Introduction
Building your own windmill from scrap materials can be a fun and rewarding project. Windmills harness the power of the wind to generate electricity or pump water. Constructing one yourself allows you to generate renewable energy and learn about engineering principles. I will walk you through the full process of gathering materials, designing, and constructing a scrap windmill from start to finish.
Gathering Materials
The first step is sourcing recycled, repurposed, or leftover materials to build the windmill. Here are some key components I used for my homemade windmill and where I found them:
- Blades - I used 3 thin wooden boards from old shipping pallets for the blades. Pallets are commonly left over behind stores. Make sure to sand them smooth.
- Motor - The motor turns the kinetic energy of the spinning blades into electricity. I salvaged a small DC electric motor from an old computer.
- Pole - This supports and elevates the windmill. I used a 5 foot long thick metal pole discarded from a construction site.
- Electrical - For generating electricity you need wire, an outlet, battery etc. I got scraps from a habitat for humanity reuse store.
- Bolts/nuts/washers - Necessary for assembling. Check your garage or hardware store for leftovers.
- Bearings - Allow the blades to spin freely. Scour junkyards or disassemble old machines for ball bearings.
Get creative searching scrap yards, garage sales, junk drawers, and behind stores for supplies. Building from all recycled materials reduces waste and cost.
Designing the Windmill
Once you have gathered adequate materials, next is designing the windmill itself. Factors to consider in the design:
- Height - Taller allows accessing faster wind speeds further off the ground. My 5 foot pole was a good starting height.
- Number of blades - More blades can increase efficiency but also weight and rotational resistance. I used 3 blades for simplicity.
- Blade pitch - The angle of the blades affects rotation speed. I angled mine about 30 degrees for sufficient torque.
- Blade length - Longer blades sweep a larger area but add weight. My 3 foot pallet wood blades spun up easily.
- Pivot direction - Blades should be angled to properly catch directional winds. I aligned my blades horizontal to prevailing winds.
Make sketches and notes to lay out a design fitting your specific materials and needs. Simplicity is best starting out.
Assembling the Frame and Blades
With a plan in place, it's time to construct the windmill frame and blade assembly:
Frame
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Lay the pole horizontally and attach the motor mount to the top end using nuts/bolts. Verify it is aligned properly.
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Attach the bearing set several inches below the motor to give room for blade clearance.
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Mount a second bearing set about halfway down the pole to reduce wobbling from wind forces.
Blades
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Cut 3 pieces of pallet wood into evenly sized blades - I made mine 3 feet long.
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Sand the wood smooth and shape the blades with a curved taper.
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Using bolts/nuts, attach the blades equally spaced to a circular plate at their center.
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Align the blade angle (pitch) properly to catch the wind based on your plan.
The frame and blades are now ready to be pieced together and raised.
Putting it All Together
The final assembly steps are:
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Mount the blade assembly onto the top bearing to allow spinning.
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Run electrical wires from the motor down through the pole. Leave access at the base to connect a battery.
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Carefully raise the pole vertically and anchor in place with guy wires attached to stakes in the ground.
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Connect the battery and multimeter to test power generation.
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Position the windmill to face into the prevailing winds. The blades should start spinning!
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Troubleshoot any issues with rotation or power generation. Check alignment and tighten bolts.
With proper assembly and placement, the scrap windmill should successfully harness wind energy. Start small and make improvements over time. Let your creativity guide you in designing and building a functional windmill completely from repurposed materials.
Conclusion
Constructing your own homemade windmill from scrap materials can be an enriching DIY project. Follow the steps outlined above for sourcing supplies, designing, assembling the frame and blades, and raising and testing your windmill. Consider how you can improve the design over time. With some creativity and persistence, you can build an electricity-generating windmill entirely from recycled parts, reducing waste and saving money while learning about engineering and renewable energy.