This gear is part of an Electric Skateboard build, the 3D concept files are on instructables: instructables.com/id/Electric-Skateboard-With-In-wheel-Motors/
The Scad file number 2 (skate_gear2.scad) has holes and it's pretty easy to configure, just download openscad, download the scad files from this project, open and tweak the skate_gear2 SCAD file with your configurations if needed, render, export STL and print!
A fill value of 60+% should do!
TODO / Next Steps
todo: add nut holes
todo: design back-plate
todo: Add wheel pressure convex part for a better fixing to the wheel
Openscad, fork/remix of the awesome Parametric Pulley scad project, profile 14 (gt2 5mm), teeth 40, motor shaft 30 (even if it could be smaller)