Useful Info for Building Catapults

What are some useful calculations and just info in general to build a successful and consistent catapult for VEX Starstruck?

step 1- dont
all jokes aside, a catapult is simply not needed for this game as more efficient ways to get stars over, i recommend the claw method as it can travel without needing to lift into the air, adn can deposit more than 3 stars if wished, however if your adamant on making a catapult, a 63 degree is optimal for last year, a slipgear can work, but i recommend a choo choo

I’d recommend visiting some other threads about catapults for Starstruck.

As much as I would like to dispute a catapult’s effectiveness with you here, I will send you a PM to keep this thread on topic. As to the most efficient design for a catapult, a slip gear has issues. But so does a choo-choo, tensioning and releasing one, and the design that 46644C’s XLR8 @LEER used that still needs a name. (Seriously we need to get on this we’ve been referring to it as the thing with the gears and the standoffs and the hooky thingy.)

To address your question about catapult calculations, as far as I know the only things you could want to know require a deep understanding of the physics behind it, and will get very very complicated very very quickly. One of the aspects of our catapult that we have been dealing with is getting the dimensions of it correct so that it is the most efficient. Before you build a pullback mechanism for it, play around with variables such as how long the catapult arm should be and how high up should the arm be mounted in order to achieve maximum efficiency for throwing.

Next, come up with what type of pull back and release mechanism you want. The main mechanisms that people use are: slip gear, XLR8’s unnamed thing, choo-choo, and a tensioner and release mechanism. Here are some examples: XLR8 Thing Slip Gear Tensioner and Release Choo-Choo

Now PLAN out your gearing. How do you want everything arranged? One of the biggest issues with a catapult is the load that the gearing needs to be able to pull back in order to launch these big heavy objects. You will struggle and struggle and struggle but don’t give up! You will face issues like breaking teeth off of gears, or your motors simply can’t handle your gearing and you have to redesign. But eventually, you will finish, and you will have a robot that is much more effective than any claw or dump bot there is. :smiley: