Short flight ending with a crash. I notice a beep tone coming from the copter just before the motors cut off, In the GCS, a message appeared (DCM BAd Heading)

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Comment by Richard Kennedy on March 17, 2015 at 3:03pm

Did you ever get this figured out? I recently set up a quad and after setting in all up I kept getting the DCM Bad Health warning. I finally figured out to do the motor comp but only go 1/2 throttle. Not sure why but that fixed the error for me.

Comment by Richard Evans on March 30, 2015 at 6:41pm

I believe that my problem was that the takeoff point (2 different ones) were on the roof tops on multistory structures that contained a lot of iron beams supporting the roof. I believe it was magnetic interference. As soon as I took off, the effect of the magnetic field changed rapidly as compared to the calculated heading therefore triggering the DCM.

Richard

Comment by Richard Evans on March 30, 2015 at 7:19pm

Hi  Some advice is would be very helpful, I'm not sure where to start.  

I flew my QAV 550 quad with a Pixhawk  flashed to 3.2 yesterday in winds around 15 to 20 mph.  I just wanted to test it.

The wind almost had me backing out, but I decided it would be useful to see if it could handle the wind and that it had enough tilt to make headway agains the wind.  I took off, and went up about 10 feet in stabilize  and I had to hold it tilted into the wind pretty good, but had no problem holding position in stabilize,, but it was  hard work fighting the gusty wind  so I decided to try it in position hold.  I landed first,  set it to position hold, I had 12 sats, and HDOP of 1.6

It lifted off and went up fine, held position very well, but due to the gusting wind, altitude was not locked in as well.. The throttle felt very sticky.. it was like the deadband was large, but when I wanted to go up or down, i had to give it a lot of stick change, but once I reached the point that the copter would react, it seem to be fairly sudden and pronounced. The wind was gusting and even with the stick in the deadband, a gust would start it climbing aggressively  and I had to drop the stick quit a bit before it would break the climb, then it would want to go down quickly and I had to give it a bit of throttle to stop it.  It wasn't that hard to get it back in the zone, but it seem like I needed more authority around the center but less at each end..

It seemed like if I wanted to come back down after at unexpected climb, I would have to drop the throttle low to get it moving down, then I could't stop the descent by just moving the throttle bad to the center, I had to raise it above the deadband to get it to stop and hold altitude.

This could be just the effect that wind is having on it, I've yet to fly it in calmer air yet. In less wind, it wasn't noticeably difficult.

Are there parameters to adjust this, and if so, how do I go about tuning it?

Richard

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