Hi all,

First post on LibrePilot, first multirotor with LibrePilot, and I'm having difficulty getting my ZMR250 frame / CC3D flight controller to stabilize in attitude mode.

Upon taking off and waiting a few seconds, the horizon on the GCS PFD will slowly pitch downward. The quad will attempt to compensate, resulting in a dramatic change in pitch over the course of a few seconds. In my hand, the quad will continue to pitch backward until its pitch is about +80 to +90 degrees, then it will begin to slowly level off.

I can usually trigger this quickly by increasing to max throttle, but it sometimes happens on the lowest throttle settings as well.

The symptoms don't appear if using Rate stabilization, only Attitude.

Other forum posts have suggested raising the accelerator filter, but the symptoms occur at 0.20 and 0.10.

Also, I have been flying the same quad for months using the stock OpenPilot GCS / Firmware, without issue in attitude mode.

Any help would be appreciated. I'm familiar enough with the interface for the basics, but I'm still trying to learn about some of the more advanced tuning that can be done through LibrePilot.

Thanks!

f5soh

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Re: ZMR250 - PFD / Horizon constant pitch downward in attitude mode
« Reply #1 on: May 13, 2016, 09:10:59 pm »
You must need to reduce vibrations or change your board mount.

Try a static test with motors and monitor the PFD behavior.

jbarchuk

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Re: ZMR250 - PFD / Horizon constant pitch downward in attitude mode
« Reply #2 on: May 14, 2016, 01:06:04 am »
These two lines...

... first multirotor with LibrePilot, and I'm having difficulty getting my ZMR250 frame / CC3D flight controller to stabilize in attitude mode.

and...

Quote
Also, I have been flying the same quad for months using the stock OpenPilot GCS / Firmware, without issue in attitude mode.

... imply that you did 'something' different in the setups between OP and LP. Figure out what that was and you're golden. Maybe a calibration thing.