Hi Backers & Friends
Just wanted to give you a quick update on what we've been up to this February. Here are the highlights:
- We set a new wind speed record during storm "Otto," successfully testing our turbine under extreme wind conditions. Our turbine cut out automatically and remained stable in the strong winds, proving its resilience and ability to withstand tough conditions.
- We added more power stations to our supported list and were happy to see no issues with delivering power to them. We're working on testing with Goal Zero stations.
- We invested significant effort in improving the design of our turbine to enhance its ease of assembly and user experience. We redesigned the motor bracket and made the string tensioner stronger, resulting in fewer bolts and reduced assembly time.
- We faced issues with the strength of our parts due to various faults with our filament, but we're working on solutions to ensure the quality of our 3D printed components.
- We implemented additional software protection features to protect the turbine from unexpected faults. We should have testing efforts completed and verified by 9-10th March.
Thanks for your continued support! Now let's dive a little deeper:
New wind speed record!
During storm "Otto," we were able to successfully test our turbine under extreme wind conditions. Our test site at DTU Risø recorded gusts of 29.6 m/s at hub height, the highest ever measured at the site. Despite the challenging weather, the turbine performed flawlessly, automatically cutting out and remaining stable in the strong winds. It even automatically started again and continued producing when the windspeed reduced again.
We are proud of our turbine's resilience and confident in its ability to withstand even the toughest conditions.
Adding even more power stations to the supported list
We have been busy making arrangements to test more portable power stations. This isn't necessarily that easy since the portable power station market in Denmark is not that developed yet. We managed to find a webshop in Aalborg https://www.kikkert-teleskophuset.dk/ (the other end of Denmark), which allowed us to test their product. We also received support from the Nordic distributor of Ecoflow products. We tested 8 new power stations and all of them worked without issues. This gives confidence that it will work with most stations!
So far we have tested the following stations:
|Ecoflow||River 600 Max||Yes|
|Ecoflow||River 2 Pro||Yes|
|Ecoflow||River 2 Max||Yes|
Up on the list is getting hold of the Goal Zero stations. We've not yet had an opportunity to test with any Goal Zero stations. But that will hopefully soon come.
We have tried with one Chinese grid tie inverter (like this one), which didn't work. The change in internal resistance is too fast/violent for our ground station to behave properly. The grid tie automatically shuts resets.
Production improvements on several parts
We have invested a significant amount of effort in improving the design of our turbine, with a particular emphasis on enhancing its ease of assembly, tolerance to incoming part variation and user experience. Our team has meticulously reviewed all of the parts of the turbine, examining their printability and tolerances, and making small tweaks and modifications to around 66% of them. We have thoroughly tested the revised design and are currently running a turbine with all of the modifications.
While we won't delve into every single detail, we'll highlight the two most significant changes:
Redesigned motor bracket: We have redesigned the motor bracket to improve its stiffness and prevent the belt from getting loose during shipping. This change has allowed us to consolidate two separate parts into one, resulting in fewer bolts and reduced assembly time. The tensioning process of the belt has also been decoupled and made much easier.
Stronger string tensioner: We have beefed up the string tensioner to enhance its strength, and also made it possible to install it in multiple positions (previously only one angle was possible; now it can be installed at around 270 degrees).
Overall, our focus for this iteration has been to make the turbine easier to manufacture and reduce the likelihood of mistakes, while also making the user experience more robust. We are confident that these changes will significantly improve the performance and usability of our turbine.
Filament troubles - and solutions
As we mentioned in our previous update, we have been facing issues with the strength of our parts due to various faults with our filament. Despite the challenges, we are continuing to investigate the different factors that impact the strength of our parts, and are exploring potential solutions to improve the quality of our prints.
Causes: Unfortunately, we have experienced almost every imaginable fault with a specific supplier of filament. We have received filament that is too humid, has a varying diameter, is too small in diameter, and even includes large blobs that can clog our printer. As a worst-case scenario, we may need to switch to non-recycled plastic until our supplier is able to improve their product, or we find a new supplier who can meet our specifications.
Solutions: We are making several changes to improve our 3D print quality. We are in the process of setting up a climate-controlled chamber that will regulate the temperature and humidity levels of our filament storage area. We hope that this will help us maintain the quality of our filament and prevent further issues with our prints.
We have developed further methods to verify and control part quality that we would like to keep for ourselves for now.
We remain committed to finding the best possible solutions to these challenges, and are confident that our efforts will help us deliver high-quality, reliable parts for our customers.
Adding more software protection features
After the stepper motor angle sensor failures on two (inhouse test) turbines last month we've gone through a safety and fault causes/mitigation loop.
We've implemented a lot of additional features that will protect the turbine, even when there is unexpected faults.
The faults will now get sent to the app, with information on it, and also a button to clear faults.
We're almost done with testing all the features and ensuring everything works as expected. We should have the remaining testing efforts completed and verified during next week ~ 9-10th of March.
*NOTES: Pitch oscillations mitigation from last time, encoder failure.
The most vulnerable aspects: ground anchoring
In our last update, we mentioned a ground anchor failure that was caused by very wet soil. We have seen a picture of the anchoring from one of first users that conceded us. We have realised that our ground anchoring is now one of the most vulnerable part of our design, and it is crucial that users ensure that they have enough holding force in their anchors.
To address these challenges, we have been experimenting with different ways of testing the anchors. Our current method involves pulling on the straps, but people tend to pull with different forces. Based on our tests, most people can pull around 70-80kg (165lbs), which should be enough to ensure that even wet soil will not give way.
We are also developing a tool that can provide user feedback when pulled on, but we are still in the experimental phase and cannot share too many details at this time. The idea is to give users this tool so they can calibrate themselves on how much force the anchors need during the first few times they set up the turbine.
As a reference point, we have found that our anchors can hold over 200kg (440lbs) of force in normal grass-lawn soil. The expected force at peak load on the turbine is around 35 kg (80 lbs), and we recommend that users test their set-up to ensure that it can withstand 70-80 kg (165 lbs) giving a safety factor of 2. This will help to ensure safe and reliable operation of the turbine.
Deliveries - almost ready for a bigger sending:
We now have 8 turbines on the shelves that are waiting for the next firmware upgrade (safety features) before we will ship them out. These features can be installed later, but we prefer to ship them with updates included.
We are still prioritising backers that are eager to receive their turbine and have the opportunity to give us feedback. We are still looking for a few more, so please contact us at email@example.com if you help us out.
That's all for now!
Good winds to you all
The KiteX Team