Four stations automatic balancing machine for dynamic balancing of small d.c. electric motors armatures. The machine is composed by a loading and unloading station, an initial unbalance measuring station, and unbalance compensation station by milling on two planes, and a station to check the residual unbalance. A manipulator with a four position rotating table carries the pieces from one station to the next station. The machine is designed in such a way to be integrated in totally automated production lines. A five station version is also available for high productivity requirements.