Filamentclip with locking mechanism to stay on the spool even when printing

I have tested some but not all filament clips and was not really satisfied with any of them, each could do one but not the other. I wanted a clip that would stay firmly on the filament spool and not be an obstacle when unwinding the filament. But it should also be removable.

Countless attempts later, this is the result. For me it works wonderfully and I have learned a lot.

Maybe this model is also interesting for one or the other. But be warned! You will probably have to adjust your settings in slicer and the printer should be well set. For example, I had to reduce the flow to 0.95 on my printer so that the clamp didn't get too tight. ( In the CAD programm, however, the distances looked perfect ).

If the slider does not close properly, carefully enlarge the opening where it clicks into part1 with a drill or file.

I have many empty filament spools and could test on which ones the clip holds. With most of them it worked, only with 2 spools it didn't.

I printed each part individually with PETG, as I don't think PLA will do. Layerhight 0.16. 

For Part3 it is absolutely necessary to align it on the print bed as shown in the last picture, otherwise it will break when mounted on the spool ( look on picture nr. 6). Because you need a bit of force to push it onto the spool. You then inevitably need support. 
Also part3 has to be glued to the back of part1 with super glue ( picture nr. 4+5).
Unfortunately, I have not yet found a way to join the two parts into one piece and print it without problems.

For part2+part3 a brim is recommended.

I have attached the step files so that anyone who wants to can change them. I‘ve also added part1-b for the other side of the spool.

Here you can see how easy it is to thread. The slider even creates a threading aid.

Retightening is no problem due to the automatically opening shutter.

The clip is not an obstacle for the filament during unrolling

Easy to fit.

So we are ready to go. (Completely unnecessary GIF because it says nothing…)