Filament Holder W/Scale by dieki

Last crawled date: 3 years, 2 months ago

Filament holder w/integrated scale. Provides a live readout of filament weight remaining right in Octoprint.
Setup
You will need an HX711 breakout board and a compatible load cell. You can find these bundled together on Ebay/Aliexpress for less than $10. Any load cell rated for more than 1kg and less than 50kg should work; I used a 5kg load cell with solid results.
The load cell I used had tapped screw holes for M5 screws on one side and M4 screws on the other. It doesn't matter which direction you hook up the load cell. I used M3 screws w/t-nuts to connect the bracket to the frame of the printer.
See here for instructions on wiring up the load cell: https://tutorials-raspberrypi.com/digital-raspberry-pi-scale-weight-sensor-hx711/
You will also need this Octoprint plugin: https://github.com/dieki-n/Octoprint-Filament-Scale
The plugin assumes you connected the data pin to GPIO20, and the clock pin to GPIO21.
Accuracy
Accuracy is limited somewhat by the limitations of the inexpensive load cell, but even more so by the fact that as the extruder pulls on the filament, it exerts forces on the spool, changing the reading.
Nonetheless in my experiments I've found it to be accurate +/- 40g, which is more than good enough.