It's always gratifying to pull back a wind-up toy and see it whizz off across the floor. But it's even more gratifying to build one yourself. Even better, a simple wind-up toy mechanism can be constructed from a few odds and ends you can find around the house. This same mechanism can be installed into a whole range of toys, meaning you can build whatever takes your fancy.
Drill a hole fractionally wider than the metal rod through the side of the wooden box. Drill another hole exactly opposite. Position the holes a quarter of the way from one end of the box.
Cut a 2-inch length of the square wooden dowel. Drill a hole lengthwise through its center just wider than the metal rod. Place in the box between the two holes.
Slide the metal rod into the hole in the side of the box. Force it through the length of dowel and out through the hole in the box on the other side. Check that the rod can turn freely.
Staple the end of the rubber band to the inside of the box. Staple to the end opposite the length of dowel and staple the other end to the dowel.
Use this mechanism as the basis for the toy you want to build. For a windmill simply cut a circle of cork mat and stick onto the end of the metal rod. Cut some fins from balsa wood and stick them on the edge of the cork. Twist the fins and release to set the toy spinning. For a toy car add an extra rod through the front of the box and stick a circle of cork onto the ends of the two rods.