I created the gears for a busy board I’m creating for my grandchild. The busy board will contain may hardware items and is not intended to be used unattended.
WARNING: It is possible to pinch fingers between the gears.
I used Inkscape’s gear extension to create an outline of the gears. I saved the file as a .dxf file. I used the .dxf file in OpenSCAD to extrude the gears. I then removed the finger hole and center screw hole with OpenSCAD. I saved the object as a .stl file. The process is a little more complicated and I may expand on it later.