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 is composed of 10 independent pieces. The first two pieces (the two smallest) will be a quarter of a circle with 1 cm size radius, the third will have the same shape but 2 cm of radius, the fourth 3 cm, the fifth 5 cm, and so on by continuing the Fibonacci sequence (1, 1, 2, 3, 5, 8, 13, 21) up to the last piece with size 21 cm. The pieces that will compose the spiral are contained and supported by a rectangular back support, also printed in 3D and divided into two halves. This has a recess of 7.5mm to better allow the positioning of each piece.