Filament tension sensor

This is a very simple design with a potentiometer, a spring and two bearings to detect the tension of the filament. It is designed for 1.75mm filament, but that is adjustable by the U groove in the bearings. I'm going to use it as a part of a filament winder for my upcoming filament extruder.

I have included all the files so you can edit it as you wish. In the .dwg file I have included is a part to use when your filament is 45mm above the plate, but mainly you probably want it higher, so in the .dwg file and in .stl files there's a design for filament 50+mm above. You can adjust the height with two M3 screws or threaded rods. Sky is the limit.

If you want to make your own bearings like I did, I included the .stl file for printable bearings with U groove. For one, you're going to need 10pcs of 4.5mm steel balls (BB gun ones do just fine) - they are actually 4.3mm in diameter. This ball bearing has 25mm OD and 5mm ID. For more info about these printed bearings and instructions abou