At one point or another I have probably already mentioned that it was important to me to be able to control WinDIY safely and to be able to limit its speed in an emergency.
This is why I developed a mechanism which allows to adjust the angle of attack of the wings. So the wings can be adjusted to the current wind and rotation speed. In addition they can be turned out of the wind in strong winds.
In this way the speed and the load of WinDIY can be controlled.
I have written down some additional information here: https://hackaday.io/project/172328-windiy-hawt-wind-turbine/log/179105-windiys-hub-oh-my-god-mechanics
In the following article you will find the instructions to rebuild the mechanism for adjusting the wing’s angle of attack.
Inhalte
- 1 Safety instructions
- 2 Affiliate links / advertising links
- 3 Requirements
- 4 Collect needed parts
- 5 Mount the hub base on the axle
- 6 Mount the first wing slot
- 7 Attach lever and adjust correctly
- 8 Install guide ball bearing
- 9 Mount the remaining two blades to the hub
- 10 Attach the nut lock
- 11 Attach the “lever extender”
- 12 Attach the lever plate
- 13 Insert ball bearing at anchor point
- 14 Attach the stabilizing ring
- 15 Mount push rod
- 16 Fasten the cover
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. https://www.nerdiy.de/en/sicherheitshinweise/
Affiliate links / advertising links
The links to online shops listed here are so-called affiliate links. If you click on such an affiliate link and shop via this link, Nerdiy.de receives a commission from the online shop or provider concerned. The price doesn't change for you. If you do your purchases via these links, you will support Nerdiy.de in being able to offer further useful projects in the future. π
Requirements
Required tools:
Hot glue gun |
3D printer |
Allen key |
Pliers |
Spanner |
Cordless drill |
3mm drill bit |
Tweezers |
Required material:
In the following list you will find all parts you need to implement this item.
3x | pitchArm |
3x | pitchLever |
3x | pitchArmNutSecuring |
1x | hubBase |
1x | pitchLeverDisk |
1x | hubCover |
1x | hubBearingCap |
9x | 603ZZ Bearing |
2x | 606ZZ Bearing |
5x | M6 self-securing nut |
6x | M6 nut |
3x | M3x20 Cylinderhead screw |
3x | M3 self-securing nut |
15x | M3 nut |
3x | M3x30 Countersunk screw |
3x | M3x16 Countersunk screw |
6x | M3x40 Countersunk screw |
3x | Prepared wing slot |
1x | M6 Threaded rod 60cm long |
Collect needed parts
Before you can start building the hub and its mechanics, 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 material and tool list
The required STL files for printing can be found here: https://github.com/Nerdiyde/WinDIY/tree/master/hub
I have printed the parts with the following settings.
- Perimeter: 5
- Infill: 50%
The screws should preferably be made of stainless steel so that they do not rust through moisture.
Mount the hub base on the axle
First the hub base must be connected to the axle. This actually makes further assembly a bit more complicated. Unfortunately, this has to be done right at the beginning, because the screw holes which are used during the assembly are difficult to reach later on.

For this you first need the shown parts.
The axle, the hub base, 3x M3 nuts and 3x M3x50 countersunk screws.

In order for the screws to hold the axle in place, you must first insert an M3 nut into the axle as shown.

Depending on the print quality of your printer, you may have to “force” the nut to go into the correct position.

Then you can insert the remaining screws into the hub base and screw them into the axle with the nuts.
The axle should now be bolted to the hub base with three M3x50 countersunk screws.
Mount the first wing slot
The blades are not directly connected to the hub. First only the slots are connected to the hub. The wings can then be plugged into it later.

Now you can plug in the first wing slot.
You should have already prepared this wing slot during the construction of the wing.

The first securing of the wing consists of a self-locking M6 nut, which is screwed onto the M6x100 screw of the wing slot.

When screwed on, it should look like this.
The nut should be so tight that the wing slot cannot be moved in the direction of the screw. At the same time, it should of course still be possible to turn it.
Attach lever and adjust correctly
Now comes a somewhat critical step where you should work as precisely as possible. To be honest I am not really satisfied with the mounting of the lever on the M6x100 screw of the wing slot yet. This is because the lever is secured on the screw by clamping it between two nuts. Theoretically this should hold. Practically, it does too. However, it would be safer to put a split pin through the M6x100 screw. There is certainly room for future improvements. π

For correct adjustment of the lever you should now raise the hub base a bit higher. For example, I have placed it on two boxes.

The goal is that the trailing edge of the wing slot is at exactly the same height as the back of the hub base.

Once you have adjusted the wing slot correctly, you can now put the lever on the axle and on the M6 nut that was screwed on before. The nut should fit as close as possible to the ball bearing, but the whole wing slot should still be able to rotate freely.
As soon as the lever is correctly attached…

…you can temporarily secure its alignment in the hub base with an M3 screw (the screw is removed again later). (see picture)
Install guide ball bearing
In this step, the ball bearing is installed, which allows the push rod to adjust the wing’s angle of attack. Actually this step could have been done before the installation of the wing lever.
Mount the remaining two blades to the hub
After the ball bearing for guiding the push rod is mounted in the hub base, you can continue with the mounting of the remaining two wing slots. These are mounted in exactly the same way as the first wing slot.
Attach the nut lock
As already mentioned above, the levers for adjusting the wing’s angle of attack are clamped on the M6x100 screw of the respective wing slot. To prevent the inner nut from loosening afterwards (which would cause the lever to no longer have any effect on the rotation of the wing) you should urgently secure this nut against rotation.

Before you secure the nut, again make sure that the inner nut is tightened as tight as possible.
But of course the setting of the lever should not be changed.
So first check that the angle of the lever to the wing slot is correct and then tighten the nut as tight as possible.
” Tight as possible” here means so tight that you can’t get it tighter “by hand” using a wrench.

Now you need a M3x20 cylinder head screw, a M3 nut and the 3D printed plastic part to secure the lever.

Now you can also check that the levers have the correct angle to the wing slots.
If the wing slots are straight (as shown in the picture)β¦

…the levers should hit the stops of the hub base. So the angle of rotation of the wing slots is limited in one direction.
Attach the “lever extender”
(Btw: Sometimes not easy to find suitable names for the individual parts. π )
This section is about attaching the “lever extender” to the previously mounted levers. This is part of the mechanism which turns the back and forth movements of the push rod into a turning movement for the wing.
Attach the lever plate
Here comes the next important part for the mechanics to adjust the angle of attack: The “lever plate”.

If you now move the lever plate back and forth you should already notice that the wings can be adjusted according to the distance of the lever plate.
Insert ball bearing at anchor point
So far we have used a ball bearing which is intended to guide the push rod.
Now the ball bearing is mounted, via which the thrust movement of the push rod is transmitted to the lever plate.

You will need the ball bearing securing plate, a 606ZZ ball bearing, three M3x16 cylinder screws and three M3 nuts.

Now secure the ball bearing in its position by mounting the ball bearing securing plate including the three M3x16 cylinder head screws on the lever plate.
Attach the stabilizing ring
To give the hub base a little more stability a stabilizing ring is now mounted on the hub base.

To do this, screw the M3x40 screws into the nuts, which are inserted into the recesses on the bottom of the hub base.
Mount push rod
The push rod consists of a M6 threaded rod. It will later transfer the thrust movement generated by the pitch actuator to the mechanism in the hub.

At this point you need the previously prepared hub base including attachments as well as two self-locking M6 nuts and an M6 threaded rod.

Then pull the push rod back a little and screw the first self-locking nut onto the push rod as shown.
The nut is unfortunately not visible but is located in the socket wrench, which makes assembly much easier.

It is also helpful if you clamp the threaded rod in a cordless screwdriver as shown. So you can easily screw the threaded rod into the M6 nut.

To keep the push rod in the upper ball bearing you have to screw the other M6 nut onto the push rod as shown.
The push rod should now sit tight in the ball bearing.
Now it is time for a first test.
Fasten the cover
Last but not least the hub now gets a cover. This covers the mechanics and should protect them from moisture and rain. Additionally it makes the hub slightly more aerodynamic.
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. π
Fab
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. π
