petthekittyz
Heliman
Location: redding ca
| tons of props???the number of blades doesnt matter, the lenght doesnt matter, as mush.. the only resistance is going to be the actual downforce being created by spinning the top blades, what your going to want to do is have a very efficent way to drive the top blades. im going to say the heavier the blades the better, you might think im nuts but let me explain my reasons.
you start powering the blades with them flat, no down force at all. get the speed up as much as you can, the more weight the more momentum, the more stored energy.... think of it like a fly wheel, kinda... if you have time to get it going before they push you down the ramp things would be great. once they are as fast as you can get them just leave them free spinning, change over to start powering a smaller rear prop, probably 3 small blades. your dropping down the ramp, right before you hit the bottom you pull some sort of release, havent figured out the mechanis yet, that releases the top blades from there flat spin to an aggressive amount of downforce, maybe spring loaded with release pins? sure why not? that would give the contraption tons of lift, once its lifting, keep the top prop pretty flat, or even lean it forward a little to add to the forward movement of the contraption, well with that small amount of power being generated by the person at that time you could probably just leave human power to the top blades without TOO mush fear of the whole machine spinning like a helicopter without a tail prop, lol. if these problems arise upon testing just dont use power on the top when it is in the air, it can spin as fast as it wants without causing any difficutys durring flight as long as there is no power being applied durring flight. the only thing im worried about is the drive mechanism, when were only talking about maybe 1hp from a human, we need a very smooth means of transfering the power with minimal power loss.... hydraulic pump and motor? or flexshaft??? i dont really like flex shafts.... this thing could go pretty far, maybe. and the cool thing is as long as the top blades are spinning they act as a giant wing as well. maybe have the top blades set in a 3 position thing, 1st setting flat for speeding it up, 2nd setting: aggressing downforce for lift, 3rd setting would be backwards, almost as if it was pushing the contraption down, but only go to that setting once the lift is gone. the blade change over so the falling motion on the machine actually starts to power the blades and you lean the whole upper blade assimbily back to maybe 20 degrees, which would inreturn give more lift if you were powering the rear props. |
I should see if i can find a report on human powered helis, it had a complete math breakdown. That was 5 years ago though, and reports on unsuccessful projects tend to go away quickly...
(lo_tek).
.
. Ya think he could have thrown me a bone for a couple hundred grand
