SummaryI'm not a huge fan of the acrylic motor mounts that come with the arducopter kit. I already cracked one of them landing my copter in a tree. This is a one piece replacement that moves the motor inboard by 16mm so that two of the motor screws go through the arm so it's not dangling off the end of the arm. They weigh a tiny bit less than the acrylic ones (8g w/ 75% fill vs 10g) I haven't flown these yet. I'm still printing them out. It should be pretty easy to modify this for different motors (I already have some constants in there for some turnigy motors I have but I haven't tested them out yet).InstructionsPrint them out. Slide them onto the end of the arms until the outer hole lines up with the existing hole, I warmed mine up a bit with a heat gun to make them go on easier (they are a tight fit). Drill another hole through the other hole in the motor mount. You may want to drill it from one side and then the other rather than all the way through so you don't miss the hole on the other side. Secure the motor with 2 long screws and 2 short screws.