This is a fairly complex automatic tree farm that I made a little bit more complex than the system that direwolf20 made with his Rube Goldman machine. This uses Technic Pack 7.2.0 which can be got by selecting the options menu when you open the Technic Launcher then select "always use development build" then just login and it will change the files needed to be updated so make sure that you back up any existing worlds. There is a YouTube video of this creation on my channel. Here is the link:

http://www.youtube.com/watch?v=qzREvoeeiR4&feature=plcp

Hope you enjoy the video and hope it helps to explain the build.