Your science project does not have to be complicated to be good. Even a simple machine will do the job. If you build a lever, pulley, inclined plane, wheel and axle, and wedge and make a working machine out of the combination it will be a fantastic science fair project. It will be simple to make as each of these does not take much effort.

It will also have the advantage of using multiple parts of simple machines to make a complex machine. Imagine the old Tom and Jerry cartoons where the mouse trap is so complicated looking. It is essentially a series of simple machines being used together for one single objective, that of a mouse trap. Of course its a different matter that the traps always end up back firing when clever little Jerry is involved.

Now think of a simple task that you would like performed. Decide how many steps it will take to perform the task. Now split up each step into a simple machine that you would like to do the action. Put it all together and attach the simple machines to each other so that there is a domino type of effect and viola you have a killer science fair project all set to go.