The main axis is the axis in which the wind turbine will later rotate. It must therefore bear the weight of the blades including the hub and at the same time absorb the forces generated by the wind. Last but not least, it should rotate smoothly.
A critical task and in my opinion one of the most important components.
I have written down some additional information here: https://hackaday.io/project/172328/log/179713-why-i-think-a-new-main-shaft-mount-is-needed
In the following article you will find instructions on how to assemble the mounting of the main axis.
Inhalte
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/
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Requirements
Required tools:
Hot glue gun |
3D printer |
Allen key |
Pliers |
Cordless drill |
3mm drill bit |
tweezers |
Required material:
In the following list you will find all parts you need to implement this article.
1x | basePlateMainShaft |
1x | mainShaftBearingMountBaseConnector |
2x | mainShaftBearingMountBearingClamp |
1x | mainShaftBearingMount |
1x | shaftCoupler |
2x | Aluminum profile 14.5cm long |
2x | 6008ZZ ball bearing |
12x | M3x50 countersunk screws |
8x | M3x16 countersunk screws |
6x | M3x20 countersunk head screws |
Collect required parts
Before you can start building the main axis, of course you have to collect all needed parts. 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/mainAxis
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 ball bearing in the main axle base
The base of the main axis consists of one part. In this part the two ball bearings are inserted and clamped.

For this part of the main axle assembly you need the main axle base, two 6008ZZ ball bearings, four M3x20 screws and four M3 nuts.

Now check again that both ball bearings are seated up to the stop and centered in the main axis holder.

To secure the ball bearing in the main axis holder, you should now insert the first ball bearing clamp into the main axis holder as shown and…

In the same way you should now secure the other ball bearing with the ball bearing clamp in the main axle mount.
Connect the main axis base to the base connector
The main axis base is connected to the base plate using the base connector. To do this, the main axis base is now first connected to the Base Connector.

For this you need the shown parts.
- The prepared main axis mount
- The 3D printed basic connector
- Two 14,5cm long pieces of the 10x10mm aluminium profile
- Six M3x50 countersunk screws
- Six M3x20 countersunk screws
- Twelve M3 nuts

Now drill with a 3mm drill bit -through the hole provided for the screw- into the aluminum profile.
Important: Make sure that you only drill through one side of the aluminum profile. More about this in the following pictures.

To fasten the aluminium profile in the main axis holder you now need two M3x20 countersunk screws and two M3 nuts.

Now place the first of the two M3 nuts into the recess on the inside of the guideway for the aluminum profile as shown.

Now retract the screw including the nut so that the nut disappears completely into the matching recess. Now you can insert the aluminium profile and as soon as the holes in the aluminium profile are congruent with the screws, you can screw the screws into the holes of the aluminium profile.

Now screw the screws further into the aluminium profile until the aluminium profile is clamped by the screws in the holder.

Now drill through the screw hole in the aluminum profile as done before.
Important: Make sure that you only drill through one side of the aluminum profile. More about this in the following pictures.

Now pull the screw back again including the nut, so that the nut disappears completely in the matching recess. Now you can slide the base connector back onto the two aluminium profiles of the main axis bracket.

View of the attached basic connector and the main axis bracket.
The screws you have just prepared will be tightened in a later step.

This should sit in such a way that it can be screwed together with the previously inserted M3x50 countersunk screw.

Both screws should now be secured with one M3 nut each.

You can now use the two remaining M3x50 countersunk screws to connect the base connector in the same way on the bottom side.
To do this, push the screw through the base connector into the main axis holder as shown in the picture…
Connect the main axis holder to the base plate
The next step entails connecting the prepared main axis mount (including the base connector) to the base plate.

For this you need:
- of course the prepared main axis mount
- the 3D printed base plate
- four M3x50 countersunk screws
- four M3x20 countersunk screws
- eight M3 nuts

Now you need the remaining M3x50 countersunk screws.
Insert this too through the – still empty – screw holes in the base connector into the base plate…
Prepare connection with the pivot bearing
In the last step the base plate is prepared for the final connection with the pivot bearing.

For this you need:
- the prepared main axis mount including all attached components
- four M3x25 countersunk screws
- five M3 nuts
- the 3D printed connecting plate

Now it gets a little bit complicated. The connecting plate must now be placed on the base plate in such a way that the M3 nuts previously inserted are locked between the connecting plate and the base plate.
These are needed later to connect the upper support of the turret with the connecting plate.

Thanks to the M3x50 screws from the connection between the base connector and the base plate, the connecting plate is now already in the correct position.

Now you can screw the first two M3x25 countersunk screws through the connecting plate with the M3 nuts previously inserted in the base plate.

To do this, the last two M3x25 screws must be screwed back on the upper side of the base plate using an M3 nut each.
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. 🙂
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. 🙂
