norelem supports the construction of a catapult

Five mechanical engineering students from the Baden-Württemberg Cooperative State University were faced with the task of designing and building a catapult with which an ordinary glass marble can be launched with pinpoint accuracy. The prototype had to be no larger than 50 x 50 x 50 cm and have a trigger mechanism similar to that of a crossbow: First, a component is cocked and then released “at the touch of a button”.

To ensure that the glass marbles hit the target, norelem supported the project with some components. First, the catapult was aligned on the floor with levelling feet. Indexing plunger serve to securely fix the catapult at the desired horizontal and vertical angle. Thrust washers ensure low friction in the turning mechanism.

As soon as the motor is running, the first of the toothed pulleys with toothed belt drives the second pulley. This causes the threaded spindle to rotate, which in turn moves the clamping plate attached to the spindle towards the motor. In the process, the clamping plate pulls the marble slide on the carriage backwards until the slide has passed over the release mechanism. The pressure spring prevents the slide from escaping upwards. When the carriage moves back, the catapult is tensioned. The spring is released with the trigger, the marble slide shoots forward on the profile guide rail and bounces against the stop plate, which is fastened with two shoulder screws.

The marble is fired, and if all calculations and settings are correct, the FOCUS team also hits the target in the project: at least three out of four shots should land in a defined target circle between 4 m and 24 m away from the catapult.