This is part of the series of 30 exercises developed during the 3D4KIDS program. One of the aims of this Erasmus+ program is to improve the knowledge of teachers regarding the 3d printing technology by developing some specific training materials. More info in the website: https://www.3d4kids.eu/ This unit is about Materials and Electricity. Students will work in a collaborative way by means of the project-based learning methodology. They will have to design, draw and build a vehicle using some waste materials (soap bottle for the bodywork, caps for the wheels…) and electrical components (motor, wire, battery…). This vehicle will be driven by a 3, 5 or 7 bladed propeller 3D printed, that will be screwed to join the motor throughout a standardized bottle cap.