Coupling drag-is the use of a universal joint will be balancing machine spindle is connected with the rotor. Coupling characteristics of drag is suitable for irregular appearance of the rotor can deliver big torque, larger rotor drag for wind turbine, wind resistance, couplings drag disadvantage is the unbalance of the coupling itself will have an impact on the rotor (hence the coupling before using it to balance it), will also introduce disturbances affect the accuracy of the balance