This build was one of my most fun builds. I really enjoy building machanical devices on SP. This is a type of catapult and can launch the block a good distance. The arm IS NOT powered. The arm uses gravity to pull the weight on the other end of the arm. To make the arm swing, activate 1. There is a detacher that holds the arm in place till you activate 1. The arm will start swinging on its own. There is a detacher at the end with the projectile. It also separates when you activate 1, but it has a 1.3 second delay so it’s self launching. The detatcher IS NOT powered! Before you launch, the free swinging projectile arm is folded up to the middle of the trebuchet. This is because it acts as a sling that quickly launches the projectile. This is how real trebuchets work. After launching the arm will rock back and forth in a werid looking way because of the weight. There is no way of resetting the arm so you’ll have to reset the creation. Hope u guys like it! Happy Flying & Upvote For More!