Model originally uploaded to Thingiverse at https://www.thingiverse.com/thing:4912205.

This is a spool holder with a weight sensor included, it is based on a 2kg load, an HX711 board, and an Arduino nano, I made it basing on my CR10 v2 by creality but it can easily be fitted to other printers it will require:

⚫2 M5 screws ⚫6 M4 screws and 4 nuts ⚫The spool holding tube that comes with the 3d printer, if you don’t have it it’s a tube with a 3cm diameter you can easily print that but if needed I’ll make the model just ask for it. ⚫Load cell (it can have multiple values but I suggest going for the 2kg ones) ⚫HX711 board ⚫4 Digit seven segments digital display with TM1637 (that only has 4 pins, the dimensions are the ones in the link i add) ⚫Arduino Nano and USB cable to program it. ⚫Basic soldering skills ⚫Wires both with and without pins for arduino ⚫Optional: Step down converter 24/12V to 5V depending on the voltage of your 3d printer power supply, if you don’t use it get a wall adaptor and a severed usb cable ⚫Hot Glue gun (you can probably find an alternative tho) ⚫kitchen scale ⚫Optional: Either a empty spool or a full one (or just know the weight of a spool)

I think this can be a pretty cool Arduino project and it's pretty simple i found it pretty amusing i suggest understanding how it works too if you wanna get into this kind of stuff.

I've also made a pdf guide on how to assemble it and the ino file for the arduino script other than the 7 stl files. The total cost is pretty low if you go with Chinese websites for electronics but it's not that bad even with amazon even tho prices are high for electronics there. Note that the reading is acceptable only while not printing because of the tension of the filament.