Compounding system for dosing a compound in a container comprising a first Luer coupling end defining a first coupling axis (Af), and comprising a first thread having a first screw thread end, and a first pitch; wherein the compounding system comprises: - a Luer coupling holder for holding a second Luer coupling end defining a second coupling axis (As), and comprising a second screw thread having a second thread end, and a second pitch, wherein the first Luer coupling end and the second Luer coupling end are shaped to couple for forming a Luer coupling, and wherein the first thread and the second thread engage for establishing the Luer coupling; - a container holder for holding the container, wherein the Luer coupling holder and the container holder are arranged for aligning the first coupling axis and the second coupling axis; - a rotation actuator for rotating the container holder relative to the Luer coupling holder substantially around the first coupling axis; - a translation actuator for translating the container holder relative to the Luer coupling holder along the first coupling axis; - bias means arranged for biasing the first Luer coupling end and the second Luer coupling end when in contact in a direction of the first coupling axis; - a position sensor for sensing a container holder position of the container holder relative to the Luer coupling holder along the first coupling axis; and - a controller configured for: receiving the container holder position from the position sensor; activating the translation actuator such that the two Luer coupling ends contact and the bias means are biased; activating the rotation actuator when the first Luer coupling end and the second Luer coupling end contact in a non-engaging rotational direction; detecting a rotational position of the first thread end relative to the second thread end based on a sudden change of the container holder position; and controlling the rotation actuator, and the translation actuator for bringing the first Luer coupling end and the second Luer coupling end into engagement for establishing the Luer coupling. - a Luer coupling holder for holding a second Luer coupling end defining a second coupling axis (As), and comprising a second screw thread having a second thread end, and a second pitch, wherein the first Luer coupling end and the second Luer coupling end are shaped to couple for forming a Luer coupling, and wherein the first thread and the second thread engage for establishing the Luer coupling; - a container holder for holding the container, wherein the Luer coupling holder and the container holder are arranged for aligning the first coupling axis and the second coupling axis; - a rotation actuator for rotating the container holder relative to the Luer coupling holder substantially around the first coupling axis; - a translation actuator for translating the container holder relative to the Luer coupling holder along the first coupling axis; - bias means arranged for biasing the first Luer coupling end and the second Luer coupling end when in contact in a direction of the first coupling axis; - a position sensor for sensing a container holder position of the container holder relative to the Luer coupling holder along the first coupling axis; and - a controller configured for: receiving the container holder position from the position sensor; activating the translation actuator such that the two Luer coupling ends contact and the bias means are biased; activating the rotation actuator when the first Luer coupling end and the second Luer coupling end contact in a non-engaging rotational direction; detecting a rotational position of the first thread end relative to the second thread end based on a sudden change of the container holder position; and controlling the rotation actuator, and the translation actuator for bringing the first Luer coupling end and the second Luer coupling end into engagement for establishing the Luer coupling. receiving the container holder position from the position sensor; activating the translation actuator such that the two Luer coupling ends contact and the bias means are biased; activating the rotation actuator when the first Luer coupling end and the second Luer coupling end contact in a non-engaging rotational direction; detecting a rotational position of the first thread end relative to the second thread end based on a sudden change of the container holder position; and controlling the rotation actuator, and the translation actuator for bringing the first Luer coupling end and the second Luer coupling end into engagement for establishing the Luer coupling.