HowTo: WinDIY – Assemble the Wind Turbine’s Wings

An important component of WinDIY are certainly the wings. They absorb the energy of the wind and convert it into a rotary motion, which in turn feeds the generator and thus produces energy.

Of course, the wings should be as light as possible. At the same time, however, they should be stable enough to withstand the forces even in stronger winds.

On the way to a suitable design I have therefore experimented a little bit. Information about these experiments can be found here:

In the following article you will find the tips to rebuild the wing. You will (of course) need three copies of this wing.

Safety instructions

I know the following hints are always a bit annoying and seem unnecessary. But unfortunately, many people who knew it "better" from carelessness lost their eyes, fingers or other things or hurt themselves. In comparison, a loss of data is almost not worth mentioning, but even these can be really annoying. Therefore, please take five minutes to read the safety instructions. Even the coolest project is worth no injury or other annoyance.

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Required tools:

Hot glue gun
3D printer
Allen key
Cordless drill
(long) 3mm drill bit

Required material:

In the following list you will find all parts you need to implement this item.

You need the materials listed here for one wing. So make sure you order enough parts for three wings. 🙂

1xAluminum rod 10x10mm 67cm long
1xShrink tubing approx. 1 m long and 140 mm wide
1xM6x100mm hexagon screw
1xM6 self-locking nut
5xM3 nut
3xM3x20 cylinder head screw
2xM3x8 cylinder head screw
2xM5x75 cylinder head screw

Information about the structure

The wing design is based on the NACA4412 profile with a chord length of 120mm.

On the following page you will find information and configurable templates for this and other wing profiles:

Collect needed parts

Before you can start building the wing, you will of course need to have all the necessary parts together. A complete list of the required materials and tools can be found above in the materials and tools list.

The plastic parts can be easily created with a 3D printer. All parts are designed to be printed on a standard FMD printer.

The required STL files for printing can be found here:

I have printed the parts with the following settings.


  • Perimeter: 3
  • Infill: 10%

Wing base (both parts):

  • Perimeter: 5
  • Infill: 50%


  • Perimeter: 3
  • Infill: 30%

The screws in the wing should preferably be made of stainless steel so that they do not rust from moisture.

Mount the end piece

Somewhat untypically we start with the end. Namely the end part of the wing.

For this you need the shown parts.

Now insert the aluminium profile into the wing’s end part.

This should be pushed into the wing’s end part up to the stop.

Because now you have to drill a hole in the aluminium profile.

Therefore, use the wing’s end part as a template. By drilling through the hole (which is actually intended for the screw) in the aluminum profile, you will have the correct position for the drill hole.

Important: When drilling, make sure that you only drill through one side of the aluminum profile. You should not drill completely through!

Once drilled, your aluminum profile should look something like this.

Now the prepared aluminium profile must be connected to the wing’s end part. To do this, insert an M3 screw into the wing’s end part as shown.

This should then project into the recess for the aluminum profile as shown.

Now it gets a bit tricky.

Through the opening, into which the aluminium profile will later be inserted into the wing’s end part, you must now screw an M3 nut onto the M3 screw previously inserted.

The finished M3 nut could then look something like this.

Now you can insert the aluminium profile into the wing’s end part as shown. Screw it with the prepared screw.

Mount the first five rafters

After the wing’s end part is mounted, you can now mount the first five rafters on the wing.

Slide the first four rafters onto the aluminium profile as shown.

Now you have to prepare the fifth rafter.

This is fixed to the aluminium profile with a screw – similar to the wing’s end part.

Therefore, insert the M3 screw into the hole in the rafter and screw the M3 nut on the inside as shown.

You can then pull the M3 nut into the recess in the rafter using the screw.

Prepared like this you can now push the fifth rafter loosely onto the aluminium profile.

Before the individual rafters are pushed together, you should apply some glue to the connectors.

This is not absolutely necessary, since the wing parts will most likely stick together without glue. But I recommend it. 🙂

Coat the positioning aid on the …

…wing’s trailing edge …

… of every single rafter…

… and on the front of the wing with a small drop of glue.

If you have prepared all rafters with the glue…

…you can now put them together.

View of the first rafters put together.

Close-up view of the hole at the front edge of the rafters into which the positioning aid must be inserted.

Close-up view of the hole at the rear edge of the rafters into which the positioning aid must be inserted.

Now, prepare the fifth rafter so that the nut on the screw is pulled into the recess in the rafter.

Then you can slide the rafter onto the aluminium profile.

As soon as you have put the first five rafters together, you can screw the fifth (previously prepared with the screw) rafter onto the aluminium profile with the screw.

Make sure that the screw is tight but not too tight.

Mount the rafters six to ten

Rafters six to ten are installed basically in the same way as the previous five rafters.

You now need another five rafters.

You can slide four of them onto the aluminium profile as usual.

The fifth one should be prepared with a screw as shown before. With this screw you can secure the fifth rafter on the aluminium profile as shown before.

All five prepared rafters would then look like this.

Now you can coat the connectors with some glue like before and…

… put the individual rafters together.

When everything is put together properly you can tighten the screw of the last rafter and secure the attached rafters.

Mount the rafters eleven to 15

Meanwhile you already have practice in installing more rafters. Now you have to install the last five rafters before you can install the wing’s connector.

Here you can see the wing built up to now and the five rafters not yet installed.

Additional view.

Prepare the fifth rafter again as before so that you can fix it later with a screw on the aluminium profile.

Now push the five rafters back onto the aluminum profile, prepare the plug connections with glue…

…and push the rafters or their connectors together.

With the help of the screw in the last rafter you again can secure the rafters on the aluminium profile.

Assemble the wing-side part of the wing base

So that the wing can be easily assembled or disassembled later, you can now mount the first part of the connector on the aluminium profile.

For this you need the upper part of the connector as shown and a M3 screw including nut.

As with the wing’s end part you now have to put the upper part of the connector onto the aluminium profile and drill through the screw hole of the connector with a 3mm drill bit.

The aim is to drill a hole in one side of the aluminium profile (as with the wing end part).

Once you have drilled the hole, you can now reinsert the screw into the connector.

This should look something like this.

Now you can push the connector onto the aluminium profile and clamp it with the prepared screw on the aluminium profile.

Now the wing looks almost finished.

Mount the hub-side part of the wing

Of course, it must be possible to plug in the connector just mounted somewhere. Therefore you should now prepare the hub-side part of the wing connector. This will be mounted on the hub later when the hub is assembled.

Now you need the shown parts.

Additional view.

Now push the M6x100 screw as shown…

…into the connector…

…and place the self-locking M6 nut on the M6x100 screw as shown.

Screwed on ready…

…it should look like this.

Make sure that the head of the M6x100 screw is correctly inserted into the recess provided for it.

Now you can test the connector for the first time.

The parts should fit into each other as shown.

You can now secure the plug connection with the M5 screw.

Put it completely through the two parts of the connector…

… and screw it with the appropriate M5 nut in such a way that the connector is held together by the M5 screw.

Fasten the screw on the upper and…

…lower side of the wing.

Additional view.

Now the structure for your wing is ready. The only thing missing is the wing surface.

Additional view.

Additional view.

Prepare shrinking of the shrink tubing

In order for the wing to offer resistance to the wind and for its aerodynamic shape to generate lift, it is important that the skeleton of the wing is covered with a foil. The easiest way to do this is to place the wing in an appropriately sized shrink tube.

Dazu benötigt Ihr die abgebildeten Teile.

Important: Of course you should now remove the lower part of the connector. It should not be enclosed by the shrink tube.

Additional view.

Now check again that the shrinking tube is at least as long as the whole wing.

If yes, you can now insert the wing into the heat shrink tube.

Since you have to use hot air to shrink the shrink tube onto the wing, you should now store the wing slightly away from the base.

This way you avoid that the base is damaged by the hot air.

This could look like this, for example.

I simply used two empty boxes.

Close-up view of the wing in heat shrink tube.

Close-up view of the wing in heat shrink tube.

Close-up view of the wing in heat shrink tube.

Close-up view of the wing in heat shrink tube.

Close-up view of the wing in heat shrink tube.

Shrink the middle part of the wing

To shrink the heat shrink tube you need some patience. Here you have to be careful that the tube does not get too hot, because then holes will appear. In the video below you can see how I did it. To shrink the heat shrink tube I used a hot air station which I set to 150°C.

The aim of shrinking the shrink tubing is to ensure that it lies evenly and as far as possible without wrinkles on the wing skeleton.

Important: During this shrinking process you should not shrink the ends of the wing yet! In the next step these are prepared with glue to “seal” them.

A few tips:

  • never direct the hot air to one spot for too long
  • set the temperature not too hot
  • if in doubt, let the affected area cool down first and work on it again later

Shrink the ends of the heat shrink tubing

The ends of your wing must now be prepared with glue. This way the ends can be secured against water penetration.

This is what your wing should look like now. The heat shrink tubing is mostly tightly fitted to the skeleton of the wing.

The ends are still loose and not shrunk.

View of the loose (not shrunk) wing tip.

View of the loose (not shrunk) wing tip.

View of the loose (not shrunk) wing tip.

View of the loose (not shrunk) wing tip.

The aim is to seal the ends against water penetration. For this purpose you should now coat the space between the wing frame and the shrink tube with glue.

Especially in the corners a cotton swab can be helpful. In this way the applied adhesive can be better distributed.

You should do the same at the other end of the wing.

Make sure that the glue is spread around the complete wing.

When the shrink tube is shrunk later, it automatically lays on the wing and thus comes into contact with the adhesive over a large area.

In the following again two videos how I proceeded with shrinking the wingtips.


If everything went well, your wing should now be fully assembled. For a complete assembly you obviously need three wings.

View of the mounted wings on WinDIY

Have fun with the project

I hope everything worked as described. If not or you have any other questions or suggestions, please let me know in the comments. Also, ideas for new projects are always welcome. 🙂

P.S. Many of these projects - especially the hardware projects - cost a lot of time and money. Of course I do this because I enjoy it, but if you appreciate it that I share these information with you, I would be happy about a small donation to the coffee box. 🙂

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  1. Hallo,
    ein sehr interessantes Projekt, werde es weiter verfolgen, eventuell auch selber versuchen.
    Habe aber noch nicht alles gelesen.
    Eventuell habe gibt es eine Alternative zu dem verwendeten Schrumpfschlauch,
    bei unseren Modellflugzeugen verwenden wir Bügelfolie um die Tragflächen und auch die Rümpfe zu bespannen. Die Bügelfolie ist auf der Unterseite mit einem Heißkleber beschichtet. Die Bügelfolie wird mit einem Bügeleisen auf das Bauteil aufgebracht, der Heißkleber wird dabei aktiv. Eventuelle Falten, oder lose Bügelfolie wird durch schrumpfen dann stramm. Ich weiß nur leider nicht ob der Heißkleber auf dem Kunststoff hält. Aber ein Versuch ist es bestimmt wert. Einfach mal Bügelfolie Modellflug oder Modellbau googlen.
    Gruß Reimund

    1. Hallo Reimund,
      vielen Dank 🙂
      Das klingt auch nach einer coolen Option. Weißt du welche Temperaturen da bei dem Bügelvorgang entstehen?
      3D Drucker Filament wird (je nach Filament) ab ca. 70°C weich. Es gibt auch Filamente die etwas Temperaturstabiler sind.
      Ich hab auch bei der Konstruktion noch etwas Sorgen, dass bzw. ob der Flügel auch wirklich Wasserdicht ist. Ich hatte zwar versucht die Enden zu verkleben, aber ob das wirklich (dauerhaft) funktioniert müsste man mal mithilfe eines Langzeittests prüfen.
      Wie wird das denn bei Modellflugzeugen mit den Flügelenden gemacht? Werden die auch mit dieser Folie verklebt?
      Danke für den Hinweis 🙂
      Beste Grüße

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