing mass = 192/500  = 0.384 kg

and angle for mounting =- 23.5 + 180 = 156.5^o .