I wanted a precise way to balance the copter while suspended so I could get the most accurate balance reading. I've seen guys use bungy cords and anchor them from the battery tray but I didn't think it would be the most consistent way to go about it. So I took the stock battery tray measurements and created an aluminum plate that would bolt on top of the existing battery tray. MSC had the biggest selection of standoffs that I could find but even they didn't have anything longer than 24m bolts so I decided to just take 2 of them and stack them to give me enough room for the batteries. For those interested I used M3X25MX4.5m standoffs MSC part #77124410 I'm using 80 pound fishing wire and a fishing sinker with a loop under the plate for the mounting point. The hole in the aluminum plate is exactly in the center of the copter. I used the center of the battery tray for reference. As you can see my copter isn't very weight balanced because I have my FPV transmitter, Voltage regulator for the orientation lights, and Xbee all toward booms 2 and 3. I will temporary balance the copter by putting the lipo on booms 7 or 8. The FPV camera isn't mounted on here yet as well which will affect the balance point slightly. I'm going to try to balance it without the camera gimbal in case I want to flight it without it. I will then balance the gimbal and then with the gimbal bolted on the copter it should be very balanced.