Spindle mount for the ShapeOko CNC mill, using a Proxxon IB/E (20mm collar).
3D printed spindle mount. Run a properly sized drill bit through the holes to give a little wiggle room. Light filing or sanding of the mount may be required to ensure a snug fit in the aluminum piece that bolts onto the MakerSlide.
Use your best judgement on infill; 40% seems pretty solid to me.
File created using Gimp, Inkscape, TinkerCad.