My first new P4 flight was in Minneapolis. my second one will be in Milwaukee today should I recalibrate the compass?

Yup. If you change locations, recalibrate it. I am pretty sure the instructions say that

Yes the instructions do say that and many people on the forums say you should not be recalibrate your compass if it's working fine. They say if you go far away to a different area to recal. I'm just wondering if this qualifies

I wouldn't bother over that distance, the inclination of the earths magnetic field won't change much since you are not moving very far north-south, I don't think the east west movement is as important since it doesn't affect balance, only direction.   

If you have a nice big green field with definitely no iron around then fine, but otherwise there is more risk from accidently recalibrating near metal than there is risk from the calibration being a little out for the location.

If it gives you a compass warning then it is more likely due to the area not being suitable for flying than a calibration problem so don't just recalibrate and then fly, find another location to try first.

Thanks Nigel from all of my reading I came to that conclusion too but I just wanted somebody that knows what they're doing to confirm

No offense meant to you Sean what you quoted was what the manual says and I believe I have read the manual enough times to know that so yes you are right but in practice many people do not recalibrate. Often

Shawn (sorry)

Just checked, and you are in an area where the magnetic declination map has a lot of contours as you move east-west, if you can find a good open place to recalibrate then it may be worth doing, especially if the aircraft doesn't seem as stable as it should be - move around slowly at low level for a bit after take off to check.

eliot may Posted at 2017-2-1 07:36
No offense meant to you Sean what you quoted was what the manual says and I believe I have read the manual enough times to know that so yes you are right but in practice many people do not recalibrate. Often

Hi , don't calibrate your compass until your prompted, I traveled from west of Ireland to Scotland 1500 miles, set my p4p on the ground and everything was perfect, more chance of getting bad calibration,
Enjoy the break, good luck

Calibrate it on EVERY single location change!

I only calibrate if I go over 100 miles from home. To each his own I guess. But I know I have ruined a good one before, when I was first flying because I would do it every time. Look at your compass readings, if they are not in the range they should be, you should do it. I think most will agree if you have a good calibration, don't mess with it. Again, to each their own.

adrian8891 Posted at 2017-2-1 08:47
Calibrate it on EVERY single location change!

Absolute hogwash and total misinformation, read the Manual.

Just let your drone warm up....It will tell you if cal. is needed.  If your Co-piolet tells you drone is ready for flying.....it is ready
If your home point is correct....you re ready to fly...."home point set, check your map"   If you hear this and your map shows your correct location....
you are set to fly..
If you have watched any of the thousands of how-to vids on internet.....They all seem to say calibrate every time you fly.....not true.
I calibrated my drone when I first fired it up and haven't had or needed to recal since then.
I go by what DJI recommends not some yo-yo on you tube.  If you have a problem you won't have much luck convincing a tech at DJI that
this was necessary.
Not all vids on you tube are yo-yo's. Some of these guys are very sharp.  Knowing who is legitimate and who is the yo-yo is just too hard to figure out so best to go with
what DJI recommends.  

RicardoGray Posted at 2017-2-1 09:02
Look at your compass readings, if they are not in the range they should be, you should do it. I think most will agree if you have a good calibration, don't mess with it. Again, to each their own.

I think the readings for compass interference have nothing to do with the calibration, except that it wont calibrate accurately if there is a lot of interference.  The calibration is to set which direction is north and which direction is vertical so that the aircraft knows when it is level and what direction it is facing.   If you move a long way around the world then the compass stops agreeing with the GPS which could cause confusion to the navigation system and also with a poor calibration it wont be able to maintain it's position accurately if it looses GPS which means that you wont be able to trust the traces on the map if GPS isn't working - bringing it back home without GPS or visual would be difficult.

Nigel_ Posted at 2017-2-1 09:22
I think the readings for compass interference have nothing to do with the calibration, except that it wont calibrate accurately if there is a lot of interference.  The calibration is to set which direction is north and which direction is vertical so that the aircraft knows when it is level and what direction it is facing.   If you move a long way around the world then the compass stops agreeing with the GPS which could cause confusion to the navigation system and also with a poor calibration it wont be able to maintain it's position accurately if it looses GPS which means that you wont be able to trust the traces on the map if GPS isn't working - bringing it back home without GPS or visual would be difficult.

You could very well be right Nigel. I guess I always thought if my readings were in the range they should be I was ok. You have more knowledge of how the compass works than I do for sure. So, the readings will indicate more or less interference?

I very much doubt it would make much difference over that distance as I've done much more E-W with no issues.
But the way to be sure is to launch and observe the Phantom.
Does it hover in place without wanting to slowly spiral?
Does it fly straight rather than attempt a big curve?
If that checks out you should be good to go.

I am a new to the world of drones and i must of been watching some 'yo yo' on YouTube and stated the compass calibration should be done on every flight and i have been doing that.

I didn't realise i was doing the wrong thing. Thanks for the advice.

You have to be careful if you are near Ley Lines. If you are then a quick spray of Homeopathic Compass Correction Fluid* will make sure all is fine. I always carry at least two bottles with me. Better to be safe than sorry.





*150ml spray bottle ony $59.99 + p&p on special now.

Cabansail Posted at 2017-2-1 15:53
You have to be careful if you are near Ley Lines. If you are then a quick spray of Homeopathic Compass Correction Fluid* will make sure all is fine. I always carry at least two bottles with me. Better to be safe than sorry.

How do you know if you are near one?  Is there an app to locate them or do I have to take my non-magnetic dowsing rods?

Nigel_ Posted at 2017-2-1 16:07
How do you know if you are near one?  Is there an app to locate them or do I have to take my non-magnetic dowsing rods?

Carbon Fibre Dousing Rods will help detect them.

A quick spray of HCCF will make sure you are safe. A bottle will last about 10 different locations.

Cabansail Posted at 2017-2-1 16:15
Carbon Fibre Dousing Rods will help detect them.

A quick spray of HCCF will make sure you are safe. A bottle will last about 10 different locations.

I would have thought a carbon fibre dousing rod would be impossible to make!  How on earth do you form the right angle bend in the rod, dousing rods don't work without the bend.  

Can't find any for sale...

Anyway, if the ley lines affected the compass then you would be able to find the ley lines using a compass and it has been well proven that you can't, you need dousing rods to find ley lines.

Cabansail Posted at 2017-2-1 16:15
A quick spray of HCCF will make sure you are safe. A bottle will last about 10 different locations.

Just spotted your avatar, are you selling HCCF made out of snake oil?

Nigel_ Posted at 2017-2-1 16:24
Just spotted your avatar, are you selling HCCF made out of snake oil?

No snake oil.

It has quite a bit of Hydric Acid.

Nigel_ Posted at 2017-2-1 16:24
Just spotted your avatar, are you selling HCCF made out of snake oil?

I wonder how many snakes you have to squeeze to get a bottle's worth.

And for the record, I would not worry about calibrating the compass unless there are issues while flying as stated earlier.

I like to re-calibrate ever one of my drones before every flight, so yes, I would re-calibrate even ever flight even if you fly in the same place.

KevDrones Posted at 2017-2-1 16:34
I like to re-calibrate ever one of my drones before every flight, so yes, I would re-calibrate even ever flight even if you fly in the same place.

Do you spray HCCF as well?

What is HCCF? Lol..

KevDrones Posted at 2017-2-1 16:38
What is HCCF? Lol..

Homeopathic Compass Correction Fluid

KevDrones Posted at 2017-2-1 16:34
I like to re-calibrate ever one of my drones before every flight, so yes, I would re-calibrate even ever flight even if you fly in the same place.

Recalibration of a perfectly working compass is totally unnecessary and puts you at risk of giving your Phantom a bad compass calibration.It doesn't make you safer at all.
Here's an example of a calibrate-every-flight guy coming unstuck because he calibrated in a bad location:  

KM5RG-Robert Posted at 2017-2-1 16:32
I wonder how many snakes you have to squeeze to get a bottle's worth.

As with all Homeopathic liquids, you dilute your snake oil until there isn't a single molecule in the bottle you sell, therefore you can make an infinite number of bottles from just one snake.

As he has already admitted in post #23, what gets sold is pure hydric acid  (chemical formula H20).

Nigel_ Posted at 2017-2-1 17:12
As with all Homeopathic liquids, you dilute your snake oil until there isn't a single molecule in the bottle you sell, therefore you can make an infinite number of bottles from just one snake.

As he has already admitted in post #23, what gets sold is pure hydric acid  (chemical formula H20).

It is not pure Hydric Acid. There is some other things in there as well including DHMO but it is quite dilute.

Okay, thanks for the info.

Cabansail Posted at 2017-2-1 17:52
It is not pure Hydric Acid. There is some other things in there as well including DHMO but it is quite dilute.

Too much DHMO (Dihydrogen Monoxide) will kill you. Gotta be careful with that stuff. I hardly ever get around it myself, and for some reason people hardly ever get around me either.

If the drone indicator on your map and on radar shows your drone facing the correct direction....Your compass is calibrated..
That's the fastest way to tell if you are properly calibrated.
Soil can give problems too if the soil is iron rich or has high Ferris content.
keep your eyes on that map and radar image...

After, I crashed should I recalibrate the compass, and I got a compass error saying compass is stuck then I reset it, and It worked.

Odan Posted at 2017-2-2 06:39
If the drone indicator on your map and on radar shows your drone facing the correct direction....Your compass is calibrated..
That's the fastest way to tell if you are properly calibrated.
Soil can give problems too if the soil is iron rich or has high Ferris content.

I always check if the direction is correct before taking off !

I would first give it a long warm up time. Maybe 4-5 minutes.  I would do this with the props off to prevent any flyaway chances.
Wait to see if your radar and map shows the direction that the drone is facing.
I would say that if both of these agree.....put the props on and just hover for a while.  Don't try and fly it anywhere.
If it has correct light on everything.....you should be good to go.
I would do this after any slight mishap as long as you aren't getting any further error indications.
Straighten up an fly right...

I only calibrate the P4 when it is away from the town, away from auto, away from wifi.  I usually calibrate it on the sand, away from metal objects. On the average, I calibrate mine about once evey month, but I keep a close eye and keep it at close range during the first flight after cal.

What if one has not used the P4 for a few months.  Should it be re-calibrated?
Common sense tells me no, but I still wonder.

adrian8891 Posted at 2017-2-1 08:47
Calibrate it on EVERY single location change!

not a good idea, I hope it all works out for you if you do.

even DJI no longer suggests that.

almost all lost phantom stories start with:
" I calibrated as usual before takeoff.........."

Been here reading the post for a couple years now and have owned/sold/have 6 phantoms.
My current P3P
was calibrated last March
rc is 1.6
DJI GO is 2.9.1 and I have real maps

Good luck and have fun flying