This is kinda cool. It's got that tilting back prop, but on that boom its got another forward thrust motor.
@Jonas - That was great! Good find. That thing fly's like a fixed wing! I couldn't believe it when he punched the throttle. Cool. I found a video on how he did it. That fourth propeller rotates around the back boom. Very clever. Here he uses the same mechanics on a fixed wing. Also clever!
Found this post from the gut on FPV Labs. Looks like he made it on a 3D printer: Source: http://fpvlab.com/forums/showthread.php?15960-New-motor-mount-concept.-The-Boom-prop!
Don't know what the real value of this is, but it''s sure cool. It would be fun to build one "just because". ...Tiger
I also don't know why you'd want this on a multi rotor even though it is pretty cool. What I thought was interesting is it's use on a glider in one of the above videos I posted. Having the propeller on a boom like that seems efficient and a good way to quickly setup CG for different batteries since it is just clamped to the boom. That you can run servo wires through the boom, and the motor spinner, seems like a pretty clean and handy thing. What was also interesting was the comment about using two on the same boom (fixed wing/glider) in a couple possible configurations. One with two systems on the same boom (coaxial) with opposite turning directions to counteract torque twist and the second also using two systems on the same boom but one with a large shallow pitch propeller for climbing and the second with a smaller steeper pitch for cruising.
