So just had a very quick 15 minute CNC session as time is a bit short at the moment! I've been meaning to see how it is to rout cardboard (CNC router as poor mans laser). After a quick play its OK.. Nice to be able to cut a material in one pass and pretty darn quickly in terms of feed speed. I was worried that it may tear material rather than cut but this wasn't the case and even the smaller ring which is only 3mm wide didn't distort when cut. So it's good.. However it does have the disadvantage of leaving a small burred edge which you don't get with a laser. Also, obviously, your sacrificial material has to be something that can be cut/touched at the same keep and of feed rates or else you may break tools! So I fancy when time allows playing with some 3d print slicing software to see if I can slice a 3d model into layers/contours and then cut from card..