So something like this?
Or maybe have the nose prop below the body and the tail prop more above the tail so there is a more of a quad-copter look for stability on takeoff.
This design I like, but I would want the horizontal bars holding the motors to rotate forward for airplane flight. And if the rear rotors are slightly under utilized because of being in the wash from the front, what does it matter? In forward flight they are only required to produce enough thrust to overcome the drag. This is less that is needed to hover.
I am guessing that the 'plane' in this photo is simply a mockup, with no functional controls other then the fixed rotors of the quad.
http://forum.arduino.cc/index.php?action=dlattach;topic=466058.0;attach=207134
That's more motors & weight then. Technically it should be feasible. I don't know the effect of propwash from the front props on the back props, which you brought up earlier. I suppose you could put one together that way before diving into rotating the motor shafts and see how it works. The effect will likely be different for different sized planes too.
CrossRoads:
I don't know the effect of propwash from the front props on the back props, which you brought up earlier. I suppose you could put one together that way before diving into rotating the motor shafts and see how it works. The effect will likely be different for different sized planes too.
I could fix the decrease in prop efficiency by simply having the forward props turn at a slightly less rpm than the rear props to make up for the decrease in air density the propwash causes between the props. But I'd need to figure out the physics that surround the problem to find an appropriate equation. On the other hand I could off set the front and rear props on the horizontal axis to avoid the propwash, but that could screw up the quad-copter functions.
As for the weight, ill be using balsa wood covered with a spray on plastic for the housing unit. Or do you think I should spend the extra cash and get some type of high density foam for the housing?