Hallstudio has been flying RC planes since 1989, lots of things have changed since then. Check out this great Cheap Tricopter Build that he put together. It comprises of a bunch of inexpensive parts that total around $100 but give you the a great tricopter base that you can fly and modify. There are lots of interesting tricks that he demonstrates in the video such as the use of a drywall screw as a simply pivot point which allows a cheap $5 servo to move the tail rotor. If you want to build it he has provided a full list of all the parts needed in the comments of this video. Once you have the tricopter built you don’t want to be knocking into yourself or other things while you fly the thing. Check out the video below where Hallstudio demonstrates a simply but effective carbon fiber beach ball like cage that allows you to bump into things from all angles with no issues. I guess things like the AR Drone has similar crash resistant properties but there is something very cool seeing the flying sphere.