So, For FIRST FRC robotics, We have made 3 different objectives to research, and I decides to start with the projectile. We need to launch an 8" diameter foam basketball into a goal that's 18" diameter. We can be anywhere from 3feet to 54 feet away. We had an idea of using the classic catapult style but then making the stopping point moveable to take the range calculations and compute them with a varying force of the arm. However, this can be very unreliable in a sense if we want to actually score. Now I've been researching but I just cannot determine this: would pneumatic pistons offer a more precise force with a calculated air pressure instead of a springy force that would be in the catapult that would deteriorate? As well, are there any other methods of launching this projectile up between 2' and 8'?