Building a Small Wind Turbine: Building the Blade Hub

What You'll Need
Drill bits (7/32 inch, 1/4 inch, 5/16 inch)
Jigsaw with a metal blade
Pipe wrench
Flat head screwdriver
Crescent wrench
Vise and/or clamp
Wire strippers
Tape measure
Marker pen
1/4 inch #20 thread tapping set
Old or used saw blade, about 7 1/4 inches

This article is a part of a series of guides that will help you build a small wind turbine on your own. In this article, you will learn how to build the blade hub for your small wind turbine. The blade hub is where your blades will be attached. Below are the tools and materials needed for the small wind turbine, especially for building the hub. The steps to build the blade hub will follow.

Step 1 – Take off Hub from Treadmill motor

Some treadmill motors will come with a hub attached. If the treadmill you are using for this project comes with one, take it off. You will need something more appropriate for your small wind turbine. In this guide, an old and used saw blade will be used as the hub because it's solid and light. At the same time, a larger surface area will allow you to securely bolt the blades into the hub. Another alternative to an old saw blade would be an aluminum frying pan. In order to remove the old hub, hold one end of the motor shaft with the use of pliers. Now, turn the hub clockwise. The hub unscrews clockwise. Thus, when you see blades turning on a wind turbine, it turns counter-clockwise.

Step 2 – Create a Hub Template

Since you are replacing the original hub of your treadmill motor and building one from scratch, it's recommended to create a hub template. Using your piece of paper, a compass and protractor, make a circle from your paper. Mark 3 holes from the center of your circle. Make sure that it is 2 3/8 inches away from the center of the circle. It should also be equidistant from each other. Now, it's time to make use of the template.

Step 3 – Mark the Hub following the Template

Place the template on top of the saw blade and punch a starter hole through the paper and into your saw blade-turned hub. Do the same for all the holes. Now, using a 7/32 inch drill bit, drill holes through each of the starter holes you just made. This is now the correct hole size for your homemade hub.

Step 4 – Tap and Bolt the Blades

Using a 1/4 by 20 inch tap, tap the holes. After, start bolting the blades you've built earlier. The steps for making the blades can be found on a separate article. Make sure to use 1/4 inch bolts for your blades. At this point, the outer holes have not been drilled.

Step 5 – Make Outer Holes

Now that the inner hole of your blades have been bolted to the hub, arrange the blades so that they are equidistant to each other. Mark and punch each starter hole on the hub with the empty holes in each blade as your guide. Now you will need to remove the blades to drill the hub once more. But before you do so, mark your blades and your hub so that you know which blade will to which hole in your hub later on. You can mark it blade 1 and hub hole 1, blade 2 and hub hole 2, and so on.

Step 6 – Drill Outer Holes

Once you've labeled your blades and holes, remove the blades and drill the outer holes in the hub. Don't forget to tap before you bolt your blades back to the hub.