Stuff You Need | Tail | Wings | Fuselage | Flapping Mechanism | Install Wings and Tail | Flight
Before flying, bend the tail slightly upward. Start off with some low-power tests to get the model adjusted right. This should be done indoors or in windless conditions. Wind the motor 40 times. Launch the model with a gentle forward push (do not throw it) and observe the flight path. Try winding the crank both directions to see which works best.
In the low-power test, this ornithopter should slowly descend while flapping its wings. If it makes a nose dive, bend the tail up slightly. If it stalls (tries to go up, but then drops sharply), bend the tail down a bit.
Twisting the outer portion of the crank with pliers controls the flight direction, left or right. Adjusting the crank changes the flapping angle, and therefore thrust, of the right wing. For best results, try to make the model fly as straight as possible.
Once the model is flying fairly well, you can wind it all the way up to 130 turns. That should give it more than enough power for climbing flight. Further adjustments may be required after you see how the model behaves with more power.
Ornithopters are fascinating to watch, but experimenting with them is even more captivating. Here are a few ideas you'll want to try:
- Put both conrods on the rear portion of the crank. What happens, and how is the flight affected by winding the crank in the opposite direction?
- Make a new crank with larger or smaller dimensions. What happens?
- What happens if you apply the wing covering tighter or looser?
- Try different wing sizes, shapes, structures.
- How can you make Freebird 2 stay up longer? You might try lightening the tail, using tapered wing spars, or lengthening the motor stick. If you lengthen the motor stick, how can you maintain stability with the more rearward balance point?
- Try to build a biplane Freebird resembling a dragonfly.