HedgeTrimmer Posted at 3-5 07:52
Leave it to you to find some way to dismiss point of his post.  Point is drones are not as sensitive to magnetic field as you keep hyping based on your Internet Lore.

As far as lecturing me on "no [sic] very little"; I was not one who claimed 25-degrees was 1/4 turn.

As regards 1/4 turn, call it what you want, but I actually apologized for the mistake I made, something you keep forgetting to mention.

AlansDronePics Posted at 3-5 07:29
I will watch the links you provide. Thank you.
No doubt you will notice I suggested to Hallmark that he came up with a real experiment to try and narrow the discussion. The suggestion is open to everyone to contribute to this, not just to burden Hallmark with it. So, please feel free to read the post and suggest a conclusive, repeatable experiment.
I did discover the dual compasses in the MP when I moved the magnet on my knife blade around.

Yes!   But it is hard to get to truth when we have a person who continually dismisses any work or testing; because he thinks he knows it all based on Internet Lore, and supposedly taking a drone class to supposedly get a commercial drone license, to supposedly fly commercially.

In the past, I have asked several pilots who have experienced compass problems as a possible result of magnetic interference - if they could  to go back and check takeoff point for a source of magnetic interference.   Hoping to determine whether their drone was effected by a hidden source (buried power or steel) or compass suffered a problem in flight.

hallmark007 Posted at 3-5 07:29
I think magnetic interference on a compass is without any doubt going to cause a problem for compass and I’m certain they’re are many many tests to prove this. To say magnetic interference has no effect on a compass is completely ridiculous.

Come on Hallmark, when you are in a hole stop digging!
I never said magnetic interfence wouldn't affect the compass. It does, I showed this. Other video with magnet attached shows it does not cause erratic flight. The magnet was there at takeoff and MUST have a stronger magnetic flux than a layer of reinforcement or a buried pipe or cable.

What you have singularly failed to demonstrate scientifically is that mag int is the cause of the drome flyaways.

You will notice from my half assed video, that the overloaded drone sensor does quickly restore itself when a powerful magnet (compared with earth) has no lasting effect.

Not only that, you haven't suggested a convincing experiment, either.
How many oportunities to prove you are right do you need?

hallmark007 Posted at 3-5 07:32
You again no very little so please refrain from commenting on my posts.He didn't tape any magnet to his drone, that was skunkworks a good friend of mine .

You aren't doing yourself any favours Hallmark. People here want to know the truth, so do I. All you want to do is pontificate.
I am disappointed with you unsupported assertions.
I am prepared to carry out a reasonable experiment to lay this matter to rest. No risk to you, but you still think a rebuttal is enough to prove your point.
People here won't respect you if you can't prove what you assert. I am only trying to find the truth.

AlansDronePics Posted at 3-5 07:46
No, Hallmark, that is not fair!
I won't take unnecessary risks when they could impact other people, here on the island.
Like the person in one of the videos I included, he wasn't prepared to hunt for his drone if the magnet caused the drone to crash. Even in sensor mode, his short flight shows clearly the drone wasn't affected.

You are wasting your time.  We all know he is:

all-mouth

AlansDronePics Posted at 3-5 08:02
Come on Hallmark, when you are in a hole stop digging!
I never said magnetic interfence wouldn't affect the compass. It does, I showed this. Other video with magnet attached shows it does not cause erratic flight. The magnet was there at takeoff and MUST have a stronger magnetic flux than a layer of reinforcement or a buried pipe or cable.

I don’t need to scientifically prove anything just like I’m sure jjb Labroids slump and many other experienced users don’t have to, I’m not a scientist, but I have experience of compass both from sailing and flying drones, I know what occurs when compass is interfered with and I can determine where it came from by looking at coordinates and from user who was flying, I can also compare to many many other flights and logs I’ve seen, I can also say that many more experienced users here share the same views, I also have some experience of building drones with my father, I don’t come to this ignorant and I don’t have another explanation, it’s not a conspiracy we are peddling here, but a true knowledge and experience.
But I always find that those like yourself and Hedgetrimmer, stone throwers I’ll call you always know what everything isn’t , but almost never know what is .

So if you can tell us what caused OP’s drone to YAW OUT OF HIS CONTROL then be my guest .

Hi. I am sorry for the trouble this has caused. With regards to this concern. Please try flying the drone in a different location with less interference like metals, power lines or radio towers. May I know what mobile device you are using when you are experiencing this issue? Please try to put the mobile phone to airplane mode to isolate the issue. In addition, I will be posting an official DJI Video Tutorial for the best practices when flying the drone. Please keep us posted for further assistance. Thank you.

hallmark007 Posted at 3-5 07:52
Go do what you please come back and be the hero, I think anyone who can’t even get his drone to connect then goes a smashes it into the ground through temper is not one I can hang faith in, we shall wait and see hopefully weather improves soon .

To be correct, Hallmark, my frustration was due entirely with DJIs attempts to fiddle with the MP firmware to the extent NFZ messages were constantly blocking the screen and preventing them from being answered. Folks reading this, I live on a small Island and permission to fly is arranged with ATC. There is an area where I don't need permission at all, but  the NFZ from France prevents ALL flights. The only way (then) was to answer their messages. Also the current series of firmware, back then, lead to all manner of unstable flights and were recorded on this forum.
Yes, I tossed the ****** thing away, because it was a dangerous device to fly. About a year later, the crashes stopped happening and I started flying the MP again. I have 2 and a P3P.
I use No Limit Drones firmware and software and have never had a single problem with it.

I have no wish to be any hero. I just like to know the truth. I will still avoid all suspect situations, so I am not misleading anyone.

Hi all,

My name is used it post #46 but not correctly for the conclusion of this fly way.

I never said anything about interference etc so the conclusion "a fly away due to compass" is correct, not correct is my opnion if interference is the cause of it. (wich i do not know)

If compass is interfered (showing a other heading than the acual heading and/or msg in the app), this deviation is normally away after take-off. Question than is if this will cause a fly away as mayby other yaw signals in the FC are disturbed as well. What we see sometimes is a fly away after many many minutes in flight....Due to this kind of interference at start-up ?

My guess is that the compass heading was not the actual heading, and did not change after take-off. See the data in log.Why do i think this is the case? while when the drone moved away a little things started to go wrong.
What happend is that the FC start to correct the drone to keep position it will given signals to the wrong motors, resulting a fly away as in this flight, amount of compass heading offset will make the 'radius' of the TBE move.

This is the only fly away, we as 'pilots', can prevent ; just by simply checking the compass heading on the ground set to actual heading.

cheers
JJB

So, no one can devise a robust experiment to uncover the truth about magnetic interference affecting drone flight or not?

AlansDronePics Posted at 3-5 08:21
To be correct, Hallmark, my frustration was due entirely with DJIs attempts to fiddle with the MP firmware to the extent NFZ messages were constantly blocking the screen and preventing them from being answered. Folks reading this, I live on a small Island and permission to fly is arranged with ATC. There is an area where I don't need permission at all, but  the NFZ from France prevents ALL flights. The only way (then) was to answer their messages. Also the current series of firmware, back then, lead to all manner of unstable flights and were recorded on this forum.
Yes, I tossed the ****** thing away, because it was a dangerous device to fly. About a year later, the crashes stopped happening and I started flying the MP again. I have 2 and a P3P.
I use No Limit Drones firmware and software and have never had a single problem with it.

I don’t believe I’m misleading anyone or neither do I believe jjb or slup is trying to mislead anyone, but I do know that many many mechanics don’t know exactly scientifically how everything in a car works , but they can still tell if it’s broke and experience is just as much part of their job as anything else , it’s very easy to throw stones without having a solid opinion backed up by anything, and I’m afraid your tests above prove nothing except to say compass is effected by magnetic interference,

There are many who go to great lengths to help others here through their experience, but it’s very easy for you and Hedgetrimmer to come along and say it’s wrong because you think it is .

hallmark007 Posted at 3-5 07:58
Tell that to anyone who has crashed recently, and incidentally skunkworks who on another thread you ridiculed for his magnetic test of Remote Control crashed his drone while flying across a metal bridge because of magnetic interference.

It’s strange that you decided to answer my post while Jjb opinion was exactly the same as mine, I suppose he’s totally wrong in his summation of “a crash we normally see around here”

See you are back to using your Troll-n-Trash tactic of trying to turn one member against another.  Problem for you hallmark007, is you are well known for putting words in other people's mouths.  Another common Trash-n-Troll tactic of yours is to call others out.  Followed by blanket dismisal of evidence and proof provided by person you called out.

This time you have been called out.  So put up or shut up.  Don't bother posting videos made by others.   Make your own video, and be prepared to defend it.

Hi and thanks everyone, I usually calibrate the compass when the DJI FLY APP ask me to do that, the take off point is in front of my house and I take off from here for many times without any problem.

I've to admit that I haven't checked the compass position and orientation before take off, my first mistake I'll take more attention about that.

Thanks a lot
This is a very helpfull comunity

Bye

AlansDronePics Posted at 3-5 08:07
You aren't doing yourself any favours Hallmark. People here want to know the truth, so do I. All you want to do is pontificate.
I am disappointed with you unsupported assertions.
I am prepared to carry out a reasonable experiment to lay this matter to rest. No risk to you, but you still think a rebuttal is enough to prove your point.

I can prove and I have many to back me up on what I’ve said, but I see almost nothing from both you and Hedgetrimmer except to throw smart remarks from the side, everyone around here knows Hedgetrimmer favorite pastime is around here is trolling me .

JJB* Posted at 3-5 08:25
Hi all,

My name is used it post #48 but not correctly for the conclusion of this fly way.

I follow your reasoning and it on that basis, it seems logical.
You like to solve the puzzle of the numbers. I am curious about fly-aways and their cause.
In that respect, I think we are both looking for the same truth.
If the magnetic aspect is so critical to the flight, surely it should be repeatable in an experiment?
I have never knowingly taken off from a magnetically disturbing area, and probably never likely to. But I am prepared to conduct a reasonable experiment to see the effect.
Based on your Log observations, how would you see the circumstance that would lead to a repeatable outcome?
Ideally, I  would prefer to tether the drone when taking off from a bunker or fly within a quarry so the drone is contained. From what I have seen in posts, flyaways tend to stay at a fixed altitude. Is this something you have noticed?

hallmark007 Posted at 3-5 08:29
I don’t believe I’m misleading anyone or neither do I believe jjb or slup is trying to mislead anyone, but I do know that many many mechanics don’t know exactly scientifically how everything in a car works , but they can still tell if it’s broke and experience is just as much part of their job as anything else , it’s very easy to throw stones without having a solid opinion backed up by anything, and I’m afraid your tests above prove nothing except to say compass is effected by magnetic interference,

There are many who go to great lengths to help others here through their experience, but it’s very easy for you and Hedgetrimmer to come along and say it’s wrong because you think it is .

"it’s very easy to throw stones without having a solid opinion backed up by anything, "

Said by the stone slinger of all time.  


Who refuses to admit he was/is wrong.  Who refuses to apologize.  

After having thrown stones, calling some one out, and been provided with ample proof.

calling his bluff

Result was hallmark007 further claiming proof present was fabricated.

bogus dismissal

I think everybody can see clearly here hedgetrimmers refusal to talk about the topic, so being totally off topic once again. The reason he does this apart from trolling is because he knows nothing and as others keep repeating he’s way out of his league here.

hallmark007 Posted at 3-5 08:33
I can prove and I have many to back me up on what I’ve said, but I see almost nothing from both you and Hedgetrimmer except to throw smart remarks from the side, everyone around here knows Hedgetrimmer favorite pastime is around here is trolling me .

Yap, yap, yap.  All Talk and No Trousers.   
Where is "your" proof?  Again, don't bother with other people's videos or write-ups.

JJB* Posted at 3-5 08:25
Hi all,

My name is used it post #48 but not correctly for the conclusion of this fly way.

Respectfully, I think you mean #46.
I never mentioned you.
Thanks

hallmark007 Posted at 3-5 08:48
I think everybody can see clearly here hedgetrimmers refusal to talk about the topic, so being totally off topic once again. The reason he does this apart from trolling is because he knows nothing and as others keep repeating he’s way out of his league here.

"I think everybody can see clearly here hedgetrimmers refusal to talk about the topic, so being totally off topic once again."

But of course, it is perfectly acceptable for you to go off topic.  Then cry foul!
In fact, you have a habit of intentionally side-tracking and derailing threads, to Trash-n-Troll.  Especially, when you have been shown to be B.lowing S.moke.  Then it's off to whiny-ville.

You say you can provide proof.  Provide "your own" proof.

JJB* Posted at 3-5 08:25
Hi all,

My name is used it post #48 but not correctly for the conclusion of this fly way.

Hi JJB.

You can thank DJI fan-atical boy, hallmark007.   

He is using his old tactic of trying to pit one forum member against another.    Frequently done by putting words in other members mouths.   

Cheers!

JJB* Posted at 3-5 08:25
Hi all,

My name is used it post #48 but not correctly for the conclusion of this fly way.

You’ve obviously set HT off on a tangent looks like he’s hitting the self destruct button again.

But on topic and from what we have seen particularly of late it is most likely that compass was interfered with and I would hazard a guess it was magnetic interference, not manual.
Read both these posts they are extremely similar.

https://forum.dji.com/forum.php? ... 519&pid=2080202
https://forum.dji.com/forum.php? ... 519&pid=2080635

AlansDronePics Posted at 3-5 08:50
Respectfully, I think you mean #46.
I never mentioned you.
Thanks

I think if you read this case which is almost identical and it was also same conclusion that poster came to here on this thread, it’s fully backed up by proper logs both device and .dat log same log as dji would work from.
Read both posts and conclusions by poster.

https://forum.dji.com/forum.php? ... 183&pid=2099579
https://forum.dji.com/forum.php? ... 519&pid=2080202

AlansDronePics Posted at 3-5 08:26
So, no one can devise a robust experiment to uncover the truth about magnetic interference affecting drone flight or not?

https://forum.dji.com/forum.php?mod=viewthread&tid=209328

I think you should also read this thread completely, you will see that although some didn’t agree that crash was a result of magnetic interference, that conclusion from DJI WAS CRASH WAS CAUSED BY MAGNETIC INTERFERENCE.

You will also find if you compare all 3 you will find that they are almost identical, also you will find because drone does not report direct to app dji will now offer warranty for this type of malfunction .

luca6686 Posted at 3-5 08:31
Hi and thanks everyone, I usually calibrate the compass when the DJI FLY APP ask me to do that, the take off point is in front of my house and I take off from here for many times without any problem.

I've to admit that I haven't checked the compass position and orientation before take off, my first mistake I'll take more attention about that.

Your welcome, keep safe and fly safe .

AlansDronePics Posted at 3-5 08:50
Respectfully, I think you mean #46.
I never mentioned you.
Thanks

yes, #46    numbers did change after writing my text.

cheers
JJB

hallmark007 Posted at 3-5 09:05
You’ve obviously set HT off on a tangent looks like he’s hitting the self destruct button again.

But on topic and from what we have seen particularly of late it is most likely that compass was interfered with and I would hazard a guess it was magnetic interference, not manual.

"most likely that compass was interfered with and I would hazard a guess it was magnetic interference"

Where others have tried, worked, and tested - we get  "hazard a guess"  

the Pontificator - "I can prove and I have..."

hallmark007 show us "your proof", which you said you had!

AlansDronePics Posted at 3-5 08:42
I follow your reasoning and it on that basis, it seems logical.
You like to solve the puzzle of the numbers. I am curious about fly-aways and their cause.
In that respect, I think we are both looking for the same truth.

Hi Alan,

Yes, this log is not hard to understand, compass offset to the actual heading is the cause of correcting signals to the wrong motors.

Big question is :  why did this compass was offset ?  due to magn interference or due to ??
Or was the compass OKE and the yaw reference signal out of tune in the IMU?  

I do believe that magn interference has effect on the compass, but after out of influence height compass is OKE again. So if people say; in a 14 minutes flight when there is a fly away "must have picked up a interference at the takeoff spot"  I cannot believe/explain that this is possible.

Experiment ; fly multiple same flights same flight patron takeoff from magn inteference spot (msg in app)  and log what happend....

I had 3 times a large compass fail during flight with my SPARK; into ATTI !  And all 3 flights takeoff from from a free of any magn interference open green field. And in all 3 cases an "inflight repair", SPARK brought under control in ATTI and craft into PGPS mode.

Why should a craft in a fly away not stay at its flying height?  Up/Down is not used for correcting position.

cheers
JJB

JJB* Posted at 3-5 08:25
Hi all,

My name is used it post #48 but not correctly for the conclusion of this fly way.

I read the OP again and also some links Hallmark pointed to.
OP said, "so I take off, but after few second of upward moving, made by me, mini start to go left very rapidly and then I've lost signal, then the drone start the Go Home procedure and come back straight forward, than I've got signal back and I've rapidly landend."

Other links show the instability seems to happen some way away from the TO point and some time later.
Regarding the height. From your explanation, I can understand that free of the mag inf at the TO point, the drone would sense the earth mag field. It is at this point the internal confusion is believed to occur. That sounds sensible. However, why does stick control fail? Even if the drone doesn't know which direction it is facing, what stops it going in some direction, or up or down. Even if it starts to circle, toilet bowl, the compass recovery is very quick, no more than 2 or 3 seconds. I refer to my tests with the compass swamped with a nearby magnet. So, with an accurate compass, GPS and IMU in agreement, because of the rotation, why can't any stick control be seen?
The OP also said he lost signal (Contact). That would explain why he couldn't control it with sticks, but others reported the drone just kept flying away. Why don't those drones behave when the compass and IMU and GPS agree?
In the OP case, the RTH was the trigger that regained control. If the drone was still confused, how could it find its way home?
Why don't the full flyaways respond to RTH?
I see no compelling explanation for magnetic interference causing sustained loss of control but I do see a good reason to blame a software or processing glitch.
These so-called flyaways are not statistically frequent, taken in the context of the number of drones that have been purchased. We see a lot on the forum (comparatively) because, like a car repair shop, you usually find a faulty car there. Stands to reason. There are so many people taking off from city carparks or similar magnetically disturbed areas and lots of people do fly successfully near bridges, ships and trains that statistically, I would have expected many more flight issues.
What is your view on that?

What are your views on this?

What would you say are the key factors that would guarantee a confused and toilet bowl senario?

hallmark007 Posted at 3-5 09:05
You’ve obviously set HT off on a tangent looks like he’s hitting the self destruct button again.

But on topic and from what we have seen particularly of late it is most likely that compass was interfered with and I would hazard a guess it was magnetic interference, not manual.

uh Hallmark?  what is wrong with you?   one post you state that you do not think that Slup, others and I not trying to mislead people... GGood observation, well done!  
Speaking out for for myself; you are absolutely right!

And now i am hitting a self destruct button?  Just because i say i don`t know about the real cause?But its fun to see how you try to get support from others to help your 'fight' with people who are 'against' you.

cheers
JJB

AlansDronePics Posted at 3-5 10:04
I read the OP again and also some links Hallmark pointed to.
OP said, "so I take off, but after few second of upward moving, made by me, mini start to go left very rapidly and then I've lost signal, then the drone start the Go Home procedure and come back straight forward, than I've got signal back and I've rapidly landend."

I did ask you in an earlier post to read post #9, you also are under the impression that the OP had no control of sticks, if you look at flight log you will clearly see that all stick movements by OP fully registered on the drone and clearly shown in flight log.
You will also see in other examples shown same thing drone obeys commands of controller.
The problem is heading is not correct because of what occurred on the ground , video will clearly explain, and incidentally Mad RC is an engineer with a huge amount of experience with drones.

Hello Luca6686:

Heads-up about following:

Raise AC to height of 8ft
Hover for 20 seconds
Fly forward 2ft
Backward 2ft
Left 2ft
Right 2ft
Up 2ft
Down 2ft
Yaw left
Yaw right
Each time returning to hover position
If you have a good horizontal each time, you will then know you have good GPS good IMU and good Compass, and your ready to fly.

The Raise hover, fly forward/backwards left/right up/down, and yaws returning to hover with good horizontal each time - does NOT mean you have "good Compass" and you are "ready to fly".  You absolutely have to verify drone's compass is pointing correct direction.  Don't skip over it.  


The Raise, hover, and fly (above test) does little more than verify drone is responding correctly to Joystick input.  You would be better served by raising drone over 1-meter in height, rotating drone 90-degrees at a time, and verifying drone's compass agrees with direction drone is pointing at.

We have seen at least one case, where pilot performed the Raise, hover, and fly (above test), and there was no indication of problem.  Yet, the drone's compass was well off, and drone crashed.  Pilot should have verified compass was pointing correct direction prior to take off.   The Raise, hover, and fly (above test) can give pilot a False sense of safety.


Overall pointing being, the Raise, hover, and fly (above test) alone does NOT mean you have a "good Compass" and you are "ready to fly".  There has been no evidence provided, the Raise, hover, and fly (above test) does any good.

JJB* Posted at 3-5 10:11
uh Hallmark?  what is wrong with you?   one post you state that you do not think that Slup, others and I not trying to mislead people... GGood observation, well done!  
Speaking out for for myself; you are absolutely right!

I think you should go read my post again, I never said you were or had hit the self destruct button. But it might require you reading other posts.

I think it’s clear where the support lies here.

AlansDronePics Posted at 3-5 10:04
I read the OP again and also some links Hallmark pointed to.
OP said, "so I take off, but after few second of upward moving, made by me, mini start to go left very rapidly and then I've lost signal, then the drone start the Go Home procedure and come back straight forward, than I've got signal back and I've rapidly landend."

However, why does stick control fail?  stick control did not fail, in this kind of fly away it is possible to steer and get the craft in control ( but difficult as craft accelerates and is often relative far away to visual see which steering has the right effect )
But the OP did not do that, see the chart.
At ID 290 started to move, and just shortly left stick and yaw right was applied.


Even if the drone doesn't know which direction it is facing, what stops it going in some direction, or up or down. Even if it starts to circle, toilet bowl, the compass recovery is very quick, no more than 2 or 3 seconds.
Look at the heading chart, yaw and reference yaw are equal, so compass hdg did not change after takeoff, so offset remains there thus sw keeps op steering ; TBE move.


The OP also said he lost signal (Contact).
Because of this connection loss MM into an automatic RTH. I cannot explain but i have seem more compass fly aways where hitting the RTH button the craft heading and yaw signals come together again. In this flight the same, RTH in a straigh line towards home. So not because of OP doing the right action, but because of the OutOfControl initiated RTH.


...see a good reason to blame a software or processing glitch...
I have no clue if this is the case.  DJI sometimes refund in full in such cases, where we all think  user error beacuse of taking off from metal roof of a car or nearby a car  or nearby a bridge etc.


These so-called flyaways are not statistically frequent, taken in the context of the number of drones that have been purchased. We see a lot on the forum (comparatively) because, like a car repair shop, you usually find a faulty car there. Stands to reason. There are so many people taking off from city carparks or similar magnetically disturbed areas and lots of people do fly successfully near bridges, ships and trains that statistically, I would have expected many more flight issues.
What is your view on that?
How many drone are sold worldwide? how many on this forum and how many people with a fly away will show that on this forum?

What would you say are the key factors that would guarantee a confused and toilet bowl senario?
The only thing you can do is do good pre and after takeoff compass checks...  and find a good start point for a flight.
After that it is up to DJI SW.  ;-)

EDIT, in such cases (compass offset) the moment the SW needs to correct its position, than things go wrong. So not depending on height after takeoff.If you takeoffand fly up to 50 meters (no wind, no postion correction needed) no problem. Once you start to fly forward...no problem because the new GPS position is updated as well as the reference 'old' GPS position. Only when the new position differs from the ref position (i.e. due to wind), thus without RC input (fwd and / or roll) the fly away starts.


cheers

JJB

JJB* Posted at 3-5 10:11
uh Hallmark?  what is wrong with you?   one post you state that you do not think that Slup, others and I not trying to mislead people... GGood observation, well done!  
Speaking out for for myself; you are absolutely right!

Well, I am not against anyone, I just want to find the truth. Not even Hallmark.

I am still keen to experiment to nail this doubt I have about MI leading to broken contact, often no RTH, no subsequent control when contact maintained.

If you look at phone and computer forums, particularly where software is concerned, you will see the kit often crashes. Of course, overall, most phones and computers work perfectly. A glitch is more likely than the fact it is in an area of high interference. Like in a home or office. Because the kit doesn't rely on a compass, no one is offering that is a reason for them to fail.

Help me measure the effect of this MI on drones. It might help users avoid the problems they face. It won't hurt DJI, because they know what the answer is.
If I was a manufacturer, I wouldn't accept MI as a reason to replace a drone. I might internally acknowledge a software issue and still do the right thing with a replacement.

hallmark007 Posted at 3-5 10:23
I think you should go read my post again, I never said you were or had hit the self destruct button. But it might require you reading other posts.

I think it’s clear where the support lies here.

oke, but is was your reaction on my post.

JJB* Posted at 3-5 10:02
Hi Alan,

Yes, this log is not hard to understand, compass offset to the actual heading is the cause of correcting signals to the wrong motors.

Big question is :  why did this compass was offset ?  due to magn interference or due to ??
Or was the compass OKE and the yaw reference signal out of tune in the IMU?

Hi JJB:

Something we tend to overlook is possibility of a source of magnetic interference on (or with) the Pilot.  Few such examples: Ferrous metal - rings, watches, bracelets (popular magnetic bracellets for arthritis), or medical implants in hands or forearm.  Some SmartDevices with ferrous metal or generating magnetic field could be possible sources.  

When I did one compass / source magnetic field test; the CrystalSky Ultra with R.C. mounted below it would cause some compasses interference, when CrystalSky was closest to Mavic.


I know from testing, power-up is a critcal time when it comes to magnetic interference.  Placing Mavic Pro P near a marginal source and powering up, would result in Mavic Pro P not detecting a source of magnetic interference either at power-up point or when drone was moved to another similar source of magnetic interference.  


One of reasons long ago, I suggested checking (new / unknow) takeoff spots for magnetic interference with an Gauss/Tesla  meter App running on your SmartDevice.  


You could power drone up while holding it in air, moving drone to point of take off, and setting it down; then check drone's compass reads correctly.  However, powering drone up raised 2-meters off ground could bias barometer, resulting in false Zero altitude.  Possibility I have never checked to see if it would causes close to ground flight or landing issues.

JJB* Posted at 3-5 10:35
However, why does stick control fail?  stick control did not fail, in this kind of fly away it is possible to steer and get the craft in control ( but difficult as craft accelerates and is often relative far away to visual see which steering has the right effect )
But the OP did not do that, see the chart.
At ID 290 started to move, and just shortly left stick and yaw right was applied.

Thanks JJB

Wow it’s incredible how others put up wit this continuing trolling by this guy. He is even on this thread lying to the op and in yellow I clearly point to his blind lying.
Now it’s time for this guy who only came to this thread to troll me, to try destroy what was a normal but at sometimes heated debate, and he is fully responsible for this kind of ridiculous outburst on many threads, particularly if I’m on them.

People can clearly see where I ask to check compass, and believe the most important place to check it is on the ground, and I’m certain jjb would agree with this as he has in fairness to him complimented me many times for posting this preflight, as have hundreds more and 26,000 views.
Anyways highlighted below in yellow..

JJB* Posted at 3-5 10:38
oke, but is was your reaction on my post.

My reaction was simply because your post seemed to indicate that what I said was completely out of turn or in some way tainting what you might have thought occurred.

And your reaction caused another reaction by HT who seems to be looking for any angle to cause trouble on threads I participate on .