Model Building 101> Ornithopter Hovercraft

[wmueller10]

My original hopes were to build a hovering flapping winged aircraft that used wing warp for maneuvering control, it would of been a first.

Unfortunately, my method/type of wing warp needs airspeed to work as intended and a hovercraft flies with very little or none at all (a slight fact I had set aside). The result was a model that did indeed fly but no effective way to control it. Another problem was no inherit stability. Various ways to correct this problem also failed, fuselage weight shifting and moving the CG back were not enough to stabilize the out of control model. When one of the motors burned out, I put the hovering project on hold to pursue other flapping winged interests.

Now with my new work shop finished, I'll attempt to get the hovercraft airborne one more time. Their will be no firsts' here, I'll use aerodynamic control surfaces just like the "Mentor" used years ago. I guess it would be appropriate to call this one "Mentor II" (if it can fly by flapping wings alone).
Willi

[KJELL]

Originally Posted by wmueller10

My original hopes were to build a hovering flapping winged aircraft that used wing warp for maneuvering control, it would of been a first.
Now with my new work shop finished, I'll attempt to get the hovercraft airborne one more time. Their will be no firsts' here, I'll use aerodynamic control surfaces just like the "Mentor" used years ago. I guess it would be appropriate to call this one "Mentor II" (if it can fly by flapping wings alone).
Willi

Willi
My congratulation to you for your new workshop. You have demonstrated your high lever in building flying models. I and many members are waiting to se your next demonstration.
Kjell

[KJELL]

I made some test with my KD-Fan to make a hovering model but the motor was to slow to obtain the power to hover. I left it on the shelf for a later moment.
Kjell

[wmueller10]

That's a very nice looking model Kjell.

Pic 1, Here's my last resort to getting the hovercraft airborne. If all else fails, I'll add a few balloons to get it aflyin'. Of course by then the project will have failed, but I'll use the opportunity to figure out paddle sequence for X and Y axis control (what?).

Pic 2-3, Another possible control solution in a zero airspeed environment, is Dr. Korobelniks "wing differential". Wing set 1-2 counter acts wing set 3-4 providing true asymmetric control (preventing fuselage roll).

Pic 4-5, A few more assembly photo's, fin angle matches mean wing position.

[wmueller10]

Pic 1, "Mentor", worlds first remote controlled ornithopter designed to hover

Pic 2, Outline of my model is now complete, weighing in at 749 grams, with wing sails, battons and battery (not installed). This does not include the servos, RX or depron fin material. Target weight is 850 grams anything more, the aircraft is less likely to fly.

[wmueller10]

Here are a few pictures showing assembly and construction methods,,,, 1/8" carbon rod and depron controlled surfaces weights in @ 3.5 grams each (x 4),,, a servo tray, 4 servos, linkages will be an additional 40 grams,,,

[KJELL]

Hi Willi.
It will be interesting to se the Wing arrangement.
Kjell

[wmueller10]

Kjell,
Expectations of 'controlled' flight are low but I must finish this project before moving on to the next.

[KJELL]

Willi.
I am talking about the wing arrangement of the Hovering project.

This is the result from the wing test.

W1 = original PH wing without modification.
W1 Flying Speed 5.5 met/sec. 1.46 met/flap
W2= The triangular flat part eliminated.
W 2 Flying Speed 6.7 met/sec. 1.76 met/flap 21% faster than W1.

Kjell

[wmueller10]

I can see how the W2 wing has less resistance but it also has less wing area channeling (directing) airflow over the thrust portion. I think W1 is a better choice for flying in zero airspeed and should have better traction.

W2 is a good design however, most certainly it can be used on this type aircraft.

Below is sketch of your wing. In this configuration, the flap mechanics are closer to axis point (not as top heavy), will increase inherent stability.

Pics 2-4>> Servo tray installed, final weight 48 Grams w/servos

Pic 5, Linkages installed, materials used were music wire, sewing thread, tooth-picks and CA glue, weight per linkage 6 tenths of a gram (x 4)