The Compass Calibration

[AndyH]

To view this content we will need your consent to set third party cookies.
For more detailed information, see our cookies page.

Accept third party cookies

I've read many different opinions on compass calibrations. One of my questions while trying to get to know my aircraft is that where exactly do you know where to calibrate the compass without any negative influences. Would it be the obvious wide open field? I had a scary experience that I beleive that may have been influenced by an incorrect compass calibration. I posted on a previous thread and someone noted that according to my location the magnetic north is 14° shifted. The more I read up on it, the more confused I get. I'm posting a link to a recording of the flight path that I had from my OS moment. It's sped up a lot but anything after 3:22 ish is completely uncontrolled flight. My (seriously lacking) pre-flight checklist didn't include double check multiple flight mode and it wasn't enabled.
I got EXTREMELY lucky that it landed unharmed.

 

[turbodronepilot]

Hey Andy...
welcome to inspirepilots.com. ..
If you fly out of your residence I'd find a spot on your property that is away from anything that could cause interference and try and calibrate your compass. .
if you don't fly out of your residence then do it in your favorite flying spot...
once you go through the calibration process then start up your i1 and check your mod values. .
if they check out then take it up and away around 100 feet and then hover ..if it hovers in gps and is stable and your pointer in your radar is pointing the same direction as you and your inspire1 (then test your rth to make sure it heads the rite direction ) then id say you have a good calibration so stay with it until your next firmware update or if you move great distances. ..
if you move somewhere and your mods or pointers don't look rite then move around 20 feet and start it up again and check your mods ..
if you move a few times and your pointers don't line up or your mods are out of wack fly somewhere else..
one place I fly if I calibrate my compass my pointers won't line up..but if I don't calibrate and fly that spot it's all good..
the way you get a bad calibration is from calibrating in a bad spot...
Make sure you did your initial imu calibration after receiving your i1 from China or after a firmware update then calibrate your compass ..
then you should be good to go....
turb...

 

[turbodronepilot]

Also make sure and use a screen recoding device and a gps tracker ..

 

[AndyH]

Have the Tracker, though it was in my pocket during that flight (I guess I could track my pants at least). The compass does point correctly after my last calibration though it does seem a little off. The direction is good. I had completed a short flight just prior to that one on the same battery. Does that matter?
Prior to that flight I calibrated the IMU at that location. The surface may not have been perfectly level. Learned my lessons though. I was just wondering if experienced pilots think that flight track was caused by compass error. It also went to 500 ft on its own. I'm positive that it was at 350 when I lost complete control.
Thanks for your input and information, looking forward to learning as much as I can about the aircraft.

 

[turbodronepilot]

Have the Tracker, though it was in my pocket during that flight (I guess I could track my pants at least). The compass does point correctly after my last calibration though it does seem a little off. The direction is good. I had completed a short flight just prior to that one on the same battery. Does that matter?
Prior to that flight I calibrated the IMU at that location. The surface may not have been perfectly level. Learned my lessons though. I was just wondering if experienced pilots think that flight track was caused by compass error. It also went to 500 ft on its own. I'm positive that it was at 350 when I lost complete control.
Thanks for your input and information, looking forward to learning as much as I can about the aircraft.

The imu calibration should be done at home on a completely level surface ..
you only need to calibrate the imu after getting your i1 from China or after a firmware update or after a heavy shock..
this might be the cause of your crazy flight along with a bad compass calibration. ..

 

[lake_flyer]

My Pilot App always says I need to calibrate the compass. But I seldom do. After a good calibration I leave it like it is for as long as I can. I would only calibrate after a FW update, or travel like 100 miles or more. Or when I see a bit of toilet bowl effect. Calibrating in the field always poses the risk of hidden influencers.

Turbodrone is right about IMU calibration.

 

[AndyH]

When I re-did my IMU calibration I actually used a spirit level across the tops of the motors.
I'm not sure if I have to recalibrate again though since I had to do another update because of a new battery. It really doesn't matter to me since it's not any real inconvenience. Am I missing something when I calibrate the RC? All I get is little circular arrows with full 100% stick motion. Is there more?

 

[LockMD]

Am I missing something when I calibrate the RC? All I get is little circular arrows with full 100% stick motion. Is there more?

Don't forget to do the wheel for the camera. It won't complete the calibration without doing it.

 

[AndyH]

Aha. That did it. Thank you!

 

[AndyH]

So I've had a few really low level flights recently but. ...quite frankly I'm afraid to go above 90 feet or so. Not until I find a very, very reasonable explanation of what happened. I can't let 3G's just fly away or potentially injure someone.