Howdy,
Multirotors with IC engines have always been an issue, because it's not easy to sync/stabilize the engines with eachother.
Well, there's a german company, that seems to have solved this:
[youtube]http://www.youtube.com/v/KIIIwNMz7ow[/youtube]
Here's the video from the evolution of their quadcopter:
[youtube]https://www.youtube.com/v/wCGIctmymts[/youtube]
What they've done is taken 4 nitro engines, that can be converted to 2-stroke. They also have fitted 4 BLDC engines. So one BLDC and one 2-stroke 10cc engine per rotor.
The BLDC engines are used to start the IC engine. They also help controlling and adding accuracy to the rotor, they serve as alternators for the LiPO that powers the onboard electrics and they act as emergency engine, should the IC engine fail.
The project was set up as Kickstarter project and has been funded.
https://www.kickstarter.com/projects/1600545869/yeair-the-quadcopter-of-the-future-from-1399/descriptionSpecification is that it weighs 4.9 kg, is capable of a 5 kg payload, top speed of 100 km/h, range 55 km (2 km from remote) and flight time between fueling of 60 minutes.
To prove it's capabilities, they decided to let it lift a beer keg
That video can be found in the campaign under updates.
Thought it might interest some people here. I actually have backed the project, so looking forward to getting my IC quad next year, if all goes well.
/N
