It's helpful to place a small drill bit between the blades and through the center hole in the hub to get things centered up well. There should be a tiny flat spot on the center of each blade where they meet each other so that when they come together there is a hole in the center of it all big enough for a small drill bit to help make sure we get everything (the blades and hubs) centered perfectly.Ĭenter one of the Birch hubs over the blades and line up the screw holes you drilled over the blades.

angles accurately they should fit together fairly tightly.

Lay out the 3 blades with the flat sides (the side that will face into the wind) up as shown in the picture. Drill a small hole (About 3/16' is good) in the center of both hubs - this will make centering and alignment of the two hubs easy. Then countersink the holes so the screw heads will be flush with the top of the plywood. Use a compass to lay out neatly where the screws will be before you drill the holes. Divide the hubs into three parts and drill about 15 holes in the areas where the roots of the blades will be between them. Baltic Birch ply is rarely available from normal lumber yards, but you can find it at shops that sell more exotic woods for cabinet making and fine woodworking. Normal plywood will do if the Baltic Birch is difficult to find. Baltic Birch plywood is much stronger than normal plywood and holds up to weather well - we prefer to use it for the blade hubs. The blades for the 10' diameter wind turbine will be sandwiched between two plywood hubs, 11' in diameter. 11' diameter disk cut from 1/2' plywood (preferably Baltic Birch), qty 2 5/16 - 18tpi 3' long carriage bolts, qty 6 Some folks prefer to glue the blades/hubs togther - this design is such that you can disassemble the blade set should you ever need to replace parts. Some of this is optional, certain things could be done differently. Following is the list of materials and hardware required to assemble the blades. This next section will detail how we assemble them. At this point you've carved 3 nearly identical wind turbine blades.

Wind turbine blade template