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: 2 rectangular bases with central cavity where the pillars are fitted, 5 pairs of pillars - each pair with a different type of connection and 5 beams with different ends for the connections. The model has two functionalities: - Show the students some types of structural system connections between beams and columns and allow them to know the design of the connections as well as understand through the 3d model how each part of the structural system fits in the other part. - Allow the students to test in practice how the structural systems work and react to the pressure and compression, being able to analyse the result and differentiate each type of connection in the process.