Andy Theimer's Posts (1)

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After numerous bench tests, re calibrations, and more bench tests I was finally brave enough to take my 3DR quad out for it's first flight -albeit tethered.  I did some initial outdoor ground testing in which I brought the throttle up to the point of takeoff but noticed that the quad was showing a tendency of tilting forward and right so I killed the throttle, ran this test several times, and decided I didn't want to attempt the takeoff having no clue what might happen. So...

I threw together a quick test rig on nearby deserted swingset to evaluate what the quad would do when in the air.  The video clip below shows the outcome... Without any stick input the quad wants to fly forward and to the right.  I was able to counter it with stick movement and fly the quad around the rig without too much trouble but if I stopped countering the roll/pitch it would try and wander (this is evident in the video when you see it start to move sharply to one side).

I've ruled out motor rotation, wiring, and prop direction via another round of tests to verify everything's good.  That leaves me suspect of:

  • mis-calibrated radio
  • mission planner radio calibration
  • Radio Trims?
  • Leveling (although I leveled before this flight)
  • Auto-Trim (I've done none of this yet)

I also found the following in a FAQ post:

"My copter yaws right or left 15° when I take off: Your Motors are not straight or your ESCs are not calibrated. Twist the motors until they are straight. Run the ESC calibration routine."

I've calibrated the ESC's many times over the learning process how often should I need to re calibrate them?  As for motors not being straight... I've checked that they're secured properly to the frame, not sure what could be off.

UPDATE:

I originally posted this in the Forums and got some great advice but I thought I would consolidate and put all my experiences on a blog.

The solution for me was a simple radio re-calibration on the TX(er9x) and then a re-calibration of the radio in Mission Planner.  Finally ready for some flight!

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