Dear Valued Customers,

To ensure a safe and enjoyable flying experience, we have added a new safety notification feature on the Mavic Mini in the latest v01.00.0500 firmware. This new feature lets customers know when propellers need to be inspected or replaced.  
                                                   

【Potential Notification】 While operating their Mavic Mini, some customers may receive a notification on the DJI Fly app with the message “Motor Speed Error”

  

【Reason for notification】When the propellers are bent or damaged, the aircraft propulsion may be reduced and not perform as intended. The new Mavic Mini propeller safety inspection feature is capable of detecting this and sending a notification to the pilot with a “Motor Speed Error” message.

  

【Resolving the error notification】Please land the aircraft as soon as possible and check if the corresponding propellers are visibly damaged, bent, chipped. If the propellers are slightly misshapen, can straighten them out and retest to ensure the issue has been resolved. If the propellers show signs of major damage, chipped or bent, please replace them before flying.

  

Note: To help prevent this from occurring, pilots should follow the proper storage procedure for the aircraft. For reference, please refer to the image below. Please notice the placement of the rear arm propellers. Make sure the propellers are folded horizontally so that they are not pressed down upon during transportation. Pilots are also recommended to check the aircraft propellers before every flight.

  
  

Thank You DJI support... personally I wouldn't rely on users to check if the propellers are bent or even (wondering what's intended) straighten them out, because I've seen this already happening when the users identify propellers as good even when they are not and insist that the firmware is faulty up to the point of downgrading to the next previous version that didn't have the safety motor speed control.

The best advice I could personally give to those that have the "Motor speed error" is to just replace the propellers and keep replacing them for every propeller that is being flagged by software.
If you really have to judge a propeller do it against a new set that you know is good. Even brand new sealed sets can become flattened if not properly stored.


How I did compare my set. I do not advise to do it normally but certainly can be a good practice when one gets a motor speed error.

For DJI to publish this message verifies that improper storage in the Fly More case is one of the causes for deformed propellers. Too much inaccurate anecdotal information being published in this forum.  Nice to finally see some communication.  

Occams Razor Posted at 5-7 20:18
For DJI to publish this message verifies that improper storage in the Fly More case is one of the causes for deformed propellers. Too much inaccurate anecdotal information being published in this forum.  Nice to finally see some communication.

i have the fly more kit case but maybe the reason why i don't have the prop issue is because i never transport my drone in the case.  in fact, i have never folded my drone arms.  i added strobes to the arms and a strapped a beacon to the rear leg which does not permit folding.  these can come off but to me, they are semi-permanent.  everywhere i take my drone, it is open and flat.  not so inconvenient once you get used to it.  i can definitely see where getting use to over "handling" the drone will ultimately damage things.

DJI, explain how it is possible that 99% of users have the same problem with the rear left engine? I think that is not possible. I think the latest fw has something wrong. If it’s really a safety feature, it doesn’t work the way it should. Yesterday (my fault) the drone hit a tree branch. One rear propeller broke in half after the impact. To my surprise, the drone continued to fly without problems. The sound from the propellers changed a bit. Even after such an accident, I did not receive any "engine error" message. Why?

Thank you for provide information about the issue.

Although I see this notification as an advantage, I still believe it should be retested as so many Mavic Mini pilots have reported issues. I believe DJI should ensure the notification regarding the props is accurate.

The MM pilots have tried different methods and have got different results. For example, I switched the props from the rear left to the front right and I got no error. Had the props been bent or damaged, I’d have gotten the error from the front right motor.

Thanks for the explanation. Is it possible to receive the torque (Nm) to use for the correct fixing of the screws? Thanks Mario

Occams Razor Posted at 5-7 20:18
For DJI to publish this message verifies that improper storage in the Fly More case is one of the causes for deformed propellers. Too much inaccurate anecdotal information being published in this forum.  Nice to finally see some communication.

Thanks for the update!

Nice info but there is more to fix, well just my opinion!

I had a uncontrolled descent once, during this descend the 4 motors were spinning down, so it dropped height ofcourse. a height error in the DAT file.

After this, i am still flying with the same original 8 blades, never happend again.
(but i do watch more at the app to see the height than i used to do)

cheers
JJB

Well, this confirms what we knew, that the FW update was meant to warn about bad props that cause motors to overspeed, but it doesn't explain why brand new drones exhibit the issue.

Donsir_LTU Posted at 5-7 23:12
DJI, explain how it is possible that 99% of users have the same problem with the rear left engine? I think that is not possible. I think the latest fw has something wrong. If it’s really a safety feature, it doesn’t work the way it should. Yesterday (my fault) the drone hit a tree branch. One rear propeller broke in half after the impact. To my surprise, the drone continued to fly without problems. The sound from the propellers changed a bit. Even after such an accident, I did not receive any "engine error" message. Why?

Not all bad props increase the rpm, this warning only trips at high rpm.

Donsir_LTU Posted at 5-7 23:12
DJI, explain how it is possible that 99% of users have the same problem with the rear left engine? I think that is not possible. I think the latest fw has something wrong. If it’s really a safety feature, it doesn’t work the way it should. Yesterday (my fault) the drone hit a tree branch. One rear propeller broke in half after the impact. To my surprise, the drone continued to fly without problems. The sound from the propellers changed a bit. Even after such an accident, I did not receive any "engine error" message. Why?

...yep...100% with you.

My props are all schmucked out...especially rears...and still originals...

No probs whatsoever...flies as new...meh!
...me think there is a factory problem with certain machines and DJI is trying to do "DAMAGE CONTROL"

I have a large rubber band on the length of the Mini to hold the propellers in place top and bottom like the picture when I store them back in the case that came with the fly more kit because they won’t stay in the position you put them in to put them back in the case. It seems to work pretty well! Thanks for the notification.

The Saint Posted at 5-7 22:59
i have the fly more kit case but maybe the reason why i don't have the prop issue is because i never transport my drone in the case.  in fact, i have never folded my drone arms.  i added strobes to the arms and a strapped a beacon to the rear leg which does not permit folding.  these can come off but to me, they are semi-permanent.  everywhere i take my drone, it is open and flat.  not so inconvenient once you get used to it.  i can definitely see where getting use to over "handling" the drone will ultimately damage things.

What kind of case do you use then for transporting your drone, if you don't mind sharing?

Thanks for this information

m80116 Posted at 5-7 20:08
Thank You DJI support... personally I wouldn't rely on users to check if the propellers are bent or even (wondering what's intended) straighten them out, because I've seen this already happening when the users identify propellers as good even when they are not and insist that the firmware is faulty up to the point of downgrading the next previous version that didn't have the safety motor speed control.

The best advice I could personally give to those that have the "Motor speed error" is to just replace the propellers and keep replacing them for every propeller that is being flagged by software.

Do you mind explaining to a newbie what differences do you see between the used propellers and the new one in your pictures?  
I could see a difference in the exploded view on the Rear Right II that looks bent upwards, but that could be the result of the angle of the picture.Thanks in advance.

Richard Hopkins Posted at 5-8 03:25
I have a large rubber band on the length of the Mini to hold the propellers in place top and bottom like the picture when I store them back in the case that came with the fly more kit because they won’t stay in the position you put them in to put them back in the case. It seems to work pretty well! Thanks for the notification.

Thanks for the tip.

JJB* Posted at 5-8 00:47
Nice info but there is more to fix, well just my opinion!

I had a uncontrolled descent once, during this descend the 4 motors were spinning down, so it dropped height ofcourse. a height error in the DAT file.

I actually think that might have been fixed with latest FW.

Thanks DJI

I have the error message using firmware .500.  I don't have the error message on .400 firmware.  I have a new drone.  How is it the storage?

UK01 Posted at 5-8 05:48
I have the error message using firmware .500.  I don't have the error message on .400 firmware.  I have a new drone.  How is it the storage?

400 didn't have the warning in it. Also, it isn't the storage, unless you store your drone with the props stocking out when you put it in the case. Almost all of us have the same case and haven't had an issue since we bought the drone. The instructions for folding the props before you put the drone in the case are the same instructions that came with the case.

As to why your prop has issues, assuming you stored your drone in the case properly, there is some variance in the props coming from the factory.

Deucalion Posted at 5-8 05:55
400 didn't have the warning in it. Also, it isn't the storage, unless you store your drone with the props stocking out when you put it in the case. Almost all of us have the same case and haven't had an issue since we bought the drone. The instructions for folding the props before you put the drone in the case are the same instructions that came with the case.

As to why your prop has issues, assuming you stored your drone in the case properly, there is some variance in the props coming from the factory.

So it seems DJI need to enhance the QC of their prop production.

hallmark007 Posted at 5-8 04:55
I actually think that might have been fixed with latest FW.

i hope so....  so far so good  ;-=)

flcusat Posted at 5-8 03:32
What kind of case do you use then for transporting your drone, if you don't mind sharing?

no case.  i simply carry it freely.

I am also not storing MM in my case (fly more combo) Rather I just leave it unfolded on top. I use the case just for transport.

I play the devil's advocate role here: you may get the motor speed error on the left because it maybe the first one to be checked or the circuitry might have marginally more resistance driving that motor, or it might even be that the left rear is the heaviest part and it needs a slightly stronger lift to stay level. Many have already proven replacing the props flagged that they were indeed no good anymore.

I think one should replace the props when prompted, only if the swap wouldn't lead to any appreciable result it might be the case of questioning whether there is an underlying problem. Chances are there isn't as long as the replaced props are new and have not been flattened by incorrect storage and handling.

My drone is pretty new (bought few days ago). Flew few times and got an rotor error with rear left engine. Propeller seems to be completely perfect and unbent. Can't see any difference to any other propellers.
It's really weird that this is not a bug in a software....

NeuTronas Posted at 5-8 11:51
My drone is pretty new (bought few days ago). Flew few times and got an rotor error with rear left engine. Propeller seems to be completely perfect and unbent. Can't see any difference to any other propellers.
It's really weird that this is not a bug in a software....

Have you tried replacing the props on the motor that was flagged as "speed error" ?

Have you tried to unmount those props and compared them pinned down from the screw hole against the new set included with every Mavic Mini ?

m80116 Posted at 5-8 12:31
Have you tried replacing the props on the motor that was flagged as "speed error" ?

Have you tried to unmount those props and compared them pinned down from the screw hole against the new set included with every Mavic Mini ?

No, but I was flying few hours ago just completely fine without any errors and after replacing the battery suddenly it broke.

It's just too big of a coincidence that so many people get this issue with the exact same error and faulty propeller. DJI please look carefully at this problem. I'll try to refresh firmware tommorow, if it doesn't help, I'll try switching the propellers.

You can spare yourself the time and effort. There no way a firmware update can be botched only to produce a motor speed error... an error specifically introduced by DJI to address problems that were previously hidden from user view, which is exactly what is happening. It's a firmware specifically designed to BRING OUT problems to prevent WORSE CONSEQUENCES.

It's a NOBLE and NOTABLE effort from DJI.

Your MM is probably in the grey area of almost triggering the error... you should replace the propellers on the affected ESC (motor) as INSTRUCTED, no flimflam.

Great pre-flight feature, but the biggest problem is that this error occurs in mid-flight ...

Hugs

m80116 Posted at 5-8 10:47
I play the devil's advocate role here: you may get the motor speed error on the left because it maybe the first one to be checked or the circuitry might have marginally more resistance driving that motor, or it might even be that the left rear is the heaviest part and it needs a slightly stronger lift to stay level. Many have already proven replacing the props flagged that they were indeed no good anymore.

I think one should replace the props when prompted, only if the swap wouldn't lead to any appreciable result it might be the case of questioning whether there is an underlying problem. Chances are there isn't as long as the replaced props are new and have not been flattened by incorrect storage and handling.

Besides rear possibly being heavier...
Normal flying is forward.  Flying slowly forward requires rear of MM to be slightly elevated above the nose of MM.  Flying faster forwards requires rear to be more elevated above the nose.   Putting more strain on rear props than front props.

Potential test...
Using a Left Rear prop flagged as bad by FW, put prop on Right Front motor.  Make sure Left Rear motor has a known good Prop.
Fly drone backwards  for entire flight, and see if FW flags Right Front motor as having excessive RPMs.  

NeuTronas Posted at 5-8 11:51
My drone is pretty new (bought few days ago). Flew few times and got an rotor error with rear left engine. Propeller seems to be completely perfect and unbent. Can't see any difference to any other propellers.
It's really weird that this is not a bug in a software....

Those with Mavic Mini's in grey area - sometimes problems, sometimes not.
May have to do with weather conditions they are flying in.

Mavic Mini flying forward against a head wind is going to need more thrust, putting additional strain on possibly bad blade(s), causing them to flatten.

Sunny hot weather could make black plastic of blades soften, just enough to cause blade to bend excessively, causing them to flatten.

Junior SBC Posted at 5-8 17:34
Great pre-flight feature, but the biggest problem is that this error occurs in mid-flight ...

Hugs

Suggest re-reading the warning.  Warning can occur during flight, thus it is not a pre-flight only feature.

NeuTronas Posted at 5-8 11:51
My drone is pretty new (bought few days ago). Flew few times and got an rotor error with rear left engine. Propeller seems to be completely perfect and unbent. Can't see any difference to any other propellers.
It's really weird that this is not a bug in a software....

So, I've refreshed my firmware update, recalibrated everything. And the error disappeared. Well, that's a fix for now until DJI releases another update, I guess.

NeuTronas Posted at 5-8 11:51
My drone is pretty new (bought few days ago). Flew few times and got an rotor error with rear left engine. Propeller seems to be completely perfect and unbent. Can't see any difference to any other propellers.
It's really weird that this is not a bug in a software....

It’s not a bug but it doesn’t mean there is anything wrong with your prop. Above instruction from dji is to check your prop for damage, repair if possible and change if damaged.
There is no invisible problem with props, it’s a myth spread by those who love to spread myths, I see the latest is that your props are melting, that usually comes from people who don’t own or fly mini.

So check props as above thoroughly including if it has somehow magically flattened itself while it resisting wind , flat props can and will cause problems but flying won’t ever flatten them.
To many myths trying to scare people and considering we have seen no problems since last update it seems strange why the same people keep touting the same old myths.

hallmark007 Posted at 5-9 03:35
It’s not a bug but it doesn’t mean there is anything wrong with your prop. Above instruction from dji is to check your prop for damage, repair if possible and change if damaged.
There is no invisible problem with props, it’s a myth spread by those who love to spread myths, I see the latest is that your props are melting, that usually comes from people who don’t own or fly mini.

...well said

See yet another attempt to mislead others from DJI's prop problem by taking member's remarks "out of context" or by using hyper-exaggeration to discredit members.


Little review:
【Reason for notification】When the propellers are bent or damaged, the aircraft propulsion may be reduced and not perform as intended.
Nothing from DJI about possible other causes for "Motor Speed Error", such as bad ESC, low battery power, bent arms, or some of missing Dark-Matter.  Blades be it!


Of course blades of a propeller can be bent or damaged by pilot.  Through, improper storage (as Notification details), carless handling, grazing of shrub, or crash landing.

However those possibilites do not explain why brand new Mavic Minis have been reported as flagging a bad prop when running 0500 FW.  Nor does it explain why brand new spare prop, (pair of matched blades), installed in place of flagged bad prop, have also been reported as being bad.  Not all cases, just some.


Both of those point to bad batch(es) of blades from factory, most likely blades being CCW (for Left Rear and Right Front motors).  Since bad blades are not (or were not) being detected at factory, one can assume problem with bad blades is not visually obvious to trained expert's eyes.

Using some, of aforementioned hyper-exaggeration we can say, damage to blades is Invisiable.

Hello, I have error ESC 30128, it's like motor speed problem, how to clear which one should I replace. I checked all propellers, and they looks same, not bended