This catapult has a scientific background. It shows the effect on the range of a projectile, depending on the angle under which the projectile is fired. In this way the catapult can be optimized for the purpose. The base frame has a row of holes in which an M3 bolt can be pushed which will stop the lever. By using one of the other holes, the stopping angle is changed. The catapult is powered by two rubber bands. A trigger button is provided to make firing easier.
It is recommended to print with an infill of 100%. A 100% infill will make the structure stiffer and stronger. The parts fit on a table size of 20x20 cm. If your table is smaller, it is better to resize the parts than to rotate them. Rotating leads to weaker parts because of the absence of +/- 45 degree layers. The SCAD files are included to make it possible to make changes.