A counterweight-style catapult model. You can use the solid or perforated rods inside the model to fix the hanging basket and swing arm.

If you choose to use a punching rod to fix the position, you can do it by inserting a 1.75mm-diameter filament into the hole, and then heating and flattening the ends of the fixing rod to fix it in place.

In addition, you need to make a slingshot bag like in Figure 3 with a rope. One end of the rope is tied to the swing arm, and the other end is hung on the hook at the end of the swing arm.

Finally, add a counterweight to the hanging basket, and it's ready to be launched