Category: 3D Printing

3D printing and 3D modeling
Fronius Symo & WS2812

Fronius Symo & WS2812

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I have 36 solar panels on my roof and a Fronius Symo 10.0-3-M inverter for a bit more than a year and I really enjoy watching the statistics. Since the system also has a smart meter, I can see production but also power consumption. In order to make everyone at home aware of our energy production and consumption, I decided to build this:

Led bar graph for Fronius Symo

This is a led bar graph that displays our current power to the grid data. In case we produce more than we consume, the led will get green. If we buy energy from the grid, the leds turn red. The more leds are on, the more energy we import (or export). The data is refreshed every 3 seconds so you can watch the effect of turning devices on and off (e.g. oven, hair dryer, coffee machine, etc) pretty clearly. The game is to try to get as much green as possible and avoid red.

I 3d-printed the stand in PLA and the led covers in transparent PETG. I used Onshape to design everything. I had still a bunch of WS2812 from another project so I reused them:

WS2812

I ordered a few Wemos MINI D1 ESP32 from ebay.com. The ESP32 platform is great because you get WiFi and some neat processing power in a cheap and small device. Perfect for that project. Even though the GPIO are 3.3V, I didn’t encounter any problem with the WS2812 (powered from a VCC 5V pin). I also did not bother putting a capacitor to smooth voltage peaks since I only have 10 leds and the wires are short enough.

Wemos MINI D1 ESP32

I designed the stand so that I can directly use the micro USB connector to power the system:

Powered via micro USB

I wrote the code using VSCode and PlatformIO, my go-to development stack for small projects of this kind. My solar inverter has a JSON API. I already used that API for another project so it was pretty easy to get the required data. The ESP32 connect via WiFi to my IoT network and then to the inverter over HTTP. The data are polled every 3 seconds. I cannot get data much faster than this, probably due to HTTP download and JSON parsing times. I did not investigate this further since 3 seconds is good enough. I used the great FastLED to drive the WS2812. I added a few visual effects to make the thing look a bit nicer.

So far all the family really enjoy the device. I made a second one for my parents who have the same inverter. In case you want more information, feel free to contact me. I can provide STL files and code if needed.
Sofirn SC31 Pro & Anduril2

Sofirn SC31 Pro & Anduril2

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I started buying flashlights a few months back. I started with an Astrolux FT03 which comes with Narsil installed. Anduril is another widespread firmware for flashlights with more features than Narsil. There is even Anduril2 in the work and I decided to install this version on my FT03.

A few weeks later, I decided to buy another smaller flashlight. Looking at reviews, the Sofirn SC31 Pro sounded like a great choice for me. It comes with Anduril. Since I had Anduril2 on my FT03, I looked at how to flash it on the SC31 Pro.

I found this post which sounded promising. As you can see here, you can access the ATTiny85 when removing the button. However, things are very very tight. Still, I decided to give it a try.

I bought some pogo pins and 3d printed a support for them:

The resolution of my 3d printer is barely good enough to have something usable. But that did the trick. I glue the pogo pins with CA glue:

I then soldered wires to the pogo pins and installed the device on top of the ATTiny85. This was clearly the most critical part. My 3d print mount is not optimal and I had to hold it in place using the wires. I double checked visually that the pogo pins were not touching 2 pins and were more or less correctly placed.

I plugged in my USBasp and could successfully access the ATTiny85 with avrdude. Flashing Anduril2 was then just a matter of a minute.

Based on the comments I found on budgetlightforum.com, Sofirn is using the same configuration for all its flashlights so I used cfg-sofirn-sp36.h to compile the firmware.

After flashing, I disconnected the USBasp, put in the battery and tested that everything was fine. I now have both my flashlights on Anduril2.
Isopropyl alcohol helps removing PLA prints from your bed

Isopropyl alcohol helps removing PLA prints from your bed

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I use a Creality CR-10 Mini since a few years now and really enjoy it. I mainly print PLA, PETG and flexible materials. I like to use PETG for “mechanical” parts or objects that need to be left outside. I also like how PETG is not wrapping at all when printing. Still I’m often using PLA for toys or objects with many small details.

I’m mainly using Extrudr NX2 PLA because I like the matte finish and also the fact that it is FDA approved. I often print stuff for kids so I prefer to use an approved material. However, I have issue with this PLA. Either it doesn’t stick well to my bed (IKEA mirror tile) or it stick way too much. I already took parts of the glass with the print while trying to remove the object from the bed, forcing me to replace it.

Egg dispenser bunnies

I add that issue again recently while printing an egg dispenser bunny for my kids. Using a bed temperature of 45°C, the print did not stick well and the print wrapped a lot in the corners. With a bed temperature of 65°C, the print went well but I was not able to remove it from the bed, even after the bed cooled down to 15°C (I’m printing in my basement).

Googling around, I found a post on a forum (sorry, I don’t remember the source) in which a guy said that he uses a few drops of isopropyl alcohol to help removing PLA prints from his bed. I bought isopropyl alcohol when I started using my printer to clean my bed. Yet, I’m not using it very often because I rather use hair spray nowadays. Still, I tried a few drops of iospropyl alcohol around the print, made it go under the print by tilting the bed and… I instantly heard the print “detaching” from the bed. I managed to remove my print with no effort (and damage) this way.

Isopropyl alcohol

I’m very surprised that I had never heard of this trick before. I think it is definitely worth sharing. Give it a try and you will see. By the way, it looks like isopropyl alcohol does not affect PLA so this should not damage your precious print.