How to build a Catapult?

Catapult is a device used to throw an object over a long distance. It has been used since ancient times, it has proven to be one of the most effective mechanisms during warfare. It was designed to break or circumvent city walls and other fortifications in siege warfare.

Cost: Around $ 10

Objective: 

We should build it in such a way that, it hits its target with accuracy with bare minimum cost.

Things to consider:

Holder
Base
Trigger Mechanism

In my opinion, for a holder, you can choose a hole which is smaller than the ball which you are going to throw out. The base should be as large as possible because we need maximum friction below the base and for the trigger, you can choose any elastic tube, I have read somewhere about medical tubing which is good too.

Design:

As shown above, catapult would be build using plywood. Two similar shape plywood will work as an arm and would give support to it. H Shape shown above is used as a holder stopper.

Useful Links:

How Catapult works?

Catapult Project by Students


Build your own catapult using PVC Pipes

Hubpages article on building a small Catapult

Related Video :

Build your catapult