Toilet bowling naza

[powerlord]

Hmm...  Flying my quad today (modified f450 naza)  and demoed quad failsafe to someone,  and too my horror it started to toilet bowl and I panicked a bit and could get it into manual to then go back to atti to regain control.  It landed still toilet bowling but no damage.

I';ve never had this in the naza before.  Quite annoying.  Hopefully just a one off,  but as toilet bowling is usually a sign of magnetic interference I';m wondering if it';s worth degausing my gps??? And if so..   How?


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[Britishguy]

did you calibrate your compass, set the correct height in the naza assistant, offset your compass in either direct

[Hands0n]

Another possibility is atmospherics.  Given the amount of rain-laden cloud cover the UK seems to have there could be some attenuation of the more distant satellites.  Did you get any indication of low satellite contact in the IMU (the flashy light thingy)?

[Britishguy]

+1

[powerlord]

Yeh it had full sat lock.  And all set correct and calibrated (worked last time I tested it).  But I';ll calibrate it again.  I just thought I remembered someone talking about a degausing procedure?

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[Mudders]

I have read that toilet bowling can be cured by rotating the compass a few degrees, something to do with north/south hemispheres or something.

What values do you have for the compass in the mod box?

Muds

[Mudders]

Page 28 of the quick start guide v1.20 explains it.

http://www.dji.com/download/naza-m-v2-downloads/

HTH

Muds

[Hands0n]

That would be with regards Magnetic Declination, no? - it is supposed to change each six months or so (iirc) and also when you travel significant distances.   A pain in the ';arris when you';ve superglued the thing into place BEFORE reading that bit of the manual  which is what I did  

[Gav]

I';ve had my naza m v1 on my 450 with skids n gimbal, toilet bowl before when trying an autoland. It would also get into a toilet bowl cycle if just left hovering in gps mode?? I never ever really understood why it happened, but I';ve refitted things since and done the calibration a few times and also run 4s lipos now.  I never really pin pointed the one thing that cured it.  Was annoying at the time, but seems ok now?.

Come to think of it I was wondering if it was because the Z dimension on the x y z dims of my gps module were out with regard the c of g. You know you have to type in the position of your gps in relation to c of g in the software dont you. Anyway I checked that too.

[Balders]

any time I';ve had toilet bowl on naza it';s been because of magnetic declination, ie the arrow is not pointing where it thinks it needs to.

[Chami82923]

I have my GPS module rotated approx 3degrees clockwise from forward, i found by trial and error that this worked best to eliminate toilet bowling. (Re-calibrated the compass then done by just hovering in GPS mode)

Once i worked this out i drew a new North South line on the GPS so its easy to see if its offline.

This works for me at the locations i currently fly. I dare say that if i fly new locations the toilet bowling may reoccur.

Callum

[Hands0n]

Here is a quick demo of toilet bowl and the fix applied for Magnetic Declination.  Its an absolute doddle, the video tells it better than I';ve seen it written up anywhere

HTH

http://youtu.be/f6oDVQwUPwU

[powerlord]

yeh sorry maybe I should have been more clear:

regular gps flight - no toilet bowling.

control off : hovers on spot no bother.

RTH : toilet bowling

[Hands0n]

Ah, yeah but, no but, yeah    I don';t think degaussing the magnetometer is going to have any effect - as if that was the problem then you';d get toilet bowl in GPS-Atti mode too.    Something else is amiss, but I can';t think what it could be that would impact only RTL and not GPS-Atti. 

Possibly, a one-off software glitch caused by a spike in the power when plugging the LiPo in?
Possibly, some memory corruption at arming so it didn';t really know where RTL home was?

I';d say that the first thing to do is to see if you can reproduce the problem at will.

Before you fly though, I';d suggest to make sure you';ve set up the mode selection switch such that you can force the Naza out of RTL mode (iirc you need to switch to GPS then Atti a few times).

[Friskle]

with the phantom and my WKM, i have never had issues like toilet bowling, someone once said, whilst in the uk, there should be no need to have the GPS module arrow offset from pointing forwards, true or not i dont really know, but mines always been forward and never done it...yet at least.

it could also be noise interference, as the only issues i have had so far, is drift, or not totally coming back to where it should, but never to far to be much of a problem, what i did, was cut a piece of 1mm carbon sheet, grind to a circle approx 10mm larger thn the module and placed it between the mounting and the module, problems solved, and GPS locking in and GPS hover was far far better, the carbon disc is shielding the module from any possible electrical interference from the quad, tbh, the best thing i have ever done.

not saying this will cure your issues, but its certainly worth trying.