I've printed some dice towers for friends for playing D&D, and I wanted to make myself one that would make them glare with envy, as well as shake their heads in jealousy (or disgust, it's hard to tell). The Dice Catapult has accomplished this task with gusto. I always get comments like:

"Really man?"
"That is ridiculous."
"Wouldn't it be faster to just roll them?"

Clearly, they love it.

Anyway, on to the important stuff. The base, arm, and pin are all required for the dice catapult to function. The trigger is completely optional, but I highly recommend printing it so you can have the tower locked and loaded for quick firing of your dice. Every once in a while, my lighter dice will fly over the back wall, but I just beam with pride at the sheer power of my invention when that happens.

Speaking of that - you can adjust the power of the catapult by moving your rubber band to different notches on the base. You can also add multiple rubber bands to increase the power, but I can't recommend this.

Top notch - top notch power. This will launch single dice very fast, likely over the back wall. I only recommend using this if you're always rolling 5 or more dice. This setting may have been a mistake, but no going back now, right?

Middle notch - the perfect balance. This will handle single dice or loads of them admirably.

Bottom notch - like your granny throwing a baseball. This will slowly roll one or two dice, but any more and you'll find the arm doesn't really function.

I also recommend adding a rubber band to the top notch that doesn't connect to the arm, to slow the arm down when it throws the dice. This will keep it from slamming into the walls of the base and breaking either part. The pictures show the setup I'm using for this.

Once it is all set up with rubber bands, all you have to do is push the arm down, and the trigger should lock onto it and hold it down. Pressing down on the trigger will fire the dice.

Have fun, and for the love of everything, do NOT fire this at people.

https://www.youtube.com/watch?v=cnCTpdZ2NnA