And it works fine, whatever the calibration error is, it's consistent.
So in reality, the finished part size might not be exactly that, but whatever the difference is, it is propagated to both parts. This probably wouldn't be true if I printed the parts separately in different printers.
Anyway, we're talking about tenths of millimeters.
I have a just tested a few wemos D1 mini pro from the Aliexpress/wemos store. They are top notch imho, you cannot find anything better for 5$ (of ESP8266 based boards). They are very small and come ready for stacking with extra boards. Fast shipping to...
@gohan Well, in my case, it is going to replace my thermostat, so I already have the 5 wire cable coming up from the basement for that which takes care of the hole in the wall. Since the main controller for the thermostat is in the basement, all I should need at the tablet side is a temp sensor. I will use the 5 wire cable to connect my 5 volt charger and probably a DS18B20 temp sensor to read the temp. In the basement, I will create an arduino node to read the temp and send it to the thermostat controller over my RS485 network. All the other thermostat controls will be handled by the tablet.
It was not so hard finding one. I got it from the Pi Hut because now and then they get a shipment and via their newsletter the word is spread. Actually, they seem to have it in stock right now. Just pick the "Just the Pi Zero" option to avoid all their extras