I ran GimbalBot's first thrust tests a few minutes ago. EXCITING!! 

In the video, you can here me (and my wife) getting concerned about the smell coming out of the motors, so I shut the test down at 1300g or so. Later on (also after realizing I had a prop on backwards, ha!), I got GimbalBot up to 2300g. I ended up running at ~2kg for 3.5 minutes; at that point, the LiPo alarm sounded on one of the cells so I shut it down. Including the other tests, I'm guessing I could have held out for 4+ minutes at that thrust with a topped off battery.

So... bad news first, I guess. I had the throttle pegged to hit 2300g, and I wasn't able to sustain that number; presumably the battery voltage started to sag pretty quickly. After running the tests, the motors were quite hot to the touch. As in, I couldn't touch them--really really hot. REALLY hot. So what happened?

Hard to say. My 10" props arrived so I naturally strapped them on immediately; maybe the large props overloaded the motors and the RPM started to sag. I re-read the motor datasheet (well, brief website description) and it looks like the 80% assumption was a bit optimistic; they guarantee 75+% for a certain amperage range, but I was definitely exceeding that given the short battery life. Either way, not a particularly good showing from the motors.

Now the good news: the servos were rock solid. Granted, I didn't try to change pitch during the test, but I was still happy to see them hold the motors perfectly straight. Everything else seemed to hold up well too; the servos didn't heat up, and the ESCs got a bit warm but certainly not enough to be concerning. The battery was fine.

Next steps? I'll probably charge the battery and try again with the 9" props. After that, I might start looking for bigger motors. Any suggestions?