Get your bottle and cut it 1/4th of the way down from the cap, this is around the area where the tapering from the top ends and the bottles full cylindrical shape begins. Keep the bottle cap screwed on and discard the lower half of the bottle and, with a pen, mark off six points around the rim of the end of the upper half. Cut upwards from these points, keeping your cuts an inch or so away from the bottle cap. Completely slice away every alternate strip and you are left with what looks like the head and blades of a fan.
For the next step, take a little precaution as it involves a naked flame and melted plastic can cause severe burns. Lightly brush the ends of the blades, the area near the bottle cap, with the flame to melt the plastic and give the blade an angle like traditional fan blades. This will also help to stiffen the plastic. Trim the edges of the blades to a more circular shape, but this is an optional step.
Now take your motor which already has leads attached to it and, after creating a hole large enough for the spoke of the motor, fit the bottle cap into the spoke and glue it in place. Keep the entire set up aside for now and take the thermocol boards, cutting one long strip for the stalk of the fan and a broad flat base. Glue the two together and then glue the motor and fan set up to the top of the stalk. Attach the black lead from the motor to one of the red wires of the switch. The other switch wire would be attached to one of the battery receptors and the red wire from the motor to the other battery receptor.
Now when you flip the switch, the motor should run causing the fan blades to spin. The speed of the rotation would depend on the power of your motor and the strength of your battery. This is a safe experiment which even children can enjoy making!!!