Brio/Thomas Snow Plow (old version)
by ex-nerd, published
Clip-on snow plow attachment designed for Brio/Thomas style wooden trains.
After much trial and error, I would recommend that you try the fixed version, as this version will no longer be updated.
This OpenSCAD library is part of the dotscad project, an open collection of modules and Things for 3d printing.
Print and enjoy.
You may want to break off the tabs if they get in the way. I've also noticed that different trains (even within the same model) have slightly different sizes of plastic covers on their magnets, so you may want to adjust magnet_radius in the scad file and re-render it.