Introduction: Windmill - 3D Printed, Laser Cut

About: We are a Middle School Design Studio at the International School of Brussel. Aiming at sparking creativity and innovation through design.

Hey there - If you have an easy access to a laser cutter and a 3D printer, this project will allow you to build a small wind turbine in less than 45'. A simple DC motor was used to generate electricity. The stand for the motor was made with a laser cutter using an MDF board. To connect the blades to the motor, we designed a connecting piece on TinkerCad which was later 3D printed. Blades were designed entirely by students using paper and skewers.

We designed this project to illustrate energy conversion to our 8th graders. It was an excellent starting point for a debate on renewable energies and the difficulty of generating adequate power.

Step 1: Material and Tools

Here is the list of materials and tools used for one turbine.

Material :

- 2 sheets of thick paper (Steinbach paper)
- 4 wooden sticks (skewers), which we cut in two
- 3 rubber bands
- 3mm thick MDF board for the stand.
- Regular DC motor (the one we used was 1.5V to 3V, 1.6W, 0.85 A )
- A connecting piece to attach the blades to the DC motor. We 3D printed a connector we designed (the stl. file is attached).
- a weight to counter-balance your windmill and prevent it from falling.

Tools :
- Scissors for cutting the papers for the blades
- Cutting clamp to cut the sharp edge of BBQ sticks
- Hot glue guns (superglue should work too)
- A multimeter and 2 cables with crocodile clamp to measure the current generated

Step 2: Building the Stand

Once you have laser cut the three pieces needed for the stand, you can glue them together. We glued first pieces 1 and 2 together. Then, we glued piece 3 to it.

Step 3: Designing the Blades

For the blades, feel free to try any kind of shape, material, inclination, ...

In our experiment, 8 short curved blades which we slightly angled inwards gave the better outcome (the fastest motor rotation speed). This being said, 3 or 4 bigger blades might work well too !

To achieve our configuration, we cut each wooden stick in 2 using the cutting clamp. The sharp ends of the skewers were cut as well to prevent any harm. Using the Steinbach paper, we made a total of eight 7cmx12cm rectangles. Each paper was then folded in two and a cut skewer was then glued in the middle of the fold. The two folds of each rectangles were glued together and cut according to the picture design. Once the blades were finished, they were inserted in the 3D printed connecting piece. A spot of glue was sometimes added at the end of the sticks to secure the connection.

Step 4: Connecting Each Part

Now, the windmill was close to done !

The DC motor was attached to the stand with 3 rubber bands as shown on the picture. It was then inserted into the 3D printed connector (with its attached blades).

At this stage your windmill is done! One last word of caution: since it is made to stand at the edge of a table, you should secure it with a heavy mass.

Using a regular fan to provide wind, you can then connect your DC motor to a multi-meter to see how much current and voltage it can produce. Our wind turbine was able to produce a current of 100 mA and a voltage of 350 mV. The model on the video reached up 190 mV.