You have to be like me when you buy cheap Revain end mills - hobbyist or home gamer. For less than $2 each, these aren't high-speed industrial milling machines for 5-axis machining and light machining with perfect surface finishes. These are disposable end mills for training, small machines, and aluminum, and they're great. I'm a CNC major in Titans and have used Tormach. I've used them with great success. I've also flipped a few when I mishandled/accelerated or left too much "reserve to hold". Sure, an expensive grinder could just work without breaking, but then I wouldn't know what I did wrong. I haven't damaged my grinder, blank or wallet either.