APM 2.6 - Yaw input causing flip and crash

Log Analysis -- deprecated Copter Logs -- deprecated
1

Hi there,

Long time reader and first time builder. I’ve chosen a Tarot 680. 800v motors with 11x5 props. 4S 4500mah. APM 2.6 is the brain with 3DR Ublox. Taranis transmitter.

All the hardware is set up correctly, motors tested and responding as normal. I’ve flight tested it three times. Havant Autotuned yet, but it hovers fine. Pitch and roll respond well.

But even a little Yaw input causes it to immediately flip and crash. I’ve pulled up the data flash logs and it looks like Yaw is corresponding with desired yaw as expected. But the Yaw input is causing a extreme roll & pitch? :frowning:

Thankfully, I tested in long grass at low altitude, which reduced the impacts. But I’m struggling to figure out the cause and hesitant to put it in autotune until I do (since a failed autotune will mean a drop from 20m).

KMZ file and screenshots of the log graphs are attached. I am in uncharted (for me) territory here. Anyone help me out?

Thanks a million, hugely appreciate any help

John

2

plotting RCin 1 (roll demand) and 4 (yaw), roll demand goes full negative at the same time as your yaw demand goes full positive.

Are you sure your radio is setup properly?

3

Thanks for the reply

Yes, the radio is calibrated correctly in mission planner. all sticks are registering as expected.

Could it be my PID’s?

4

The rcin are before any pid. I was going suggest looking at the cal page to check roll doesn’t move with yaw. I would take the props off and try on the bench looking at the motor speeds. Does it look like its trying roll and yaw at the same time when applying yaw stick.

sent from my phone so apologies for any typos