This is a short-range catapult that was meant to be displayed on a desktop or other surface. It does work, but becase it was meant to be displayed, you need to push one end of the catapult to get it to shoot. This thing was made in OpenSCAD with the code below. If you enjoy, please like!
SCAD code:
difference()
{
union()
{
polyhedron(
points=[ [10,10,0],[10,-10,0],[-10,-10,0],[-10,10,0], // the four points at base
[0,0,10] ], // the apex point
triangles=[ [0,1,4],[1,2,4],[2,3,4],[3,0,4], // each triangle side
[1,0,3],[2,1,3] ] // two triangles for square base
);
translate([20,0,0])polyhedron(
points=[ [10,10,0],[10,-10,0],[-10,-10,0],[-10,10,0], // the four points at base
[0,0,10] ], // the apex point
triangles=[ [0,1,4],[1,2,4],[2,3,4],[3,0,4], // each triangle side
[1,0,3],[2,1,3] ] // two triangles for square base
);
translate([-10,-10,-20])cube([40,20,20]);
}
translate([0,-20,-15])cube([20,40,40]);
translate([-5,0,0])rotate([0,90,0])cylinder(30,2,2,$fn=100);
translate([-5,-2,0])cube([30,4,20]);
}
translate([40,20,-18])rotate([0,90,0])cylinder(30,2,2,$fn=100);
translate([55,30,-18])rotate([90,90,0])cylinder(41,2,2,$fn=100);
difference()
{
translate([55,-20,-18])sphere(10, $fn=100);
translate([45,-30,-15])cube([20,20,20]);
translate([55,-20,-18])sphere(9, $fn=100);
}
translate([20,-30,-19])sphere(9, $fn=100);

Supports are not neccisary, but rafts might be, depending on the 3D printer.