Compass calibration, course lock....

[Hotrod]

..I am still fairly new at the Phantom hobby. I admit I got a lot of my "training" from watching YouTube. I was under the impression that you were supposed to do the "dance" every time before flight, but always for sure after changing location. Now I read that that is just asking for a problem. What is the prevailing wisdom?

Also, maybe a dumb question, but here goes....Assuming the craft is in GPS lock and I then switch to IOC (course lock) is it still using the satellite,s for stable flight and finding home. What if I am using "return to home" function? (sw2 down)
The reason I ask is that my last crash was when I was using return to home in NAZA mode. As the craft approached within maybe 20 ft out and 10 ft high it suddenly did a "falling leaf" impression and damaged my gimble among other things. I have been afraid to use that mode since then, but have had no more problems while flying in GPS mode.

 

[Idbird]

Compass calibration is not needed before every flight. As a rule, if you change flight locations >30 miles, it is recommended to do a recalibration.

Yes, your bird uses GPS in IOC, Homelock, and RTH. The latest firmware update really slows down the decent rate, which should prevent some VRS occurance. I prefer to take back control in GPS Lock to land. Hand catching the bird and pulling the throttle all the way down will also prevent tip overs.

I hope this helps!

 

[Nathan Carter]

As the craft approached within maybe 20 ft out and 10 ft high it suddenly did a "falling leaf" impression and damaged my gimble among other things

That is completely NOT normal, and should not happen in any mode. Eventually if it somehow managed to enter "manual mode" but prerequisite for that would be malfunction of S1 switch(The one on the right where you switch GPS, ATTI and FAILSAFE or MANUAL). But if you programmed that switch on the computer in the Assistant software to be FAILSAFE(return to home) instead of MANUAL, even that could not happen. Did you do that? Did you test that it works?

Other than that it must be some sort of hardware malfunction, either your battery contacts or one ESC(small electronic board, there is one for each motor) or one of the motors is failing. ESC/motor problems could be possibly spotted if you see that speed of one of the propellers is not the same(on the ground) or when stopping the motors that one propeller is stopping relatively sooner than the others. Also check that when you are turning the propellers by hand that they all turn equally smoothly and that after a flight the temperature of each motor is roughly the same.

Another question, is this a new unit or second hand? In both scenarios, did the craft had some crashes before?

 

[Hotrod]

It was a new purchase from Amazon. It has had one other fairly serious crash, something that was my fault. However it flew very well this last weekend when I took it to a location about 30 miles away. I did the "dance" and it flashed the rapid green led,s showing that it knew where home was and away it went. It did put a message into my smart phone asking if I wanted to set the RTH altitude while I was in mid flight. I have never seen that before.
I too prefer to hand catch my drone, it is too easy to tip otherwise.
Thanks for your advice.

 

[Nathan Carter]

It has had one other fairly serious crash, something that was my fault.

This is important! So before this incident you had a crash, nonetheless a serious one as you describe.

That could cause a multitude of problems. You could have a connection inside your phantom that is loose now. Even soldered connections could have come loose during impact. So something got loose but is still connecting/touching and then under some conditions(vibrations) that comes off loose. For example connection to one of the ESC boards or even main power from battery.

You must open your shell and visually verify all connectors and soldered points of contact between different electronic boards inside. Otherwise you are risking having another incident in the future.