Great first flight but got drift

[Findtheriver]

T First flight of f450 happened at lunchtime today (finally got into compass calibration mode on dx6i!). All went well in GPS mode except I have a drift of about 4 foot before it settles into ps held hover. Is this c of g issue or should I re-calibrate?
i thought I had balance the quad quite well with battery across the chassis (running left to right rather than front to back)

 

[kloner]

with small motors cg is everything. hold two opposing arms, balance, hold other two, balance, should be balanced on all axis flat and level. Then the ATTI gains will have a pretty big influence on how gps mode works, how tight or loose it is.... loose it won't get to the spot your trying to get to, tight it'll circle around like water in a toilet bowl looking to stay still to perfectly set it should kinda agresively stay put to a degree..... the bigger benefit to gps flying is in forward flight you don't have to correct for wind hitting it from the side blowing straight ahead off course. The position hold is always a hit and miss thing depending on winds.

 

[Findtheriver]

Thanks kloner that makes sense. I think I may have been a little too approximate with c of g! I haven't touched the gain settings on assistant! What should I start at?

 

[kloner]

the gains should remain close to default, forget what that is now, but it's usually really close. Easiest way to adjust gains is to put them on a knob or slider on the radio. i use one channel for manual gains, another for atti gains and i move them proportionately unless an axis shows a sign of under or over gain...... a dji controller should seem very locked in and solid, anything less is bad gain or bad mechanical problem like a motor bearing being bad, prop out of balance, etc.

 

[kloner]

this was bone stock gains dialed in on a first hop from a dial on the tx. see the stability, if your seeing anything less, look for heat when it lands in motors or esc's..... i've seen alot of stock motor/prop not work real well from broken/bad balance even new out of the box....

 

[rilot]

What flight controller are you using?

 

[photobobga]

Kloner and Findtheriver, My experience has been that getting the NAZA FC with GPS to hold 'spot on' without any drift is not the norm. A well balanced multirotor will drift somewhat during the first few minutes of the flight and then settle in as the flight progresses. As Kloner stated, using the GPS option during a flight will help in tracking as the aircraft travels. What I found during my first few months of learning to fly the NAZA FC multirotor the GPS gave me a scene of security when I needed it. Now after many months of flying and learning the differences in the DJI Assistant setting I rarely fly in GPS, mostly in ATTI or manual mode. I changed the ATTI setting down so that they are less likely to cause quick movements during my flights. I regard Kloner's replies on this forum as being the most accurate and worth reading. Thank you!

*Bob

 

[kloner]

we've been flying science instruments on a naza based hex with ground station,,,,, we nail waypoints usually about 70-80% of the time..... the payload kinda has alot to do with what we see too, it's not conventional... my atti gains are somewhere around 90 but there on a dial and i try messing with it during flight to tickle it into stopping somewhere.

Thanks

 

[cootertwo]

kloner, what you all up to there? Looks interesting.

 

[kloner]

darpa project

I get myself into the weirdest stuff

heres another

 

[Watchkeeper]

That's amazing kloner!

 

[kloner]

thanks, you get into this stuff it'll take ya places

 

[photobobga]

Damn.. I don't impress that easy but that was just way cool! Thanks for sharing. The large white disc on top... GPS?

 

[kloner]

Yea, whats that called with one on the ground and one using it for reference? that.... 4 cm accuracy on everything it records to a point cloud

I seen those gps systems in micro form at kickstarter.... arduino based i think. Theres alot of fun stuff coming with the uav bill getting closer and closer

 

[OneStopRC]

Kloner, that video is amazing... Still trying to pick my jaw up off the floor. Very interesting and very detailed indeed. Thanks for sharing that.