The internal diameter of the coil is determined by the external diameter of the coil axle, which can be altered freely and controlled by coder and electronic counter. The analog quantity of the length of the resistance wire can be set and adjust on the counter to achieve length control. When the wire comes to the preset length, the machine will cut it using the air cylinder or electromagnetic mechanism. The other counter of the machine records and controls the quantities of the helical coils. The frequency converter is for adjusting the rotation speed of the control coil axle.