Sup fin retainer plate

Yesterday I lost my retainer nut for my SUP fin just before training (it fell through the planks on the pier, good luck finding it back). Luckily someone had a spare one, but I immediately was thinking about creating a 3D printed extra. It should be plenty strong for most applications, but use your brain (if you are SUPping jaws, please don't use it and blame me ;) )

I created two models, both for M4 as that is what my fin uses (but I can add more sizes if you want). One model is using a press fit M4 nut as a thread and the other is just a precise fit on the bolt which you can tap into the plastic.

The one using the bolt feels stronger, but I cannot separate the other one with my bare hands, thus I think it should suffice (and it is way easier and cheaper to make).

If you need a special size you can find the OpenSCAD file here: https://gum.co/DiIab