Filament roll waterwheel
thingiverse
Don't know what to do with your empty filament rolls? make a waterwheel. paddles adapt to 200mm diameter roll, with 40-70mm inside spacing. you can also add some on the outside. use 2 M4 screws to screw together the halves. and hot glue to the roll. reprint same part 2-8x since Roll inside diameters vary a lot you need to make a axis adapter.
Download Model from thingiverse
With this file you will be able to print Filament roll waterwheel with your 3D printer. Click on the button and save the file on your computer to work, edit or customize your design. You can also find more 3D designs for printers on Filament roll waterwheel.