Model Building 101> Ornithopter Hovercraft

[KJELL]

Hi Willi.
I like this wing arrangement. If you can get a good flapping frequency it wills takeoff without problem. .
Kjell

[wmueller10]

Kjell,
Pic 1, Yes it may very well open the door to another breed of ornithopter.

{edited}
Forum members,

Pics 2-3, Inverted shot of the hovercraft. Without main wing support, the upper fuselage bends like a weed in the wind (fuselage material G-10).

Pic 4, A second ornithopter hovercraft is in this photo, can you spot it?

Pic 5, Wires hanging everywhere! Servo sequence control is complete. All that's left is to install the battery and wings, strap the loose wires in place.

[KJELL]

Hi Willi.
I think it is a question of flying by thrust or flying by lift.. .
Kjell

[wmueller10]

Kjell,
I will use the same wing arrangement as in Post #1,,,(answer to post 15)

Pic 1, All servo wires secured to fuselage and a battery extension wire added

Pic 2, Battery pack installed at the lowest point possible

Pic 3, Final picture of a wing less craft'

[KJELL]

Willi,
I am impatient to see the wing combination.
Kjell

[Chronister]

Hi Willi,

Thanks for posting the video of your new hovering ornithopter. I'll add this photo of my own ornithopter which appeared in the Winter 08 newsletter. We are using a similar setup (based on Delfly vertical takeoff model) but it looks like you've got bigger control surfaces on yours, which will be helpful. Mine flies nice, but it won't do rolls and stuff like I was hoping.

I see in the photos that you are using two separate motors. Are they synchronized by meshing gears?

Nathan Chronister
The Ornithopter Zone

[wmueller10]

Nathan,
Are you talking about this Defly hovering ornithopter?

Observing the picture below reveals a standard tail empennage, you have a rudder and elevator to which only the elevator is directly in the crafts’ wing sweep. It would suggest to me this model lacks 100% control in a hovering mode. I suspect the ornithopter needs to quickly get off the ground (assuming it can take off vertically) and gain enough airspeed so the rudder can be used,,, but has no chance of a vertical landing.

If the paddles on my aircraft are set right, I should have total control in hovering flight. The model’s sole purpose will be to ‘only’ take-off and land vertically. Absolutely no aerobatics Or classic flying with this one.

With this flying experiment, the hurdle has been scaled back and set low. If I can take off vertical to a height of 10 foot, maintain controlled flight for 15 seconds and land without crashing the experiment will be a success.

>>Are they synchronized by meshing gears?>> Yes, the design serves two purposes, 1 locking in counter phase wing movement, 2 allows for mechanism conversion, over to a single motor drive if needed.

[Chronister]

Hi Willi,

On mine, I set it up so the "elevators" could be controlled independently, working as elevons to provide roll control.

The Delfly photo you posted looks like the Delfly I was talking about. It has only rudder and elevator control, however it is able to take off and land vertically despite the possible lack of airflow around the rudder. I actually saw it land upright on the tail when they flew it at the NEAT Fair. It might be the case that some forward speed is required for steering, and that it only has elevator control when making a tail-first landing. Bart Remes said it does require some control inputs when hovering, but it seems remarkably stable.

[wmueller10]

Originally Posted by wmueller10

Defly hovering ornithopter,,, has no chance of a vertical landing.

Nathan,
It's quite obvious I'm behind the times, what else can you tell me about the Delfly aircraft?


Added March 6th, 2010;
Two years later and after seeing the Delfly video. I can say that I sure got it wrong, it can take off and land at will.

On my Vtol, not enough wing thrust was produced to get the 879 gram aircraft airborne.
In a attempt to salvage a portion of this project. A helium balloon was attached to get it off the ground and demonstrate it's control abilities. So far the experiment reveals that wind, helium balloons and flapping winged aircraft don't mix well.

Here's a video of test 1.
http://www.youtube.com/watch?v=ZICmrHDlT3A

[Velko Velkov]

Willi,

You can try with "ADAPTIVE ORNITHOPTER WING"