Grommet for a filament box. The aim was to build a feed through hole for a filament box with a tight opening for a 1.75 mm filament. Also, the grommet should be designed in a way that unused filaments are accessible from outside without opening the box.
My first experience after 2 weeks of usage is that the clamp which should hold the filament works well when the grommet is closed, but be careful when opening the grommet and pulling the filament by the clamp, the filament might slip out.
Also my first approach do design a thread in openscad.
08.04.18 Update: I changed a bit the "spring" design in the clamp to increase the clamping force. However, filament usually has a smooth = slippery surface. But I think it's holding the filament better now. Since the overall design did not change, those who printed the grommet may print and replace the clamp only.
Design parameter for filament size, thread and handle properties and heights, tolerances, ...