Thanks for the reply. I haven't ever got the dangling edges before but I did do a small modification on those arms so maybe I left some internal geometry. Thanks for bringing it to my attention. As far as the infill 50% was what gave me the lest amout of flex, as you don't want much or any flex in the arm. Early tests showed some completely uncontrollable crafts with flexable arms as they were counteracting the flight controller. Are you printing in PLA or ABS? PLA being more rigid might be able to get away with 25% but I've never tested PLA arms. I'm ver interested to know what you find. Thanks.