Took apart mavic
3884 25 2017-4-30
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thehippoz
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Took apart to shield wiring to the rears. It runs right by the gps noticed so shielded them all the way to the swivel. I'll check it out tomorrow and see how compass numbers look, but hoping that should pretty much end high compass values when in sport for over a minute. Think might replace the tim tomorrow just to do it.



It works great. It's double shielded into the swivel and wrapped with kapton tape.
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2017-4-30
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way wrong
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Interesting, I have thought that too. Let us know how it does work out?
2017-4-30
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Lok Mavic
lvl.3
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Will this void the warranty?
2017-5-1
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SkunkWerxs
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thehippoz,  I read either here or someplace else about the motor leads causing interference , I can't  
                 remember if it was with the Compass or GPS --- the solution to the persons issue was to
                 put a couple of twists to the motor leads where they were coming out of the arms to the
                 Circuit Board and it seamed to have solved his problem ---- You took it a step further which
                 is the correct and proper way to eliminate any Stray EMF and EMI interference that is being
                 created by wiring carrying current to or from the circuit board -- Your method is way better
                 then twisting wires leads, I hope it solves your problem ?

                                  Extra points to you for showing everyone the right way on how to eliminate EMF and EMI
                       within an electronic circuit --- Excellent Thinking !!!!
                 
                                                                              
FlySafe-Fly Free
               

                                 
                    
2017-5-1
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DroneFlying
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SkunkWerxs Posted at 2017-5-1 03:22
thehippoz,  I read either here or someplace else about the motor leads causing interference , I can't  
                 remember if it was with the Compass or GPS --- the solution to the persons issue was to
                 put a couple of twists to the motor leads where they were coming out of the arms to the

I read either here or someplace else about the motor leads causing interference , I can't remember if it was with the Compass or GPS --- the solution to the persons issue was to put a couple of twists to the motor leads

I'm guessing that this thread is where you read that.
2017-5-1
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SkunkWerxs
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DroneFlying Posted at 2017-5-1 03:44
I read either here or someplace else about the motor leads causing interference , I can't remember if it was with the Compass or GPS --- the solution to the persons issue was to put a couple of twists to the motor leads

I'm guessing that this thread is where you read that.

DroneFlying ,  Yes That's the thread --- Thanks

2017-5-1
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thehippoz
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SkunkWerxs Posted at 2017-5-1 03:22
thehippoz,  I read either here or someplace else about the motor leads causing interference , I can't  
                 remember if it was with the Compass or GPS --- the solution to the persons issue was to
                 put a couple of twists to the motor leads where they were coming out of the arms to the

Yeah, fly it today (I hope). If not tomorrow. It's the compass that goes high.

But I have family problems, crazy sister of mine at it again. So I'll get it done if I have time today. Have to talk to a lawyer, they are weasels in disguise themselves.
2017-5-1
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digitalintruder
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+1 interested in seeing the results - and hopefully if positive dji could incorp.
2017-5-1
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jamgabbi
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OH my I could never take mine Apart and get it back together

looks interesting  

thank you  
2017-5-1
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hootbird
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Can't tell from pic but a shield needs to be grounded on ONE end to be effective.
2017-5-1
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thehippoz
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Works great, stopped at the park earlier and got a fly in. I'll upload the video and edit the op. There's no effect on the compass now. None, nothing changes in sport. This is what dji needed to do from the start.

Didn't get a decent compass calibration in because was by myself, but the video will speak for itself. The shielding is double wrapped (foil) inside, no need for ground because it's not an antenna, it's power. @hootbird I do a lot of prototyping, fab my own boards and write the logic in c. I understand emf at high power unlike a lot of designers, because I've designed very tiny high powered bucks, which if not designed right can cause a lot of havoc when you try putting high amperage through.

Why when reading they were twisting the wire on mavicpilots forum, kind of made me shake my head. I know they meant well but thick twisted wire acts like an inductor. While it looked to reduce interference for whatever reason, it can't solve the problem like this does.
2017-5-1
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thehippoz
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jamgabbi Posted at 2017-5-1 15:07
OH my I could never take mine Apart and get it back together

looks interesting  

The front clip at the nose is overkill. It really doesn't want to pop out those clips! {:4_177:} Have to use plastic tools.
2017-5-1
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PushSky
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I can confirm that wire routing will cause interference with the GPS.  After a crash my left rear motor wires came out of the clip and ran closer to the GPS wiring.  I was having seemingly random GPS signal loss.  After rerouting the wires back into the clip and away from the GPS wiring the Mavic began flying stably again.  Big relief to have that issue addressed.  
2017-5-1
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alirz5
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Is this some sort of wrap around shielding around the wires or did you have de solder the wires and route them through this shield pipe?
2017-5-1
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thehippoz
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alirz5 Posted at 2017-5-1 19:12
Is this some sort of wrap around shielding around the wires or did you have de solder the wires and route them through this shield pipe?

Oh I use a soldering station. Around 380C to take off and 420C with new rosin core (I like to run hot). Left the wire the same length stock. This is the type of shielding used https://www.amazon.com/AmazonBas ... Feet/dp/B01DN7NM4M/

2017-5-2
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daivatam
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I think it is better to shield also the gps module with copper foil on the part to the inside of the drone...
2017-5-5
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Danny-B-
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First, what is the audio on the video ?? Jeez, i had to put it on mute lol

Second, i presume you could acheive the same result by just wrapping the wires in aluminium foil and taping it with kapton tape?
2017-5-5
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thehippoz
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Danny-B- Posted at 2017-5-5 16:09
First, what is the audio on the video ?? Jeez, i had to put it on mute lol

Second, i presume you could acheive the same result by just wrapping the wires in aluminium foil and taping it with kapton tape?

I would buy the amazon cl2 coax. It's double shielded with foil inside already. If worried about soldering, can probably get away with decent 60w iron, some 66/44 rosin core solder and a sal ammoniac block https://www.amazon.com/SRA-Sal-A ... ock/dp/B01I4QFZPG/. It's a small job to solder it back in.

Might as well get some cheap copper braid to clean up the old solder. I have a station because I solder so much, but the non adjustable would probably work.

And audio.. Lol yeah now that think about it bad choice. But it's up least. Oh flux too- gonna need it.
2017-5-5
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Danny-B-
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thehippoz Posted at 2017-5-5 16:28
I would buy the amazon cl2 coax. It's double shielded with foil inside already. If worried about soldering, can probably get away with decent 60w iron, some 66/44 rosin core solder and a sal ammoniac block https://www.amazon.com/SRA-Sal-A ... ock/dp/B01I4QFZPG/. It's a small job to solder it back in.

Might as well get some cheap copper braid to clean up the old solder. I have a station because I solder so much, but the non adjustable would probably work.

I'm fine with soldering, built many racing quads and fixed wings DIY, i just wondered if the same result could be acheived by simply wrapping the wires rather than full on encasing them. ... i guess if the tops off, you might aswell go the whole hog and do it properly though.

Cheers,
2017-5-5
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thehippoz
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Danny-B- Posted at 2017-5-5 16:36
I'm fine with soldering, built many racing quads and fixed wings DIY, i just wondered if the same result could be acheived by simply wrapping the wires rather than full on encasing them. ... i guess if the tops off, you might aswell go the whole hog and do it properly though.

Cheers,

Yeah true. Taking off the front clips takes a little effort. I managed to get it off without any scars using plastic tools, but can see that being the hard part. It doesn't want to come out.
2017-5-5
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SkunkWerxs
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Danny-B- Posted at 2017-5-5 16:36
I'm fine with soldering, built many racing quads and fixed wings DIY, i just wondered if the same result could be acheived by simply wrapping the wires rather than full on encasing them. ... i guess if the tops off, you might aswell go the whole hog and do it properly though.

Cheers,

Danny , Incasing them is the whole idea about Shielding , thehippoz actually killed two birds with one stone.
                                        He reduced or eliminated the EMF and EMI interference he was experiencing.
Magnetic fields can be re-routed around objects. This is a form of magnetic shielding. By surrounding an object with a material which can "conduct" magnetic flux better than the materials around it, the magnetic field will tend to flow along this material and avoid the objects . This allows the field lines to terminate on the opposite poles, but just gives them a different route to follow.
                                        Magnetic fields (forces are caused by magnetic fields) cannot be blocked, That is, there is no such thing as a magnetic insulator.
Hope this info help   
2017-5-5
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AG0N-Gary
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Actually, grounding the shield IS the correct thing to do.  And yes, the wires to the motors are actually antennas, radiating any noise on the wires to surrounding circuitry.  The radiation is minimized considerably by twisting them, as indicated in the other forum.  Even more can be achieved by fully shielding them.
2017-5-5
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thehippoz
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AG0N-Gary Posted at 2017-5-5 17:56
Actually, grounding the shield IS the correct thing to do.  And yes, the wires to the motors are actually antennas, radiating any noise on the wires to surrounding circuitry.  The radiation is minimized considerably by twisting them, as indicated in the other forum.  Even more can be achieved by fully shielding them.

No, but be my guest. End up with noise all over the system, and who knows what that would do. It's not like there's access to real earth up there. I'm not talking shet here I've built from eagle cad up. High powered DC circuits must be routed correctly or you end up with all kinds of problems. Like in my bucks, went through several designs before I was happy with the ripple, am able to keep the power clean and push crees way beyond spec. I remember one design where I twisted wiring to the led and the mosfet suffered and eventually went. That's how I found not to do that. I know most guys think, well they twist network wire so.. High power it's a whole different ball game, routing and noise become really important.
2017-5-5
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thehippoz
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fansca9280ea Posted at 2017-5-12 14:31
I'm not a good solderer.. so I'm not about to do any soldering.. but what's the best thing to wrap the wires with to improve the compass values?

This could work https://www.zippertubing.com/EMI ... apes-and-Wraps.html

Haven't used the stuff, but it maybe the way to go. gl
2017-5-12
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