The new propellers was a success

Last night I tried out the new 8 inch propellers along with a fresh motor to replace the last faulty one. The x550 now spins like a cat and flies like a bird. I trimmed the flight controller for the new propellers, which wasn't all that much to change and it's very stable.

After the basic trimming I started working on navigation and RTL (return to launch). These also has a set of P, I and D parameters for navigation. There is a good guide over at the ArduCopter wiki. However, I didn't have much success in trimming the RTL and the x550 always overshot or navigated wrong. Once both batteries were drained, I figured out that I'd trimmed using wrong parameters, dooh! I had been trimming the HLD_LAT/LON instead of LOITER_LAT/LON. Will have to do this at some other point where I can find a good field to try it out at.

Link to the guide: https://code.google.com/p/arducopter/wiki/AC2_loiter_PID

One motor down..

Yesterday, I started trimming the AltHold function that relies on any altitude sensors. The sensor I have so far been using is the barometer, which is very noisy. That means it's less then perfect at holding it's altitude, but works +/- 1-2 meters.

Today, I thought of doing some more testing, maybe even try the AutoLand function as the AltHold seemed to work. However, after a few minutes of flying this happened..

 

One of the motors came off upon takeoff and took a piece of the radio antenna with it. The motors are fastened with two screws at the bottom and it seems as it came unscrewed, possibly due to vibrations. This seem to be the case for one other of the motors when I checked them all. It seems as checking the screws before going flying is a bullet on the pre-flight checklist.

Now, I only found one of the screws, which means, I have to get another somehow. Not sure if I should order a whole new frame as spare part or if I should try to find one in a local utility store. I'm going to try the second option tomorrow to see if they have any thing available that would work as a substitute.

Yes, there will be more videos. I have two that I filmed yesterday when doing some trimming but I haven't uploaded them to YouTube yet as my bandwidth is limited and the amount is not unlimited at the moment.