Archive for March, 2010
The handle is a piece of wood about 2×2 centimeter and 30 cm long. We cut an extra piece of the same material about 5-7 cm long and nailed that to one end of the handle, use also a little glue. The large nail is a roofing nail about 5 cm long, but you can use any smooth carpentry nail, not the rough twisted one though! You would like to have as little friction as possible from the nail/axle.
The hub is just a piece of old broomstick, but it can also be a piece of square wood. You need to cut two slots into it on opposite sides and at an angle for the blades to be put in, see photos below.
The blades are in our case cut from a old poster, the material is a plastic bristol board, but you can use any stiff cardboard or other material, such as an old plastic venetian blind. Look around the house or go to a print shop, or a curtain shop and they might be able to give you some suitable material.

The handle or base of the windmill is assembled with the small piece of wood glued in place and set firm with two small nails. Note also the large roofing nail and the two pieces of plastic straw that will act as washers.
The large steel roofing nail or you can also use any smooth carpentry nail, will fit in the hole in the small block and you can drive it with a hammer deeper into the wood of the handle so that it locks firmly in place. We have pre-cut a hole that is a littel smaller than the shaft of the nail into the wood block so it won’t split. This seems to work well for us.

The blades have been cut from stiff plastic poster material or bristol board, and the hub has tow slots cut into the side at an angle and at opposite sides, that accept the blades.
The hub is a piece of broomstick, but it can also be a square piece of wood. We made a cut with a narrow sawblade in two opposite sides. The cuts must be at an angle to give the blades a pitch like the blades from a propellor. You might need a little help from an older friend or family member. Put a little wood or paper glue on the cut before you slide the blade into the cut.

The two blades are put into the hub, a large roofing nail or other steel nail is used as axle, and two pieces of a plastic straw keep the blades away from the base and make them run easily, without too much friction.
Carefully look at the hub, it has the two slots cut in with a narrow saw blade, we use a saw for cutting steel, this has the right thickness. If you find that the cut is too wide for the blade material, just put a piece of folded paper in the slot with some glue then slide the blade in. Note also that the cuts are made at an angle with respect to the axle so that the baldes get the right PITCH!


