News: May 2021 - Current projects and developments

Things have gotten a little quieter here on at the moment. This was because I was working harder on developing a few new projects.

Unfortunately, accessing the website or creating new posts often suffers as a result. However, since the roughest plans have now been completed, this will soon change again. 🙂

Until then, I would like to give you a brief overview of the current projects in the following article.


Last year I presented “WinDIY”, a wind turbine that can largely be made from 3D printable parts. (You can find information about this here: WinDIY – The wind turbine from the 3D printer)

Relatively quickly after building the first prototype it became clear that I would build a new version. The design of the first WinDIY version worked in principle, but there was a need for optimization in some areas.

I now want to implement these optimizations with a completely new design. Not only the design of the wings is being revised. The 3D printed generator is also being completely redesigned. In addition, I also plan to simplify some of the somewhat complex mechanics. Ultimately, the structure should be lighter, the turbine should run more efficiently and also be somewhat more compact.

I was able to gain a few partners for the development phase and the construction of the first prototype, which I would like to briefly introduce below.


The magnets for the generator were given to me by provided free of charge. A generator is planned in whose rotor up to 40 neodymium magnets measuring 40x10x10mm can be installed in a Halbach array.

In order to simplify the mechanics of “WinDIY_2”, I use worm gears in various places. Unfortunately, the worms of these worm gears are very difficult to print on FDM 3D printers due to the overhangs.

To solve this problem I recently switched to a Mars 2 Pro SLA printer To fall back on. This can be used to print 3D components with a very high resolution and even with overhangs. You can see a first result in the video below.

Of course, to build a 3D printed wind turbine you need filament. 🙂

In this regard, I am pleased about the support of who support the development of WinDIY_2 with their filament and resin products.

In the first version of WinDIY I mostly made screw connections with encased nuts. This often made assembly even more complicated.

To make this a little easier, when building WinDIY_2 I will use threaded inserts that can be melted into the 3D printed component. The Company Ruthex supports me with the thread inserts provided.

At this point, thank you very much for your support, which makes the implementation of WinDIY_2 much easier. 🙂

First results

My first sub-project for building WinDIY is building a worm gear. Three of these are to be installed in the WinDIY hub in order to ultimately be able to adjust the angle of attack of the blades.

The problem was that the friction between the worm and the worm wheel was too great when both components were printed using the FDM process. The rough surfaces resulting from the process repeatedly became wedged, which ultimately led to the worm gear not functioning reliably and blocking. The snail was also very difficult to print on an FDM printer due to the overhangs.

Ultimately, the combination of FDM printed worm wheel and SLA printed worm turned out to be very suitable. You can see the result in the following video.

View of the test worm gear.

In the following picture comparison, the differences in the surface structure can be clearly seen. I think this example shows very well where the limits of the FDM printing process lie and what can be achieved in comparison with the higher print resolution of an SLA printer.

You can see a few more pictures of the structure and components in the following gallery.

3D printing of aluminum components

While I was working on a project and I don't want to reveal too much at the moment, I recently faced a problem with my 3D printer: It was simply too small to print the model.

At 276mm wide, the model simply didn't fit on the print bed of my 3D printer. Thanks to a cooperation with I was able to solve this problem.

I created the component for the first time using the rapid prototyping service from have manufactured. Thanks to the SLM process offered there, I had the component made of aluminum on my desk a few days later. You can see more information and pictures of the result in the following gallery and in the article 3D Printing –’s rapid prototyping service

The “Still Secret” Project

To implement my still secret project, I don't just need a 3D printed holder (see previous section). The electronics are of course housed on PCBs, which I have already finished and tested. Unfortunately, I'm still working on a problem with the ESPEasy framework, which is why I haven't been able to get the board into operation as desired.

In addition to a few WS2812 LEDs, the following components are also installed on the two-sided board

  • ESP32 Wrover-B
  • DS3232M RTC
  • USB-C connection incl. programming option
  • BME280 Climate Sensor
  • Micro SD card slot
  • TSL2591 Brightness sensor
  • MPR121 touch sensor for up to 12 touch electrodes
  • MAX98357 3W I2S DAC

The combination of micro SD card slot, MAX98357 I2S 3W amplifier and ESP32 opens up exciting possibilities. For example, MP3 files from the SD card or web radio stations streamed via WLAN can be played on a speaker using the MAX98357.

I got the circuit board from the circuit board manufacturer who made them available to me free of charge.


One of my other PCB projects is the “pxlBlck_multiPCB”. As the name suggests, this board is intended to be the heart of several planned pxlBlck variants. For this purpose, several components can be installed on the circuit board.

Similar to the previous board, these are the following components

  • ESP32 Wrover-B
  • DS3232M RTC
  • USB-C connection incl. programming option
  • BME280 Climate Sensor
  • Micro SD card slot
  • TSL2591 Brightness sensor
  • MPR121 touch sensor for up to 12 touch electrodes
  • MAX98357 3W I2S DAC
  • ADXL345 Accelerometer

There is also space on the front of the board for a 10×10 LED matrix made of SK6812 3535 LEDs.

Additional sensors can also be connected via the QWIIC connection.

Unfortunately, I'm also struggling with software problems with the software for this board. Now armed with a JTAG debugger, I'll soon get to the bottom of them. 🙂

I got the circuit board from the circuit board manufacturer who made it available to me free of charge. At this point, thank you again for the great service. 🙂


Another project is the ePaper_Display, which has been on my desk for a while. After I recently found a practical firmware that allows individual data to be shown on the display, I started building my own information center about the data from my SmartHome.

To do this, I created a 3D printed housing in which the 7.2″ ePaper display including battery and ESP32 can be installed. You can see the current status in the photos shown below.

You can find the firmware that I used for this at the following link:

I hope you enjoyed the little insight into my current projects. If you have any questions or suggestions, please feel free to contact me using the comment function. 🙂

Best regards


  1. Hello,

    Your projects are awesome as always!

    Because of the ESP32 with I2S -> can they also be used by a Squeezebox (Logitechmediaserver) as an audio renderer and thus expand an open source multiroom audio system?

  2. Thank you for sharing your epaper display, that's super cool. I've been looking for this exact software for a while.
    The only thing missing is a temperature forecast chart showing the next 2 days or something. I find the graph very useful. Currently I have an android tablet with a temp graph on it and I might have to replace it with this! Thanks!

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