Project: Catapult Launch Angles

I have designed this project to be a practical way to demonstrate launching projectiles at fixed angles. The catapult has a stop pin that is adjustable in 5° increments from a 25° stop angle to a 90° stop angle. The throwing arm has a max tension indicator (stop). The indicator is there to assist in creating equal tension on every launch, so that students can compare what happens to the distance when we change the launch angle.
https://youtu.be/tsxN56f2HFo