DIY rear compass cabling fix

[Randy]

Unless I've missed it there are no incidents or data to suggest that the rear compass noise caused by high currents in the rear motor wires is related to the gpsHealth-drops-from-1-to-1 issue. That's not to say there isn't a relationship, just saying that, so far, there has been no data to suggest they are related. That's why I'm interested to know if you have data to suggest they are related. In particular, do you have the .txt logs from flights before twisting the wires that had a gpsHealth-drops-from-1-to-1 incident?

Yes I do, but from reading here it sounds like it's complicated to get them off the card then upload them, you have to use ITunes, or DJI assistant or something like that. Sounds like my GPS problem may not be solved after all.

 

[BudWalker]

Yes I do, but from reading here it sounds like it's complicated to get them off the card then upload them, you have to use ITunes, or DJI assistant or something like that. Sounds like my GPS problem may not be solved after all.

But, how would you know if it were a gpsHealth-drops-from-5-to1 issue unless you've seen the log? It's not that hard to retrieve the .txt log file which resides on the tablet. Here is a YouTube that explains how.

 

[Randy]

But, how would you know if it were a gpsHealth-drops-from-5-to1 issue unless you've seen the log? It's not that hard to retrieve the .txt log file which resides on the tablet. Here is a YouTube that explains how.

I'll give it a try

 

[Randy]

But, how would you know if it were a gpsHealth-drops-from-5-to1 issue unless you've seen the log? It's not that hard to retrieve the .txt log file which resides on the tablet. Here is a YouTube that explains how.

I managed to get the .txt files, where should I upload them?

 

[BudWalker]

I managed to get the .txt files, where should I upload them?

Since they are .txt files they can be attached to a post here. No need to zip them, just hit the Upload a File button.

 

[Randy]

Since they are .txt files they can be attached to a post here. No need to zip them, just hit the Upload a File button.

the 2/28/2017 flight is pre wire twists, the next 4 are after.

 

[RallySoob]

Ahha so i was right about later build Mavics being updated as far as bug fixes ... like how newer ones controller battery last much longer etc .

This is first i seen sum1 tackle this issue tho gl bro

 

[CaveDrone]

Are you referring to only twisting wires inside the arm itself?

Btw, I put this image together to help show what's going on.

View attachment 7151

Sweet! Xray! You got access nice stuff!

 

[Randy]

Sweet! Xray! You got access nice stuff!

Must be a dentist!

 

[BudWalker]

the 2/28/2017 flight is pre wire twists, the next 4 are after.

The 2/28/2017 flight doesn't have a switch to ATTI, just a switch to ForceLanding at the very end. gpsHealth remained at 5 throughout the entire flight.

 

[Randy]

The 2/28/2017 flight doesn't have a switch to ATTI, just a switch to ForceLanding at the very end. gpsHealth remained at 5 throughout the entire flight.
View attachment 8104

This is the flight where it started drifting, and I am positive that it switched to ATTI mode, I had to put it in sport mode to overcome the drift, just moving the controls in ATTI wouldn't do it. GPS signal was weak all the way to touch down. Here is a screenshot from flight records for the very flight that you can play back in the GO 4 app for the 2/28/2017 that shows "ATTI" in the upper left hand corner, so I don't know what's going on here.

 

[BudWalker]

This is the flight where it started drifting, and I am positive that it switched to ATTI mode, I had to put it in sport mode to overcome the drift, just moving the controls in ATTI wouldn't do it. GPS signal was weak all the way to touch down. Here is a screenshot from flight records for the very flight that you can play back in the GO 4 app for the 2/28/2017 that shows "ATTI" in the upper left hand corner, so I don't know what's going on here.

Here is the flight DJIFlightRecord_2017-02-28_[07-26-16].txt

It occurred at 16:26:16 and it never entered Sport mode. Total distance was 60 meers.

 

[Randy]

This is the flight where it started drifting, and I am positive that it switched to ATTI mode, I had to put it in sport mode to overcome the drift, just moving the controls in ATTI wouldn't do it. GPS signal was weak all the way to touch down. Here is a screenshot from flight records for the very flight that you can play back in the GO 4 app for the 2/28/2017 that shows "ATTI" in the upper left hand corner, so I don't know what's going on here.

playing it back it started takeoff, ATTI, GPS, ATTI,SPORT, GPS, SPORT,ATTI,SPORT,OPTI,SPORT, OPTI, TRIPOD. Can I send you this file so you can see?

 

[Randy]

Here is the flight DJIFlightRecord_2017-02-28_[07-26-16].txt
View attachment 8115
It occurred at 16:26:16 and it never entered Sport mode. Total distance was 60 meers.

I'm sorry, I think I sent you the wrong one for that day, here is the right one

 

[BudWalker]

I'm sorry, I think I sent you the wrong one for that day, here is the right one

Yes, that would be the flight and it certainly looks like the cause could have been Sport mode full elevator. We need to have @ScrappyMavic take a look at this. Would it be possible to get the .DAT file for this flight? To see how to retrieve the .DAT look here. It will be too large to attach to a post so you'll need to Dropbox it and provide the link.

 

[Randy]

Yes, that would be the flight and it certainly looks like the cause could have been Sport mode full elevator. We need to have @ScrappyMavic take a look at this. Would it be possible to get the .DAT file for this flight? To see how to retrieve the .DAT look here. It will be too large to attach to a post so you'll need to Dropbox it and provide the link.

I'll try it tomorrow, looks like I need to plug the MP into the computer

 

[Mr Spock]

Ahha so i was right about later build Mavics being updated as far as bug fixes ... like how newer ones controller battery last much longer etc .

This is first i seen sum1 tackle this issue tho gl bro

The RC battery lasts longer in newer Mavics????

 

[ScrappyMavic]

Yes, that would be the flight and it certainly looks like the cause could have been Sport mode full elevator. We need to have @ScrappyMavic take a look at this. Would it be possible to get the .DAT file for this flight? To see how to retrieve the .DAT look here. It will be too large to attach to a post so you'll need to Dropbox it and provide the link.

Based on the data in @Randy 's TXT file, I'd say the second unwanted ATTI event was quite clearly magYaw / Yaw deviation issue leading to TBE. There are roll oscillations present without any stick inputs right before the ATTI event, along with TBE signature in GeoPlayer. Without the magYaw data from the .DAT file it's hard to diagnose the other ATTI events in the file, but most likely they are caused by the same problem.

The posts recommending frequent compass calibrations are probably overzealous. However I think there is something to be said for getting "one good" compass calibration. I experienced fairly frequent ATTI and TBE events from magYaw deviation. After doing one good compass calibration outside in the open air, far from any metal and without my phone/watch, etc, I've not had any more ATTI events. I think Mavics have some weakness for this magYaw issue, but a good compass calibration does seem to help prevent issues.

Clear TBE oscillations without stick input prior to second ATTI event

 

[Randy]

Based on the data in @Randy 's TXT file, I'd say the second unwanted ATTI event was quite clearly magYaw / Yaw deviation issue leading to TBE. There are roll oscillations present without any stick inputs right before the ATTI event, along with TBE signature in GeoPlayer. Without the magYaw data from the .DAT file it's hard to diagnose the other ATTI events in the file, but most likely they are caused by the same problem.

The posts recommending frequent compass calibrations are probably overzealous. However I think there is something to be said for getting "one good" compass calibration. I experienced fairly frequent ATTI and TBE events from magYaw deviation. After doing one good compass calibration outside in the open air, far from any metal and without my phone/watch, etc, I've not had any more ATTI events. I think Mavics have some weakness for this magYaw issue, but a good compass calibration does seem to help prevent issues.

Clear TBE oscillations without stick input prior to second ATTI event
View attachment 8240

View attachment 8241

So what does this mean? Is it possible that twisting my wires may have taken care of this? Has anybody looked at the post twist files to compare? I have 2 metal roofs here, it was never a problem with the phantom 4, but maybe the Mavic is more susceptible to this, I don't know.

 

[BudWalker]

So what does this mean? Is it possible that twisting my wires may have taken care of this? Has anybody looked at the post twist files to compare? I have 2 metal roofs here, it was never a problem with the phantom 4, but maybe the Mavic is more susceptible to this, I don't know.

I was waiting for the .DAT from the flight where you had the incident. The .txt does not have enough info. If you want to see if your problem has been fixed then we'll also need the .DAT for a flight after the fix with Sport mode, full elevator, and the same heading as the first incident (about 38 degrees)