News: May 2021 – Current projects and developments

At the moment it has become a little quieter here on That was because I was working harder on developing a few new projects.

Unfortunately, caring for the website or creating new articles often suffers as a result. But 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 a wind turbine called "WinDIY", which can be largely made from 3D printable parts. (You can find information on this here: WinDIY – The wind turbine from the 3D printer)

Relatively quickly after building the first prototype, it became clear that I will build a new version. The construction 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. For this, not only the design of the wings is being revised. The 3D printed generator will also be completely redesigned. In addition, I plan to simplify part of the somewhat complex mechanics. Ultimately, the structure should be lighter, the turbine should run more efficiently and also be a little more compact.

For the development phase and the construction of the first prototype, I was able to win a couple of partners, whom I would like to introduce briefly below.


The magnets for the generator were provided to me free of charge by The planned generator shall hold up to 40 neodymium magnets with the dimensions 40x10x10mm which can be installed in a Halbach array.

To simplify the mechanics of "WinDIY_2", I use worm gears at various points. 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 have recently been able to use a Mars 2 Pro SLA printer from With this, 3D components can be printed with a very high resolution and also with overhangs. You can see a first result in the video and pictures below.

Of course, filament is required to build a 3D printed wind turbine. 🙂

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 made screw connections mostly with set nuts. This often made assembly even more complicated.

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

At this point, thank you very much for the support, which considerably simplifies the implementation of WinDIY_2. 🙂

First results

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

The problem with this 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 got wedged again and again, which ultimately led to the worm gear not functioning reliably and blocking. The overhangs also made it very difficult to print the worm on an FDM printer.

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 seen again quite well. I think this example shows very well where the limits of the FDM printing process are and what you can achieve in comparison with the higher print resolution of an SLA printer.

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

3D printing of aluminum components

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

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

To do this, I had the component manufactured for the first time using's rapid prototyping service. 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 – The rapid prototyping service of

The "still secret" project

To implement my still secret project, I don't just need a 3D printed bracket (see previous section). The electronics for this are of course housed on PCBs which I have already been able to finish and test. Unfortunately, I am still working on a problem with the ESPEasy framework, which is why I have not yet been able to put the board into operation as desired.

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

  • ESP32 Wrover-B
  • DS3232M RTC
  • USB-C connector including 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 here. For example, MP3 files from the SD card or web radio stations streamed via WiFi can be played on a loudspeaker via the MAX98357.

I had the circuit board manufactured by the circuit board manufacturer, who made it available to me free of charge.


One of my other PCB projects is the "pxlBlck_multiPCB". As the name suggests, this board will 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 connector including 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

In addition, 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 am also struggling with software problems with the software for this board. Armed with a JTAG debugger, I'll soon get to the bottom of them. 🙂

I had the circuit board manufactured by 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 with which individual data can be shown on the display, I have started to set up my own information center about the data of my SmartHome.

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

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

I hope you enjoyed the little insight into my current projects. If you have any questions or suggestions, 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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