For swivel the mechanism of the stand, reformative rotary movement of a crank in back and forth motion scale-beams with tested caterpillar tapes, is resulted a technique of caterpillar modelling on a computer dynamic loading his bearings with construction of polar diagrams of reactions. For three variants of circuits of the counterbalanced mechanisms (with a flywheel on a crank) results of modelling as polar diagrams loading bearings are shown. The best results are given with the circuit with a flywheel on a crank and with counterbalance on scale-beam and a crank.