Since my Skywalker is a 3.5kg beast and has a camera window for aerial surveys, I had trouble launching it without my catapult. This was mainly due to not having a good grip on it, so I designed this gripper that falls away right after launch or can be just held on to since it relies on the planes weight to stay attached. The two parts fit together with no play, so you might need to sand a bit to make them click together. Here is a video of me using the gripper: http://www.youtube.com/watch?v=drXDnwVMlHQ&list=UU5z9cL0hwDJsXeZ-OZufVqgPrinted with low infill 10% will do.