Filament clip [definition] : Typically a device attached temporarily to a filament reel  to hold the loose end of filament so as to keep the filament from unwinding.

I have tried numerous different styles of filament clips (and designed a number of them myself), and I have never been 100% satisfied with any of them. A few I have tried are acceptable (but still with minor deficiencies), so every once in a while I feel the urge to try again to design the LFCYWEN (Last Filament Clip You Will Ever Need). One of the difficulties of designing the LFCYWEN is that there is no such thing as a standard filament reel design - they come in different thicknesses, with and without a rim, with different rim widths and thicknesses. As a result, a clip which works well on one vendor's filament reel may totally fail on a reel from a different vendor. 

Over the years, I have collected empty filament reels from a number of different vendors. To facilitate testing filament clip designs, I measured the profiles of a representative (I hope) sample of reels, and created model which combines all of those profiles into a single print which can be used to test new filament clip designs. The model is based on filament reels from these vendors (from left to right on the model) :

• Hatchbox

• 3D Filaments

• SunLu

• MonoPrice

• Prusa

• ROHS

The profiles are intended to represent a cross section the outer diameter of a reel. For simplicity and ease of use of the model, I have not modeled the curvature of the reel diameter, but for the small "section" taken (10mm) the amount of curvature is not significant.

Caveat : Reel styles may not be standardized even for a single vendor, and may also change over time, and of course there are almost certainly vendor reel profiles not included here. However, I think the model includes enough variation that a clip that works well on all the profiles in the model will likely work well on whatever styles are "in the wild."

The "scale tag" you see in the photos can be found here :

https://www.printables.com/model/1710483-scale-bartag

Assembly and Use

 No assembly required, of course. To use the model, just try using your filament clip on each of the six test sections; this will tell you whether your filament clip design will fit the rim of various styles of reel.

Print Instructions

Print in PETG using the 3mf files provided, otherwise :

• 0.2mm layer height

• 2 perimeters

• 15% grid infill

I used PETG just because I already had it loaded in the printer, but PLA and other filaments should work just as well.

CAD

The OnShape 3D CAD files for this are here :

https://cad.onshape.com/documents/d3a2dafd2126a44627bdc873/w/03f80bcf443cc640f2ad2238/e/8f3d7972742eed169ac2ec9b?renderMode=0&uiState=6a0a0d509af3cde7687bfd67