Design, Fabrication and Testing of a Glider and Launcher: An Exercise in STEM Education

This paper describes the design, fabrication and testing of a glider-launcher system for effective demonstration of flight principles, specifically the concept of neutral point in a classroom environment. A re-configurable glider was fabricated using extruded polystyrene sheets(depron). The glider is designed such that its centre of gravity can easily be adjusted to achieve flight with varying stability. This is done by placing magnets in varying positions on the glider. A portable launcher is designed and fabricated with high stiffness springs which are used to deliver the energy needed to launch the glider. A carriage system is built and mounted on linear bearings which slide on two guide rails. A worm gear drive is fabricated to reduce the effort required to elongate the springs. A buckle joint is installed as a quick-release mechanism. "Momentum transfer on impact results in the glider launching off the carriage. Three design iterations were performed for both the glider as well as the launcher to satisfy the predetermined requirements and constraints. The two primary requirements were to obtain a range of 10 m and demonstrate the concept of neutral point. The resilience and repeatability of the glider-launcher system were increased in successive iterations. Repeatability experiments were carried out to quantify the performance of the launcher and achieve constant results in terms of flight trajectory and range. The system was demonstrated in a classroom as well. The trajectories of the glider will be experimentally tracked and visualised over multiple launches. These will indicate that the system can be utilised repeatedly to effectively explain the effect of position of the centre of gravity on longitudinal stability.