I wanted a simple hard sided case for my Hiby R4 but none seemed to be available so I made one myself. I printed in PETG Glass Fibre (Eryone) because it looks good, has a texture that is easy to grip and is pretty darned tough. It should print OK in pretty much anything you care to use though. I went with 0.2 layer height and 3 walls with infill at 20% rectilinear (though there's not really much to infill). I do recommend using supports to keep the holes neat and tidy. In the latest version I've made a couple of small refinements to the cut-outs. It fits perfectly and I'm really happy with it.