I had something interesting happen to me last week, which I would like to share. I scratch-built a Quad V-Tail with a Pixhawk on it, but kept having strange flight issues I could not figure out. After talking with some folks, I decided to scrap the V-Tail design and build a standard Flamewheel 450 Quad which is about as common as they come. Since I wanted to have longer flight times than is standard with one battery, I installed (2) two Floureon Lipo's rated at 11.1 v and 3000mAh. I could only get 15 seconds to 30 secionds of flight time out of it before it went into alarm and laned. In Mission Planner, I had the battery settings at 11.1v and 6000mAh too, but can only assume the Pixhawk volt,amp monitor didn't like the load each motor had, trying to lift the heavy load. (extrra batteries).
I admit, the Quad was pretty heavy, so I decided to change to a single battery rated at 11.1v and 2200mAh. The darn thing flew for 8 minutes 15 seconds to my surprise.
The reason I am using the Pixhawk flight controller is the fact I eventually want to build a large X8 for aerial photography but want to learn all I can using something less expensive.
My questions are,
1. How does the Pixhawk determine if the motor loads are correct?
2. Is there a website which explains proper motor, prop selections based on copter function?
There might be a time where I want to lift a heavy camera for a quick photo shoot which might only last 3 minutes, but if the Pixhawk doesn't understand this, what do I do?
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