I've sharpened the two blades from my Dewalt 12" machine once. I think I did good. The other set is in the machine now (Pre Tormek - need two - one in use one to be sharpen - or sharp on stand-by). I Believe I was being a little heavy handed (I'm 6'2" at over 260# - lots of beef). As I leaned on the blade it caught the wheel and the whole thing recoiled and put a fair slice in two fingers (healed ok). So one piece of advice - go easy. I've only had my machine for a littel while and with the holiday rush I have done little shop upkeep. but one of these days I will do more. LOVE it thus far.