The assembly of the hollow shaft motor with the piston pump requires only few minutes. For a new customer we filmed this assembly using the pump that the client himself has paid. The motor hollow shaft has a turned diameter on its flange corresponding to the diameter of the pump's face on which it must be mounted. When ordering, the client must always indicate the pump the he will use in order to receive a motor with the correct flange and shaft. The motor-pump axial alignment is done by the flange diameter, NOT THROUGH THE FLANGE HOLES. The turned diameters of motor-flange and pump-flange must always be IDENTICAL. For a proper alignment is necessary that the motor flange is correctly fixed on the abutment of the pump's face and of the motor housing.