The Small Wind Turbine

Hey everyone,

​I'm really excited to share my latest project with you, and this one is a bit different. It’s inspired by a movie called The Boy Who Harnessed the Wind. When I watched the final scene, seeing the water finally gush out from that well, it honestly brought tears to my eyes. That moment hit me hard, and it was a major reason why I decided to become an engineer when I was in school ( 10th standard). Now, here I am, in my final year of my Bachelor of Technology degree, just 7 months away from finishing.

​So, I decided to build a working wind turbine to light a small LED, not just as a project, I have to make small light

The goal is to power a small LED light for the chickens at night. ​This might look like a simple project, but I’ll be showing you all the challenges and design choices I made along the way.

We'll talk about the parameters and the different considerations that went into making it all work. I hope that this project inspires others to look at the world around them and think about how they can use engineering to make a difference, just like the boy in the movie did. Here, I also use the scarab items to build the Wind turbine.

​Let's get started.

Materials

1. An old Xerox machine stepper motor with a gear (to be used as a generator)
2. 1mm PVC pipes
3. 2.5mm PVC pipe
4. 4-way junction box
5. Aluminium hollow rectangular bar
6. Thermocol sheet (for 4 blades, each approx. 70cm x 25cm)
7. Random wooden blocks (for support and fillets)
8. An old bicycle inner tube
9. A 6 ft steel rod
10. Bending wires

Electronic components

1. Diodes (1n4007) x 8
2. capacitor (25v, 3300uF) x 1
3. Vero board x 1
4. LED light (4watts) x1

Tools ️

1. Rotary tool kit with a cutting attachment
2. Pencil
3. Ruler
4. Quick glue
5. Nose pliers
6. Scissors
7. Gloves
8. Soldering kit

First thing I was creating the main hub for the blades. I took a piece of dia 20mm PVC pipe and cut four small, evenly spaced slits down one end.

I then gently heated the plastic until it was soft, which allowed me to bend and flatten those four sections outward. This created a solid, cross-shaped flange that would act as the mounting base. (<The photos of heating the pipes are unfortunately deleted >)

Once it cooled, I lined the new hub up with the gear and drilled four 2mm holes right through both the PVC flange and the gear.

The 2mm Bolts are placed in the PVC pipe

But the only tricky part was getting the nuts on the back; I had to pop the gear off from the base to get enough room to securely tighten the nuts and bolts with a screwdriver.

I made the main support arm for holding the shaft in place.

For this, I used a hollow rectangular aluminum bar, but to give it some real strength and a solid anchor point, I first slid a tight-fitting wooden block down the entire length of it.

The real trick was figuring out how to bolt it securely to the generator frame. I drilled a hole near the end of the aluminum bar, going through to the wood inside.

Then, from the open end of the bar, I carefully carved out a recess in the wood directly behind the hole, just deep enough for a nut to sit flush inside.

With the nut hidden inside the support arm, I could line it up with the generator frame.

Thread a bolt through from the outside. As I tighten the bolt, it pulls on the hidden nut, clamping the aluminum bar rigidly to the frame.

But it does not have enough strength, so then I drilled a hole beside the bolt and added a srew. This makes for a super sturdy support for the main blade shaft.

My next idea was an experiment, but it didn't work out❌.

I was worried that once the generator was electrically loaded, the blades might struggle to spin. My solution was to add a right-angled gearbox between the blade hub and the Generator Set.

I thought this would increase the torque and help the blades overcome the resistance. That plan turned out to be a bust. The gearbox slowed the rotation down way too much. Even when I spun the hub by hand as fast as I could, the output shaft was barely turning. the stepper is not generating much power ( average 1.9V) due to very low speed

It was clear that the wind would not have sufficient speed to effectively rotate the generator (stepper motor).

So, I removed the right-angled gearbox and went with a much simpler approach:

connecting the blade hub to the generator set (stepper motor + already included gears on base) with a straightforward extension shaft made from a piece of PVC pipe. I will show this process in the next step

the main rotating assembly is built around the 4-way junction box. I drilled a hole through its center and glued a piece of 20mm PVC pipe in place. This is the main shaft to spin.

To attach everything to the support arm, I used a larger, 25mm PVC pipe. This pipe serves as the outer mount to the shaft, and it's the part that I clamped tightly to the main support arm with the bicycle tube to hold it steady.

Reasons to use the wooden blocks.

First the entire shaft assembly is held perfectly straight, which prevents any binding or friction as it spins.

Second I realized that if it were angled even slightly, some of the other gears wouldn't mesh properly.

Once the pipe was sitting perfectly in its wooden block, I used the bicycle tube to clamp the whole thing down tightly.

This creates a really stable for smooth rotation and the outer mount for a rigid connection to the rest of the wind turbine.

To turn the pulsed electricity from the stepper motor into usable power, I built a simple conditioning circuit.

Dual Rectification

A stepper motor doesn't just have two wires; it has at least four, for its two separate internal coils (phases). Each coil produces its own AC-like signal when the motor spins. The key is to treat them independently.

I built two full-bridge rectifiers, one for each coil. Each rectifier uses four diodes to flip the negative half of the AC signal into a positive one.

Combining and Smoothing

With both coils producing their own pulsed DC, the next step was to combine them. I connected the outputs of the two bridge rectifiers in parallel, positive to positive and negative to negative.

This combined output still has a bit of pulsing. So, the final touch was to add a smoothing capacitor across the parallel output. The capacitor acts like a tiny, fast-acting reservoir, filling in the gaps between the pulses to create a much smoother and more stable DC voltage.

I soldered the AC inputs of the first bridge rectifier to one pair of the generator (stepper motor) terminals, then did the same for the second rectifier with the second pair of terminals. This links the raw power output to the conversion circuit.

This clean DC output connects to power a small load directly or to charge a battery by using an additional charge controller module.

The challenge was figuring out how to attach the soft foam to the round pipe securely without the connection points tearing through.

First, I pushed several U-shaped lengths of thin bending wire through the centerline of the foam blade.

The key part of this step was placing a small, firm sheet of material, acting as a washer, under the wire on the top side of the blade.

This simple addition spreads the clamping force and is crucial for preventing the thin wire from ripping through the foam under stress.

With the wire loops pushed through the foam, I laid the PVC pipe spine onto the back of the blade. Using a pair of pliers, I twisted the ends of each wire tightly around the pipe, cinching the foam and the pipe together.

As a final touch, I added a dab of glue to each twisted wire knot to make sure they couldn't loosen or slip along the pipe. ready to be mounted on the hub.

I made a last-minute improvement to the blades. I carefully carved and shaped the flat Thermocol surfaces to give them a slight cut, creating a more effective airfoil profile that should catch the wind better.

(Use the sketch as a reference, IMG(7.3))

Next, I attached these four finished blades to the junction-box hub. I set each one at a specific angle to the wind and then used a good amount of quick glue to lock them permanently into that position.

Finally, for the tower, I used a 6-feet steel rod. the complete generator assembly to the top and lash it tightly to the rod with a few loops of strong GI wire.

I observed that the supporting arm is bending along with the shaft, which creates friction, so I attached a wooden stick to give stable support.

Now for the real reason I built this whole thing. I've mounted the finished wind turbine on top of our agricultural greenhouse. A little ways off from there, we have a chicken shed, and that's the target.

The goal is to power a small LED light for the chickens at night. I’ve found that they can't see or fight back against predators in total darkness, so a bit of light should give them a fighting chance.

I'll eventually need to run a long wire out to the shed, but first things first, the immediate next step is to do a direct test and see if the wind turbine can actually power the bulb.

For the moment of truth, with the windmill installed and the wind blowing, it was time for the first real power test.

To see how it would handle different demands, I connected both an inductive load (a small toy motor) and a resistive load (an LED bulb) to the output. It's a good way to check the performance under different conditions.

The windmill powered both the motor and the light without any issue, performing exactly as I had hoped it would. When I buy the long wires from the windmill to the chicken shed, then I will install the LED in the shed, and a battery with a small charge controller.

I'm happy to say the result was a complete success.

Thanks for following along with the entire build. If you enjoyed seeing this and support more projects like it in the future, please consider subscribing to the channel.

And of course, if you have any questions or doubts about any of the steps, just ask in the comments below. I'll do my best to answer them.

THANK YOU!