This is part of the series of 30 exercises developed during the E3D+VET program. The aim of this Erasmus+ program is the immersion in 3D printing of VET centres (website: ). The model consists of 14 independent pieces. In the round base is fixed a vertical and central rod on which are connected by 4 joints that allow the rotation two horizontal elements. On the horizontal elements, two vertical rods are fixed by means of connectors which have two circular plates at their upper ends.