Double-sided ski scrapper sharpener. One side is 3mm (ski scrapper), the other one is 6mm (big snowboard scrapper).

There is a slot to insert a file, mine is Toko Base File Radial 100mm.

You can use another one, but you'll have to change the dimensions.

I've added a hole on the side to push the file out.

The Onshape document is available, with several variables to change file or scrapper dimensions.