Shimano Cassette Spacer

I designed this spacer to fit a Shimano cassette bicycle rear wheel, because my gears cassette was shorter than the hub.
The inner part has the shimano tooth pattern, and the disk extends a bit outwards of the external gear so as to avoid the chain entangling itself in the spokes if it derails too far inwards.
This is my first try at using FreeSCAD for part design and it's pretty cool, I'm using the built-in spreadsheet feature to make a parametric design, where you can easily modify the overa