Scienceguyorg Ramblings: Flapping Freebird Almost Flies Away

Friday, October 23, 2015

Flapping Freebird Almost Flies Away

Yesterday was one of those perfect fall days that I just had to take advantage of for some outdoor model aviation fun with a wind forecast of 2 mph and plenty of sunshine. I also wanted to get some video and images for some projects. In the demonstrations I have done I bring along a rubber powered ornithopter; a model that flies by flapping the wings. This is to demonstrate that man first tried to fly by trying to emulate birds. The model I use is the Freebird which can be built from plans found on the Internet.

Freebird Orinithopter

Normally I fly the Freebird indoors but the wind was so light I thought I would try to get video of it flying outdoors. To get a good number of winds in the rubber motor you should use a rubber winder but I just turned the front of the cranking mechanism. The first couple of flights were really short so I cranked in a couple of extra turns in a rubber motor that is really short. I launch again and it is flying around my head, I struggled to get the camera focused on it.

As I continue to watch it through the video camera view finder, I think why is it still flying? The Freebird is getting smaller too so I keep trying to zoom in on it. Finally I realize it is in a thermal air current and it is getting higher and farther away. At this point which just shy of one minute I put down the camera and start running towards it. By now it was beyond a small hill with small trees, from on top of the hill I was able to spot it in tall grass.

I was so happy that I had video of this even with small sections of it not in focus. For something with such a poor glide ratio I would not thought it could fly so well in thermal lift. It did and I had the proof. After this I flew my Allegro Lite RC sailplane and encountered thermal lift that was fair but not real strong. The lift appeared to diminish as the afternoon slipped away so I flew several rubber powered free flight models.