eric's model flying blog

I I wanted to prove to myself that I could program an Arduino Development board to function as a flight controller. Pretty much the same algorithm can be used to control a camera gimbal to keep an action cam steady on a wobbling quadcopter. But since I got the quadcopter to fly already, I did not feel the need to prove myself all over again. So I just bought myself a  HAKRC 3-axis Gimbal  to put my cheap action cam upon. I have a more expensive Drift HD Ghost, but that one weighs about 200 grams, while my cheap no-name GoPro clone only weighs 56 grams... S the choice is simple. It will not render super quality images, with 1080p at a very high compression rate, but it will give a nice idea of the possibilities. But, just simply spending money on a gimbal doesn't get you there. There's a whole brunch of parameters you can play with to get the response you want from each of the three axes. It is hugely important to make sure your action cam sits on the gimbal in perfect b...

OK. What!?! Vortex Ring State! It's the helicopter variant of a stalled wing. I had not heard of it yet, when I fist encountered the effect. It comes down to this: if you descend vertically, and you do that relatively fast, you get into the downwash of you own propellers. That will cause your props to loose lift, and you descend even faster. Your natural reaction would be to throttle up, because you are now descending more rapidly than you planned, but that makes the downwash - and therewith your predicament - only worse! The only thing you can do is pitch or roll to move out of that vertical column of air, not necessarily with more throttle. Only: you have to think of that, and act on that, before you hit the ground... I didn't. It caused my quad to "land" on one arm, and that was a touch too much... So now I had to go shopping for a new frame arm. I decided that buying a new frame would be a better option, because it is not that much more expensive, and I could imme...