amferreira Posted at 4-29 08:48
First this error only comes after the FW update because it wasn't on the previous FW. This new FW added this error in oder to prevent uncommanded descents that were happening. These descents were occuring due to lost lift of rear propeller. This lost lift can derive from defective shape of the propeller, lower voltage sent from the battery or flight conditions like wind. One or a combination of these factors on FW .0400 would give a Max power warning that many MM pilots ignored.

I started having the Max power warnings when I updated to FW .0400 and when reverting to FW .0300 the warnings disappeard. I looked at a solution and while doing indoor flights to see what was happening I realized that I was getting more warnings with one of the batteries. So I though I may had a problem with the firmware of that battery and refreshed the FW of the drone, batteries (one at a time) and controller using the DJI Assistant 2. After that I had more than 3 hours flying without any warning. On one of my latest flights I noticed that the Max power warning come up only once when I got also a Strong wind warning and battery was lower than 40%.

If you got intermittent max power warnings before, I would be surprised if you will not get this new Motor Error warning, on your first flight after the FW upgrade.

Zbip57 Posted at 4-29 07:49
If the firmware update completes successfully via the app, what makes people think repeating the update via the Assistant software should make any difference?  Either it's updated or it's not.

Downgrading to the previous firmware version does not "cure" the issue.  The fact that the new firmware version displays this motor speed error, and previous versions did not, only means that earlier firmware versions did not include this test or its warning.

If the firmware update completes successfully via the app, what makes people think repeating the update via the Assistant software should make any difference?  Either it's updated or it's not.

You would think so, but in reality the update can be reported as as successful, when some little component of the firmware did not get upgraded or ended up corrupted. That's exactly why DJI Assistant gives you a "Refresh" option. It's not just DJI, GoPro had similar issues where they were recommending a manual update (copy the firmware on the SD card instead of using the app).

DaMa Posted at 4-29 00:03
Did a little test. Propellers paired with different play (1 mm with 4 mm, back left). On ground, one propeller can be raised 3 mm higher until it stops in play.
The result of the hover inside is astounding, both propellers run on one level. The contact pressure caused by the centrifugal forces can play a role here, I can't say how the whole thing looks at S outside (rain). S-mode inside no error message.

What exactly did you do? Did you raise the props where they attach to the motor? I don't understand what "1mm with 4mm, back left" means. Thanks.

bmg2 Posted at 4-29 09:37
What version are you using? I've got the same issue with Dji Assistant 2 for Mavic versions 2.0.10 and 2.0.12.

Dji assistant is very troublesome it has often been recommended to delete app and reinstall.

Deucalion Posted at 4-29 08:02
"The question remains, what causes this need to replace prop blades?  The original blades have been on my Mini since I bought it December.  The spare blades that came in the Combo Pack are the same vintage and haven't been out of their box until today."

No one really knows why the (good and bad) props are different, only that they are certainly different. You can look at the RPM with the bad props and see that they are significantly higher than with the good props. You can use DatCon to get the RPM data from your DAT file. I plan on digging deeper into this myself, when I have time.

Simple equation,

Bad props = more RPM on the rotors

New props = Less RPM

Conclusion = New props have more Pitch. Even 1 mm can make diff.

hallmark007 Posted at 4-29 09:32
Uncommanded descents have been happening since day one, it was nothing to do with .400 FW, you say these uncommanded was as a result of rear props failing to lift craft  “where are you getting this information from” and are you now saying all rear props have problems and if this is the case what of extra props that came with craft, are these better props than we have on the rear motors of the mini or should we dump them.
And if the rear props were faulty how do you explain all users being able to fly around for most of there flight but then out of left field craft starts to descend as well as going backwards .

It seems that you didn't understand what I have said. Firmware .0400 didn't make the start uncommanded descends. What I have said is that FW .0400 made the error Max power appear to make pilots aware of the existance of a problem.

When I downgraded the FW to .0300 the errors disappeared but that doesn't mean that anything was changed. Just the error message didn't appeared. The FW .0400 made changes, maybe one was a higher sensitivity for the power of motors situation.

Because this warning wasn't enough IMO DJI now on FW .0500 added this new motor warning in order to try to avoid uncommanded descents.

What I have said was based on my experience doing flights indoor and outdoor with the FW .0300 and .0400. From that experience a noted the following:

Indoor and outdoor flights with FW .0300 show no errors with all tree batteries.

Indoor and outdoor flights with .0400 showed several Max power errors with all three batteries, mostly with battery nº2.

Downgrade to FW .0300 no errors.

Upgrade to FW .0400 with DJI Assistant. No errors during 3 hours of flights outdoor. On two of the last flights I had a Max power error when there was wind and battery below 40%. Again battery nº 2 had more errors. I did some flights after without errors.

Upgraded to FW .0500 with the DJI Assistant. Due to the lockdown and rain I can't go test outdoor. Today and before I wrote this post I tested indoor hovering and moving around with prop guards. I didn't got the Motor error that is being discussed but I got max power warning as follows:

Battery 2 - warning come up at 70% battery and repeated 2700 times until landing.
Battery 1 - warning come up at 50% battery and repeated 1679 times until landing.
Battery 3 - warning come up at 40% battery and repeated 259 times until landing.

The error come coupled with Extra payload warning due to the prop guards.

From all observations and tests (I still have to conduct outdoor tests) I can infer that my battery 2 has some kind of problem that can be related with the firmware and how the battery supplies energy to the drone.

As far as propellers is concerned, I have seen pilots that solved their uncommaded descents by replacing rear props. One of them remarked that the numbers of the new props are different from the ones installed from factory. This can indicate a possible mismatch from factory that could have an adverse impact on the lift.

HedgeTrimmer Posted at 4-29 07:42
Coriolis Effect - It's the left one North of equator, right one South of equator.

(Just kidding)

Nah, I think it's the compass calibration...

120ccpm Posted at 4-29 10:15
What exactly did you do? Did you raise the props where they attach to the motor? I don't understand what "1mm with 4mm, back left" means. Thanks.

My propellers front/rear/left/right are differently (screw/propeller play) in attachment. I have mixed one blade with much play with a blade with very little play. If you now carefully lift the tips of the blades to the "end of the play", one blade can be rised 4 mm and the opposite 1 mm. The assumption that this would lead to an uneven run and thus to the provoked mistake has not been confirmed. Both blades runs evenly in flight, despite the different play. But I did it only inside, not outside with full speed.

amferreira Posted at 4-29 11:50
It seems that you didn't understand what I have said. Firmware .0400 didn't make the start uncommanded descends. What I have said is that FW .0400 made the error Max power appear to make pilots aware of the existance of a problem.

When I downgraded the FW to .0300 the errors disappeared but that doesn't mean that anything was changed. Just the error message didn't appeared. The FW .0400 made changes, maybe one was a higher sensitivity for the power of motors situation.

Thanks, I didn't realize that 0.300 didn't give the max power msgs. That explains why this issue was even more perplexing in the beginning (back when the drone was released). Fortunately, I missed that period.

It does seem to reason that your props may need replacing, but please let us know what your find when you are able to fly again.

DaMa Posted at 4-29 12:22
My propellers front/rear/left/right are differently (screw/propeller play) in attachment. I have mixed one blade with much play with a blade with very little play. If you now carefully lift the tips of the blades to the "end of the play", one blade can be rised 4 mm and the opposite 1 mm. The assumption that this would lead to an uneven run and thus to the provoked mistake has not been confirmed. Both blades runs evenly in flight, despite the different play. But I did it only inside, not outside with full speed.

Thanks, this rules out screws. I will add it to the list.

Cases
Rubber Bands
Foam
Paint
Screws

hallmark007 Posted at 4-29 10:26
Dji assistant is very troublesome it has often been recommended to delete app and reinstall.

I've actually done that, and on 2 different computers...no luck. I think my regular update through the fly app is ok, but it would be nice to have the DJI Assistant 2 running also, for a backup if needed.

Deucalion Posted at 4-29 12:26
Thanks, I didn't realize that 0.300 didn't give the max power msgs. That explains why this issue was even more perplexing in the beginning (back when the drone was released). Fortunately, I missed that period.

It does seem to reason that your props may need replacing, but please let us know what your find when you are able to fly again.

The error message come up at the begining in sport mode, but that was before I got my Mini. With FW .0300 I didn't got any error message but that doesn't mean that there wasn't a problem. Just that the FW didn't popped out the error message. That's why I said the sensitivity of the warning was changed from FW .0300 to FW .0400 and was done to try to make pilots aware that there was a problem with the motors that were reaching max power. That didn't stop uncommanded descents and the FW .0500 brought this new motor error message.

amferreira Posted at 4-29 12:52
The error message come up at the begining in sport mode, but that was before I got my Mini. With FW .0300 I didn't got any error message but that doesn't mean that there wasn't a problem. Just that the FW didn't popped out the error message. That's why I said the sensitivity of the warning was changed from FW .0300 to FW .0400 and was done to try to make pilots aware that there was a problem with the motors that were reaching max power. That didn't stop uncommanded descents and the FW .0500 brought this new motor error message.

I am hoping that 500 doesn't do an uncommanded descent at all. I realize that it has to slow down the props in order to be able to balance, but grounding the AC mid flight was overkill. The users who experienced it, could still start back up and fly, as long as the drone didn't descend into water, or a tree, or a pit bull kennel.

Deucalion Posted at 4-29 12:27
Thanks, this rules out screws. I will add it to the list.

Cases

If I'm not mistaken, dji recommends changing the propellers in pairs. That was the background to the experiment. I didn't suspect the screws, but the holes in the propellers.

djiuser_nbGIzHIzjp03 Posted at 4-29 09:04
I have same issue since the update ..
Replace props and still beeping with the error and it's the back left arm

Rather than keep messing with it.  Open a ticket with DJI for return and repair / replace.

With enough returns, perhaps DJI will figure out what cause is, and resolve problem.   Whether it be, FW, FW updater, bad batch of props, aft port motor / arm, etc.

Deucalion Posted at 4-29 12:58
I am hoping that 500 doesn't do an uncommanded descent at all. I realize that it has to slow down the props in order to be able to balance, but grounding the AC mid flight was overkill. The users who experienced it, could still start back up and fly, as long as the drone didn't descend into water, or a tree, or a pit bull kennel.

The FW doesn't do the uncommanded descent, that happens when propellers do not generate enough lift. When the ESC verifies that a motor reaches max speed the error is displayed. This is done to make pilots stop and look at the propellers.

Like I stated before lift is dependent of propeller shape, battery power supply and operational environment like wind. All three causes can generate a lower lift and IMO DJI believes that propeller shape is the most likely cause.

Deucalion Posted at 4-29 12:26
Thanks, I didn't realize that 0.300 didn't give the max power msgs. That explains why this issue was even more perplexing in the beginning (back when the drone was released). Fortunately, I missed that period.

It does seem to reason that your props may need replacing, but please let us know what your find when you are able to fly again.

One guy says he didn't get it on 1.03 and now you're saying "I didn't realize that 0.300 didn't give the max power msgs"... Look back on this forum after 1.03, what will you find? Max power/not enough force errors, I have my own logs to show that. Just because one member claims to not see the message doesn't mean it didn't exist for others on that same fw.

I myself even brought this up pages ago, 1.02 clean logs, 1.03 dirty logs, 1.04 logs are clean again. It's not the same for everyone.

120ccpm Posted at 4-29 10:05
If the firmware update completes successfully via the app, what makes people think repeating the update via the Assistant software should make any difference?  Either it's updated or it's not.

You would think so, but in reality the update can be reported as as successful, when some little component of the firmware did not get upgraded or ended up corrupted. That's exactly why DJI Assistant gives you a "Refresh" option. It's not just DJI, GoPro had similar issues where they were recommending a manual update (copy the firmware on the SD card instead of using the app).

Long running problem with DJI's updater via GO apps or Assistant.

How any company could put out updater that fails to verify the update was applied correctly is a crock.
Especially a company valued in Billions.

SLiWooDy Posted at 4-29 09:47
This guy has the problem solved;

https://youtu.be/edTWQcMJ-3M

Yeah I said it was probably caused by drone storage from the start early on in this thread. Even the guy from DJI said the same thing. That left side prop is the one the weight of the drone sits on in the case or whatever you store your drone in. If you don't sit it right with the props tucked in the pressure will be on the props in the case. I don't really use my fly more case. I don't like walking around with a tiny briefcase it just looks silly. I have a camera backpack with a hidden back access for my drone so I can walk around anywhere without anyone knowing any different. The drone itself sits in a sunnylife hard case which has moulds for the props so there is no pressure on them at all and you can easily sit it in it without any prop issues due to the case moulds. I used to use these hard plastic prop holders which hold the props exactly as they came when you buy the drone but I wanted more protection and less fuss while I was out flying so got the tiny case.





The thing I find interesting though is that people have brand new drones with the issue. So unless the prop has warped in the case somehow it's all very strange. I have never had any issues with this. I only update from my phone too without issue on an iphone xs.

bmg2 Posted at 4-29 12:38
I've actually done that, and on 2 different computers...no luck. I think my regular update through the fly app is ok, but it would be nice to have the DJI Assistant 2 running also, for a backup if needed.

Speaking from experience -  Don't expect any help from DJI with getting Assistant-2 working properly.

Deleting and reinstalling Assistant-2 may get it working on Windows machine.
Usually, you have to disable security for PC in BIOS.   Install Assistant-2, insure it is working.  Then re-enable PC's security in BIOS.   Do believe a forum member here came up with a way  in Windows to do same.

amferreira Posted at 4-29 13:31
The FW doesn't do the uncommanded descent, that happens when propellers do not generate enough lift. When the ESC verifies that a motor reaches max speed the error is displayed. This is done to make pilots stop and look at the propellers.

Like I stated before lift is dependent of propeller shape, battery power supply and operational environment like wind. All three causes can generate a lower lift and IMO DJI believes that propeller shape is the most likely cause.

The drones flew again immediately after the event of an uncommanded descent to the ground. That is why we know that the FW performed the descent. That is also why we say "uncammanded descent" and not "fall". If the props were at max and the drone still fell, then there is no way you could fly it again. What happens is that FW freaks out after enough of the max power messages register, or when they register under just the right conditions, and changes into a descent mode, throttling back the props and not allowing you to override. Once it lands and is reset, you can fly again, until the situation arises again.

ABeardedItalian Posted at 4-29 13:32
One guy says he didn't get it on 1.03 and now you're saying "I didn't realize that 0.300 didn't give the max power msgs"... Look back on this forum after 1.03, what will you find? Max power/not enough force errors, I have my own logs to show that. Just because one member claims to not see the message doesn't mean it didn't exist for others on that same fw.

I myself even brought this up pages ago, 1.02 clean logs, 1.03 dirty logs, 1.04 logs are clean again. It's not the same for everyone.

Ok, I believe you. You do know more of the history about this than me by far.

amferreira Posted at 4-29 13:31
The FW doesn't do the uncommanded descent, that happens when propellers do not generate enough lift. When the ESC verifies that a motor reaches max speed the error is displayed. This is done to make pilots stop and look at the propellers.

Like I stated before lift is dependent of propeller shape, battery power supply and operational environment like wind. All three causes can generate a lower lift and IMO DJI believes that propeller shape is the most likely cause.

"Like I stated before lift is dependent of propeller shape, battery power  supply and operational environment like wind. All three causes can  generate a lower lift and IMO DJI believes that propeller shape is the  most likely cause."

From another thread (About mini uncontrolled descent!!! DJI what do you think??), talking about Mavic Mini's uncontrolled (or uncomanded) descent.


Deformed blades, suddenly (highly unlikely)   Added: initial slight deformation, which is worsened during flight sufficently to cause problems?

Spoiler Alert, no response from DJI...

Deucalion Posted at 4-29 14:01
The drones flew again immediately after the event of an uncommanded descent to the ground. That is why we know that the FW performed the descent. That is also why we say "uncammanded descent" and not "fall". If the props were at max and the drone still fell, then there is no way you could fly it again. What happens is that FW freaks out after enough of the max power messages register, or when they register under just the right conditions, and changes into a descent mode, throttling back the props and not allowing you to override. Once it lands and is reset, you can fly again, until the situation arises again.

Great unless your drone is over water or over edge cliff, when FW freaks and throttles back.   

HedgeTrimmer Posted at 4-29 14:17
Great unless your drone is over water or over edge cliff, when FW freaks and throttles back.

All Deucalion is saying is that just because the props failed at that time doesn't mean it's not fw related.

As we've seen pages back, you can cut and deform the mini's props and the drone will still fly. This is what hallmark keeps going back too. If you take off, hover, and fly for 10 minutes before the un-commanded decent it's not the props that caused the descent. Okay it might actually be, but whats trying to be said is the props don't suddenly fail and the drone falls out of the sky. The props are fine and still provide lift and can be flown on again, if the props when failed were so bad to not sustain lift you couldn't fly again with those bad prop.

So looping back it's the chicken or the egg, does the bad props invoke issues with the mini causing the un-commanded descent or is it the firmware faulty in another manner?

DJI were waiting....

ABeardedItalian Posted at 4-29 14:31
All Deucalion is saying is that just because the props failed at that time doesn't mean it's not fw related.

As we've seen pages back, you can cut and deform the mini's props and the drone will still fly. This is what hallmark keeps going back too. If you take off, hover, and fly for 10 minutes before the un-commanded decent it's not the props that caused the descent. Okay it might actually be, but whats trying to be said is the props don't suddenly fail and the drone falls out of the sky. The props are fine and still provide lift and can be flown on again, if the props when failed were so bad to not sustain lift you couldn't fly again with those bad prop.

Well, people have been posting graphs of the RPM and they are pretty high with the "suspect" props, and go back to normal with new props.

ABeardedItalian Posted at 4-29 14:31
All Deucalion is saying is that just because the props failed at that time doesn't mean it's not fw related.

As we've seen pages back, you can cut and deform the mini's props and the drone will still fly. This is what hallmark keeps going back too. If you take off, hover, and fly for 10 minutes before the un-commanded decent it's not the props that caused the descent. Okay it might actually be, but whats trying to be said is the props don't suddenly fail and the drone falls out of the sky. The props are fine and still provide lift and can be flown on again, if the props when failed were so bad to not sustain lift you couldn't fly again with those bad prop.

The warning is most likely there to point out prop has been put on incorrectly, but it’s likely the warning itself is not warning correctly.
I believe the main cause for sudden drops in altitude have been sorted by optimisation’s, so we are not seeing drops but warnings that all of a sudden allow you to fly home, as the warning reads Land or Return, if there was imminent danger of craft loosing altitude then the warning would read land immediately, just like the strong wind warning does, that warning tells you to land not go home and land.
To many ideas contradicting each idea, when people start talking about the need to X-ray props you know the arguments have reached and gone beyond the ridiculous.

deathsquad Posted at 4-29 13:54
Yeah I said it was probably caused by drone storage from the start early on in this thread. Even the guy from DJI said the same thing. That left side prop is the one the weight of the drone sits on in the case or whatever you store your drone in. If you don't sit it right with the props tucked in the pressure will be on the props in the case. I don't really use my fly more case. I don't like walking around with a tiny briefcase it just looks silly. I have a camera backpack with a hidden back access for my drone so I can walk around anywhere without anyone knowing any different. The drone itself sits in a sunnylife hard case which has moulds for the props so there is no pressure on them at all and you can easily sit it in it without any prop issues due to the case moulds. I used to use these hard plastic prop holders which hold the props exactly as they came when you buy the drone but I wanted more protection and less fuss while I was out flying so got the tiny case.

[view_image]

I like the look of that carry case.  It makes a lot more sense to stow the props oriented fore/aft like that, rather than tucked under the Mini's body.  

My Mavic Mini combo shipped with the Mini stowed with props installed in the carrying case.  I suppose if it had been stored for a long time like that, maybe even "brand new" the props might already have been deformed.

I replaced the props on my left rear motor today and test flew it just now.  It's quite windy out, but no motor speed error reported now.

I ordered the sunnylife case that holds the Mini and controller together from Ali Express.  But it won't hold the battery charger and spare parts.  https://www.aliexpress.com/item/4000371062421.html

Mind if I ask the source for your camera bag?

DaMa Posted at 4-29 12:22
My propellers front/rear/left/right are differently (screw/propeller play) in attachment. I have mixed one blade with much play with a blade with very little play. If you now carefully lift the tips of the blades to the "end of the play", one blade can be rised 4 mm and the opposite 1 mm. The assumption that this would lead to an uneven run and thus to the provoked mistake has not been confirmed. Both blades runs evenly in flight, despite the different play. But I did it only inside, not outside with full speed.

I see, thanks for clarifying. It would be equally interesting to see if those that are a bit loose, can be also rotated in a way to reduce pitch. I believe you know very well that even a couple degrees can make a difference...

Deucalion Posted at 4-29 12:27
Thanks, this rules out screws. I will add it to the list.

Cases

I think you ruled out "cases" a bit prematurely, but it's your personal list so I won't object...

hallmark007 Posted at 4-29 14:55
The warning is most likely there to point out prop has been put on incorrectly, but it’s likely the warning itself is not warning correctly.
I believe the main cause for sudden drops in altitude have been sorted by optimisation’s, so we are not seeing drops but warnings that all of a sudden allow you to fly home, as the warning reads Land or Return, if there was imminent danger of craft loosing altitude then the warning would read land immediately, just like the strong wind warning does, that warning tells you to land not go home and land.
To many ideas contradicting each idea, when people start talking about the need to X-ray props you know the arguments have reached and gone beyond the ridiculous.

"has been put on incorrectly".
Please articulate... what does that mean? CW vs CCW? Different mold markings? Screw not tight?

120ccpm Posted at 4-29 15:17
I think you ruled out "cases" a bit prematurely, but it's your personal list so I won't object...

Prematurely? I waited till hundreds of users were using cases without issues. Should I have waited for thousands of users? How many users using cases without issues does it take to rule out cases? And you know what is the funniest thing. Not one user ever demonstrated putting a drone with good props into a case and then pulling out a drone with bad props. Not one user even remembers putting it in their case different then the rest of us and messing up their props. This essentially was the case reasoning...

1. My props are bad.
2. Must be the cases.
Q.E.D.

120ccpm Posted at 4-29 15:19
"has been put on incorrectly".
Please articulate... what does that mean? CW vs CCW? Different mold markings? Screw not tight?

I think you’re well aware what I’ve said and what I mean, you seem to spend your time aimlessly defending what you’re saying, I think they’re so many variables regarding props loose props bad props damaged props props that fail the X-ray test props that need hauling through the ultrasonic , props put on new getting warning, props taken off one motor and put on a new motor, you’re so convinced this is only a prop problem that you have totally blinkered yourself.

Explain why dji would not insist in landing immediately on their warning, after all the big problem was drone couldn’t get home, but warning gives option to go home. So don’t ignore the fact that dji May well have optimized engines to try stop craft from descending.

I think it was Labroids brought to many users attention the need to correctly fit props and many didn’t realize and for new flyers I can understand this, with all other dji drones putting on props is failsafe, also because they came fitted it says that this could well have been in their thinking and further leaving warnings in packs which is a lottery to know who reads them. So incorrect props fitted badly fitted props yes I can believe this.
But not new props that haven’t been used needing to have an X-ray because they show no damage.

You know I did a flight course for commercial almost 5 years ago we were shown what to look for with damaged props when to check them change them etc, but never once were we told to put them through an ultrasonic or X-ray them, when the conversation gets around to Trumpian style arguments I get convinced that any sign of realism or even pragmatism goes out the window.

I wouldn’t advise anyone to remove and get rid of brand new props because of this warning, yes until it’s sorted and you need to get rid of the warning change it, but unless it shows some damage I wouldn’t tell anyone under X-ray the prop is no good.

I don’t have any plausible answer as to why craft with so called bad props took off fine flew for 20 minutes but then decided to land, I have yet to see a craft try to take off and fail because of bad props, surely we would have seen this at least once. And finally so far touch wood I haven’t seen one case of craft descending involuntary since FW update.

I also have seen jjb post in his own thread that his craft descended and looking at his own logs he seemed convinced bad props were not the cause of it, so that’s what I think, you can continue to flog the dead horse but I don’t think you have made much of a case to say this was completely down to bad props.

120ccpm Posted at 4-29 15:17
I think you ruled out "cases" a bit prematurely, but it's your personal list so I won't object...

I agree. There is also no one cause for all cases as he seems to think. I'm sure a lot of things can lead to the same outcome. All those things he mentioned can cause prop issues.

At the end of the day, if you get the warning about changing props and you do it, the warning goes away and the drone is fine. They don't want people with bad props losing their drone so they added the warning with the latest fw. End of story. How the props faulted can be any number of things but if you don't put any stress on the props in storage I think is the best advice I can offer.

ABeardedItalian Posted at 4-29 14:31
All Deucalion is saying is that just because the props failed at that time doesn't mean it's not fw related.

As we've seen pages back, you can cut and deform the mini's props and the drone will still fly. This is what hallmark keeps going back too. If you take off, hover, and fly for 10 minutes before the un-commanded decent it's not the props that caused the descent. Okay it might actually be, but whats trying to be said is the props don't suddenly fail and the drone falls out of the sky. The props are fine and still provide lift and can be flown on again, if the props when failed were so bad to not sustain lift you couldn't fly again with those bad prop.

You can cut or bend a prop (up to a certain point) and the MM will still take off and fly, but if you keep flying you're likely going to get errors. And if insist on flying, I'd say you're likely to experience an uncommanded descent. Speaking of those, it could really be 2 things:
1. some sort of "limp mode", where the FW reacts (over-reacts) to an error condition (like RPMs maxed out on one motor)
2. a true hardware issue, like an ESC overheating and going into thermal protection, and the flight controller being forced to throttle down the other motors too.

Regardless, my guess is that these descents are in response to a condition that "builds-up", and that's why you can fly the same MM later on, and everything works. I'm also of the opinion that props are the root cause of the above mentioned condition, and that these Motor Error warning have been introduced specifically to detect them in advance, before they cause bigger problems.
To those who say it's a bug, I respond: ignore the error and keep flying. You might get lucky and nothing happens, or you might end up with an uncommanded descend. No evidence (yet) of this, up to them to decide if they're willing to take the risk, to save a few $$ or to prove a point.

I really have nothing more to add on this topic...

hallmark007 Posted at 4-29 16:00
I think you’re well aware what I’ve said and what I mean, you seem to spend your time aimlessly defending what you’re saying, I think they’re so many variables regarding props loose props bad props damaged props props that fail the X-ray test props that need hauling through the ultrasonic , props put on new getting warning, props taken off one motor and put on a new motor, you’re so convinced this is only a prop problem that you have totally blinkered yourself.

Explain why dji would not insist in landing immediately on their warning, after all the big problem was drone couldn’t get home, but warning gives option to go home. So don’t ignore the fact that dji May well have optimized engines to try stop craft from descending.

I still don't understand the incorrectly installed prop idea but it's just as valid as anyone else's at this point. I don't know if you mean ccw prop on a cw motor or a prop put on upside down. I haven't seen everyone's mini's but all of the ones in videos/pictures people have shares there props look to be installed correctly.  I can think of One post where a user was having an issue taking off and the drone would immediately fly backwards, that is the only case I can see props being installed incorrectly and I don't even  know if that was his issue. It just comes to mind when I think of what incorrectly installed props would look like/cause and effect.

I haven't seen anyone say for sure that there's an issue with props, the most we have to go by is rpm data showing a loss of pitch. I'm working on a tutorial that shows how to check your .Dat for this information. My mini sure enough is showing higher rpm for both my rear motors, but my rear left is worse then it's rear right partner. I don't store my drone in the case, nor do I have a fancy stand. It stays folded on my desk, in a box, in a drawer or wherever I happened to of placed it. Now I'm more conscious of the prop orientation but it was nothing I took note of before. My props are still 1500rpm shy of being error triggering, but at least I have access to the information to check. What does this really mean? I couldn't tell you.

Like you've said this is beating a dead horse, all we know is prop deformation is happening, it's effecting largely the rear left, and no one can confirm or deny the relation this has with un-commanded descents. Unless someone wants to fully reverse the mini's code, were going to have to settle on not knowing what's really going on. We can hope that this puts an end to the un-commanded descents but only time will tell at this point.

hallmark007 Posted at 4-29 16:00
I think you’re well aware what I’ve said and what I mean, you seem to spend your time aimlessly defending what you’re saying, I think they’re so many variables regarding props loose props bad props damaged props props that fail the X-ray test props that need hauling through the ultrasonic , props put on new getting warning, props taken off one motor and put on a new motor, you’re so convinced this is only a prop problem that you have totally blinkered yourself.

Explain why dji would not insist in landing immediately on their warning, after all the big problem was drone couldn’t get home, but warning gives option to go home. So don’t ignore the fact that dji May well have optimized engines to try stop craft from descending.

Page-long response, usual personal attacks, yet no answer to a simple question...

I'm leaning toward thinking that, even when stored "correctly" within the Combo case, and even when the Mini is not actually resting its weight onto the rear props folded under its body, just the fact that the prop blades from one side are crossed over to mesh with the blades of the other motor somehow eventually causes the blades to permanently deflect.

With new blades installed on my left rear motor, the blades no longer slide easily over/under the blades of the right rear motor when the arms are folded back and the props blades are stowed crossed over each other under the body of the Mini.  Forcing them to mesh means one or the other side's blades are being bent up or down whenever "properly" stowed.

120ccpm Posted at 4-29 16:21
Page-long response, usual personal attacks, yet no answer to a simple question...

I made no personal attacks, but if the truth hurts your feelings you might need to get over that.
You’ll find your short question was answered in full yesterday so you’re well aware of what my post meant.

hallmark007 Posted at 4-29 16:34
I made no personal attacks, but if the truth hurts your feelings you might need to get over that.
You’ll find your short question was answered in full yesterday so you’re well aware of what my post meant.

Are you referring to un-matched pairs, with half-props on the same motor having different mold markings?