Introducing 3DPWPE - a 3D Printed Windmill Producing Electricity

Introduction:

Here you can find the printed parts to build a very simple and easy wind mill. This windmill produces electricity and is capable to output about 1W, 5V (enough to charge a mobile phone!).

Why is this project cool/something special?

You may ask yourself: Why is this project so cool? There are many answers. One answer is that this project is pretty useful, you could charge for example a battery pack, your phone or just show of your awesome 3D printing skills. :) Another point is the simplicity of this project. It doesn't use an expensive Nema Stepper or has complicated gear ratios. It uses a cheap standard electric motor and a rubber band as a transistion. This makes it a very cheap weekend project (<5$).

Design goals:

This project was designed using Solidworks. I always kept the simplicity in mind so that 3D printing beginners can also build it. One design goal was the easy printability. The parts don't need support at all and can be printed on a standard Makerbot Replicator 5th Gen. Another goal was to ban all the complicated and expensive parts (Stepper Motor, gear transition). I also focused on the looks of the windmill. You wanna put it in your garden so it should look cool right?! :)

How it works:

The wind blows on the blades of the windmill. Because the blades are angled (35° works good) the blades "want to escape". They can only "escape" by turning around the axis, so they turn around. This rotation is pretty slow. Because of this there is a bigger pulley and a smaller pulley. The bigger pully is fastened on the rotor axis, the smaller one on the generator axis. Between the pulleys runs a rubber band. The rubber band and the pulleys create the transition, so the generator turns faster than the rotor. The generator now transforms the rotation energy into electricity. You can use the electricity for every purpose you want.

How much does this project cost to make?

I thought a lot and came to the conclusion that I wanted to keep the cost as low as possible. Therefore I didn't use an expensive Stepper Motor as a generator. Because of this you need under 5$ to make this project!

Changelog:

23 of June 2015

• added the basic files of the frame

25 of June 2015

• added pictures of the CAD assembly
• added a Solidworks assembly file
• added the rest of the files, construction work of prototype "3DPWPE V1" is done
• design is being tested at the moment

29 of June 2015

• writeup is done
• I tested the design, works very good

Any questions?

Simply drop a comment or write me a message, if you have questions! Always happy to help! :)

You will need:

Printed parts:

• cover.STL x2 (optional)
• gear1.STL x1
• sidepart1.STL x1
• sidepart2.STL x1
• topbottomx2.STL x2
• axisstop.STL x2
• rotor.STL x1
• rotorspacer.STL x1
• propellor.STL x4

Non printed parts:

• 180mm 2.9mm rod
• a 23.3mm diameter electric motor
• some M3 20 screws
• wires
• an electronic circuit of your choice (what will you power with the electricity generated :)!?)

Suggested print settings:

• Extrusion widh: 0.48mm
• Layer height: 0.2mm
• Infill percentage: 30-40% (the higher, the better)
• Print speed: 30-100mm/s (depending on your printer)
• Support: off

Assembly instructions:

Before you start:

If you don't know how to execute a step look at the pictures of the assembly. They will help you!

Printing the parts/cleaning the parts:

Print the parts. You can use the settings recommended below. You should drill out the hole on the sidepart1.STL and sidepart2.STL with a 4mm drill to smooth the surface, so there will be very little friction.

Pressfitting the pulley:

Take your gear1.STL and one axisstop.STL and press fit them on the rod. Move them to the middle of the rod.

Pressfitting the generator:

Get your generator-motor and the sidepart1.STL and press the generator in the hole it is supposed to go in. Don't hesitate to use some force.

Assembling the outer case:

Get your rubber band and lay it over the gear1.STL. Then take both sides and put those sides over the axis so that the gear1.STL and the axisstop.STL is between them. Use the top parts and 4 M3 screws to fasten the sides together.

Finishing the trasition:

Take the end of the rubber band and put it over both pulleys.

Pressfitting the rotor:

This part is very tricky. Be very careful and have patience. Use a hammer to carefully tab the end of the axis first trough rotorspacer.STL then in rotor.STL. You can now use the second axisstop.STL to cover up the other end of the axis.

Final assembly:

Move everything on the axis like shown in the pictures in the gallery. Use a drop of super glue to hold everything nice and firm on the rod. You can also now put the four propellor.STL in the rotor.STL and align them (35° works very good). If you want to, you can use the cover.STL to cover up the big gaps, just remove the 4 M3 screws and put the cover.STL between the screws and the assembly.

What will you power?

You can now power your circuit with your fancy new windmill or can directly solder it to some LEDs or other interesting stuff.

Enjoy!