A mechanical filament tracker that shows the usage of your filament. Fully mechanical, works with standard 1.75mm filaments, almost all the parts are printed, the minimal non-printed component requirements are 2 types of 3 ball bearing in total, even screws are optional.

Can be easily put on your filament box, vertical or horizonal, or anywhere you wish. Just thread filament in, toggle the hands to the initial position, and then you will be able to see how much filament is used or left.