Method for producing a circular-cylindrical body which consists of plastic compound and which has at least one helical inner cavity running in its interior, comprising the following steps: - producing a circular-cylindrical body, which consists of plastic compound and which has at least one rectilinear inner cavity running in its interior, by means of an extrusion die, - discharging the circular-cylindrical body out of the extrusion die via a twisting section to a retaining and transporting device which is designed to retain and transport the circular-cylindrical body and which can be rotated about its longitudinal axis, - twisting the circular-cylindrical body on the twisting section to form the at least one helical inner cavity by rotating the retaining and transporting device with circular-cylindrical body held and transported therein, and - discharging the circular-cylindrical body, which has at least one helical inner cavity running in its interior out of the retaining and transporting device onto a set-down device, wherein - the retaining and transporting device, which can be rotated about its longitudinal axis, is controlled by two motors, of which one is a feed motor which controls the speed of the feed of the circular-cylindrical body in the rotatable retaining and transporting device, and the other is a rotary motor which, simultaneously to the circular-cylindrical body being fed in the longitudinal direction, controls the rotational speed of the retaining and transporting device which can be rotated about its longitudinal axis, characterized in that - the pressing-out speed of the circular-cylindrical body out of the extrusion die is measured by means of a speed sensor, and the diameter of the circular-cylindrical body discharged from the extrusion die is measured by means of a diameter sensor, - the feed speed and the rotational speed of the retaining and transporting device are set by a control unit which receives sensor signals (s1, s2) from the speed sensor and from the diameter sensor and then feeds control signals (st1, st2) to the feed motor and the rotary motor in order to set the feed speed and the rotational speed of the retaining and transporting device, - wherein the control unit harmonizes the sensor signals (s1, s2) fed thereto with predetermined desired pitch values which result from the transporting speed and the rotational speed of the retaining and transporting device. - producing a circular-cylindrical body, which consists of plastic compound and which has at least one rectilinear inner cavity running in its interior, by means of an extrusion die, - discharging the circular-cylindrical body out of the extrusion die via a twisting section to a retaining and transporting device which is designed to retain and transport the circular-cylindrical body and which can be rotated about its longitudinal axis, - twisting the circular-cylindrical body on the twisting section to form the at least one helical inner cavity by rotating the retaining and transporting device with circular-cylindrical body held and transported therein, and - discharging the circular-cylindrical body, which has at least one helical inner cavity running in its interior out of the retaining and transporting device onto a set-down device, wherein - the retaining and transporting device, which can be rotated about its longitudinal axis, is controlled by two motors, of which one is a feed motor which controls the speed of the feed of the circular-cylindrical body in the rotatable retaining and transporting device, and the other is a rotary motor which, simultaneously to the circular-cylindrical body being fed in the longitudinal direction, controls the rotational speed of the retaining and transporting device which can be rotated about its longitudinal axis, characterized in that - the pressing-out speed of the circular-cylindrical body out of the extrusion die is measured by means of a speed sensor, and the diameter of the circular-cylindrical body discharged from the extrusion die is measured by means of a diameter sensor, - the feed speed and the rotational speed of the retaining and transporting device are set by a control unit which receives sensor signals (s1, s2) from the speed sensor and from the diameter sensor and then feeds control signals (st1, st2) to the feed motor and the rotary motor in order to set the feed speed and the rotational speed of the retaining and transporting device, - wherein the control unit harmonizes the sensor signals (s1, s2) fed thereto with predetermined desired pitch values which result from the transporting speed and the rotational speed of the retaining and transporting device. - the pressing-out speed of the circular-cylindrical body out of the extrusion die is measured by means of a speed sensor, and the diameter of the circular-cylindrical body discharged from the extrusion die is measured by means of a diameter sensor, - the feed speed and the rotational speed of the retaining and transporting device are set by a control unit which receives sensor signals (s1, s2) from the speed sensor and from the diameter sensor and then feeds control signals (st1, st2) to the feed motor and the rotary motor in order to set the feed speed and the rotational speed of the retaining and transporting device, - wherein the control unit harmonizes the sensor signals (s1, s2) fed thereto with predetermined desired pitch values which result from the transporting speed and the rotational speed of the retaining and transporting device.