I don’t think I’ve shared this yet, it’s a coin I made for a geometry nerd awhile ago. Just playing around with sine waves and trying to visualize in 3D.
The really neat thing is that this is only 0.5mm to 1mm deep if I remember correctly. That means it’s super quick to knock out and relatively low fuss in terms of tool path generation.
This was polished after cutting (which is apparent by my hands) but it doesn’t take long and you can trade more machine time for smaller cusps/less hand work if necessary.
One of these days I’ll get a 1/16 diamond ball endmill and take cuts lighter than air to all but eliminate hand polishing…haven’t earned that luxury quite yet 
Anyway, playing with light can be pretty satisfying. Give it a try sometime 
Backside is just a simple stepped target but it still looks neat.
