MOTOR SPEED ERROR MAVIC MINI

[RC_HC]

It is interesting to see that the new Mini 2 comes with a propeller holder that places the rear blades in a very similar stress-free position as in your design, not crossed over each other as they are in the Mini-1 Fly More case.

Really! I haven't seen that before.
The bottom reason, but the top ?! Is the old mistake made there again, or do I see it wrong?
You also need to plan some good solution for this.

 

[Zbip57]

No, the top blades are still stored crossed straight across the body. But those are okay like that, as the front motors are level with each other, so that doesn't bend the blades.

The rear motors, being canted outwards, force the blades to bend when they are crossed laterally across the body. So on the Mini 2 they no longer force them to mesh like that. Instead the Mini 2 comes in a soft carrying bag using a prop holder that positions the blades angled back, much like your design.

See at 2:30 in this video.

 

[RC_HC]

No, the top blades are still stored crossed straight across the body. But those are okay like that, as the front motors are level with each other, so that doesn't bend the blades.

The rear motors, being canted outwards, force the blades to bend when they are crossed laterally across the body. So on the Mini 2 they no longer force them to mesh like that. Instead the Mini 2 comes in a soft carrying bag using a prop holder that positions the blades angled back, much like your design.

See at 2:30 in this video.

I examined mine and I see me tops are also available at an angle.
That's not right either! If it weren’t at an angle, one blade would have to slide onto the top of the other. We are talking about 4 blade!
But for me, the upper engines make a slight angle.
The best solution is if the blades do not touch. Not on top!

 

[Ron Añejo]

Then access the flight log DAT file to plot the motor speeds using CsvView.

DAT files are supposed to be in \DJI\dji.go.v5\FlightRecord\MCDatFlightRecords on Android, yes? This folder is empty on my device. But I seem to remember that I have seen DAT files there in the past. Any idea why there are no DAT files now? And am I right in looking for DAT files on the phone and not anywhere else?

I would really like to see the motor rpms. I wasn't aware that this is possible before reading this post. BTW, I am obviously a classical victim of the left-rear problem, changed my propellers three times, they worked fine for a while and then the motor problem reappeared. Couldn't figure out what was happening. I also had a an uncontrolled “landing” – fortunately (?) in soft mud and therefore no damage except for excessive amount of dirt on the Mavic Mini.

 

[Zbip57]

DAT files are supposed to be in \DJI\dji.go.v5\FlightRecord\MCDatFlightRecords on Android, yes? This folder is empty on my device.

In the "Flight Data Center" make sure that "Auto Flight Record Backup" is disabled.

When you sync your Flight Data to the DJI backup servers, it deletes those DAT files. I keep my Auto Backup disabled, and that way all my DAT files remain on the phone. A new DAT file is added each time the Mini is powered up.

 

[Ron Añejo]

This folder is empty on my device.

I did a test flight (just hovering), and now suddenly there were two DAT files immediately after the flight! A little bit later one of the DAT files was gone. I will disable “Auto Flight Record Backup”. Thank you very much to Zbip57 for pointing this out.

Anyway, I could check the motor RPMs and can confirm that a new pair of propellers reduces the motor speed even on motors not affected by the “rear-left” problem.

 

[Zbip57]

Would these propeller holders from the MM2 fit on the original MM? If so, I might try to get myself one and prevent the props from distorting again...

Ideally the blades should be stored positioned longitudinally along the sides of the Mini's body, not crossed laterally to mesh folded over/under each other. As long as the tips of the blades on one motor are not crossed under/over the tips of the blades of the opposite side's motor, it should be okay.

I don't have access to a Mini-2. Are the rear motors still mounted at the same angle canted outwards? From the video link above, it looks like the prop holder positions the blades at about a 45° angle, so the tips are barely touching each other, not crossed over each other.

 

[Petepoing]

It's not only the Fly More case that's causing the prop deformation. It's also the original plastic shell which non-Fly More Minis are shipped in. Common to both is the way the blades are crossed when stored.
The latest firmware (v01.00.0500) introduced a new feature that alerts you to excessive motor speeds and instructs you to replace the prop blades on the identified motor. The reason the warning is sometimes triggered even on brand new Minis, and even on Minis with recently replaced propellers, is due to how the blades are bent while stored in the crossed position.

Thank you Zbib57, that was very helpful since I had that error too, and I didn't know whot cused it.

 

[Niterunnr]

My basic Mini2 (non flymore) which does not include a carry case, still shipped with both prop sets taped together laterally (across the body).
I purchased a third party case and added padding at the rear where the font legs rest when folded to keep the blades from touching the bottom of the case.
I’m thinking another great option would be a case that stores the mini on it’s side so the blades rest or hang free depending on orientation.
My laptop died so unless I can upload dat files from my iPhone, I cannot check motor speeds. No flight issues so far.
Still can’t beleive DJI messed this one up so bad and feel they should offer a free solution to all registered owners.

 

[Niterunnr]

My basic Mini2 (non flymore) which does not include a carry case, still shipped with both prop sets taped together laterally (across the body).
I purchased a third party case and added padding at the rear where the font legs rest when folded to keep the blades from touching the bottom of the case.
I’m thinking another great option would be a case that stores the mini on it’s side so the blades rest or hang free depending on orientation.
My laptop died so unless I can upload dat files from my iPhone, I cannot check motor speeds. No flight issues so far.
Still can’t beleive DJI messed this one up so bad and feel they should offer a free solution to all registered owners.

 

[FlyBackOU812]

It's not only the Fly More case that's causing the prop deformation. It's also the original plastic shell which non-Fly More Minis are shipped in. Common to both is the way the blades are crossed when stored.

The latest firmware (v01.00.0500) introduced a new feature that alerts you to excessive motor speeds and instructs you to replace the prop blades on the identified motor. The reason the warning is sometimes triggered even on brand new Minis, and even on Minis with recently replaced propellers, is due to how the blades are bent while stored in the crossed position.

The label in the Fly More case shows the left-rear blades (A&B) folded under the right-rear blades when the Mini is stored with arms folded.
View attachment 105928

First off, that label is already inaccurate as it is impossible to position them like this (with A under B) since the leading edge of A cannot be forced under the trailing edge of B.
View attachment 105929

Regardless of that particular inaccuracy, the Mini is shipped with both left-rear blades (A&B) folded under the right-rear blades. That is why the Motor Speed Error most often first identifies the left-rear blades as needing replacement, even on brand new Mavic Minis.

My Mini was always stored (with blades crossed) in its Fly More case, and I was never aware of any prop issue until my first flight after updating to the latest firmware. The new Motor Speed Error instructed me to replace the left-rear prop blades.

Here's a photo comparing the new left-rear blades versus the old original right-rear blades. Note how the fresh left blades are straight and now stand higher than the old right blades. The right-rear blades easily slide under the left blades when crossed.
View attachment 105918

Next is a photo with both the left-rear and right-rear props replaced with fresh new blades. Now you can see how both sides cross, with neither side wanting to fit under the opposite side when folded together. Blade #1 is straight and un-deflected, while blade #2 has to be bent down in order to force it to nest under the opposite side's blades.
View attachment 105932

Here is someone else's photo of a Mini still in its plastic shipping tray, with DJI's paper band securing the prop blades in their stowed crossed position.
View attachment 105933

And this is the how the rear prop blades look, straight out of the box, with the paper band still keeping the blades fixed in their "proper" stowed configuration. Clearly the left-rear blades are bent to fit under the right-rear blades like this.
View attachment 105934

That is why the left-rear blades are almost always the first to trigger the Motor Speed Error warning. If you store yours the other way around, with the right-side blades bent under the left-side blades, then you'll likely have the Motor Speed Error identify the right-rear motor first.

So why do the front motors hardly ever trigger a similar warning? It's because of the way the motors are mounted canted at different angles. The rear motors are canted outboard, whereas the front motors are not. The fronts are instead canted rearward.View attachment 105935

With the arms folded, you can see how much the rear motors are canted outboard. That means the propeller blades must cross when nested inboard across the body. New prop blades can only be forced to stow nested together if one side or the other is forced to bend under/over the other side.
View attachment 105936

The front motors instead are level with each other, not canted outboard.
View attachment 105937

The front propeller blades can therefor be stowed nested together without imposing any bending stress on the blades.
View attachment 105938

What a great explanation of why the problems occur in flight. Forgive me, I have some reading issues, so with all the information I missed if you supplied the recipe for the CORRECT way to fold the rear props in to avoid distortion. If you did, could you please repost (just the proper folding instructions). TIA

To answer your question you had for me about how my blades compare to the ones posted... answer.... identical and ive been storing mine cross body since day one and these props on this mini thats now like 6 to 8 months old have been stored in the heat of my truck on occasions wrapped up tight with velcro and never changed. Ive got like 100 hours flight time on this one at least. I just haven't yet figured out how to share the pics with you yet lol I'm gonna work on that right now

 

[FlyBackOU812]

It's not only the Fly More case that's causing the prop deformation. It's also the original plastic shell which non-Fly More Minis are shipped in. Common to both is the way the blades are crossed when stored.

The latest firmware (v01.00.0500) introduced a new feature that alerts you to excessive motor speeds and instructs you to replace the prop blades on the identified motor. The reason the warning is sometimes triggered even on brand new Minis, and even on Minis with recently replaced propellers, is due to how the blades are bent while stored in the crossed position.

The label in the Fly More case shows the left-rear blades (A&B) folded under the right-rear blades when the Mini is stored with arms folded.
View attachment 105928

First off, that label is already inaccurate as it is impossible to position them like this (with A under B) since the leading edge of A cannot be forced under the trailing edge of B.
View attachment 105929

Regardless of that particular inaccuracy, the Mini is shipped with both left-rear blades (A&B) folded under the right-rear blades. That is why the Motor Speed Error most often first identifies the left-rear blades as needing replacement, even on brand new Mavic Minis.

My Mini was always stored (with blades crossed) in its Fly More case, and I was never aware of any prop issue until my first flight after updating to the latest firmware. The new Motor Speed Error instructed me to replace the left-rear prop blades.

Here's a photo comparing the new left-rear blades versus the old original right-rear blades. Note how the fresh left blades are straight and now stand higher than the old right blades. The right-rear blades easily slide under the left blades when crossed.
View attachment 105918

Next is a photo with both the left-rear and right-rear props replaced with fresh new blades. Now you can see how both sides cross, with neither side wanting to fit under the opposite side when folded together. Blade #1 is straight and un-deflected, while blade #2 has to be bent down in order to force it to nest under the opposite side's blades.
View attachment 105932

Here is someone else's photo of a Mini still in its plastic shipping tray, with DJI's paper band securing the prop blades in their stowed crossed position.
View attachment 105933

And this is the how the rear prop blades look, straight out of the box, with the paper band still keeping the blades fixed in their "proper" stowed configuration. Clearly the left-rear blades are bent to fit under the right-rear blades like this.
View attachment 105934

That is why the left-rear blades are almost always the first to trigger the Motor Speed Error warning. If you store yours the other way around, with the right-side blades bent under the left-side blades, then you'll likely have the Motor Speed Error identify the right-rear motor first.

So why do the front motors hardly ever trigger a similar warning? It's because of the way the motors are mounted canted at different angles. The rear motors are canted outboard, whereas the front motors are not. The fronts are instead canted rearward.View attachment 105935

With the arms folded, you can see how much the rear motors are canted outboard. That means the propeller blades must cross when nested inboard across the body. New prop blades can only be forced to stow nested together if one side or the other is forced to bend under/over the other side.
View attachment 105936

The front motors instead are level with each other, not canted outboard.
View attachment 105937

The front propeller blades can therefor be stowed nested together without imposing any bending stress on the blades.
View attachment 105938

What a great explanation of why the problems occur in flight. Forgive me, I have some reading issues, so with all the information I missed if you supplied the recipe for the CORRECT way to fold the rear props in to avoid distortion. If you did, could you please repost (just the proper folding instructions). TIA

To answer your question you had for me about how my blades compare to the ones posted... answer.... identical and ive been storing mine cross body since day one and these props on this mini thats now like 6 to 8 months old have been stored in the heat of my truck on occasions wrapped up tight with velcro and never changed. Ive got like 100 hours flight time on this one at least. I just haven't yet figured out how to share the pics with you yet lol I'm gonna work on that right now

 

[Shlomo]

I have the same error for some time. I replaced the Left Rear blade twice but still i get the error.
After reading this forum, I flight the MM for about 15 minutes in my room to test it. There was no error.
I looked at the aircraft dat file (using DatCon) and figure out that indeed this rotor speed is higher (about 25% from the other)
Motor:Speed:RFront 9949.0
Motor:Speed:LFront 9375.0
Motor:Speed:LBack 12521.0
Motor:Speed:RBack 10684.0

It looks like there is a problem with this rotor - what can i do ?

Thanks

 

[FlyBackOU812]

YES the left motor. changed the blades twice and stills happened. Now I do not do any thing about it, I do not have any performers problems.

The only reason people were confusing the issue being with the update was because thats when they originally got the update that told the issue. They may not have noticed their drones motor speeds were higher than they should have been but as soon as the new update downloaded it could speak to you and tell you in your language which happened to be in a warning. There was no way to tell you b4 that because it hadn't been told to. Thats just logical

 

[FlyBackOU812]

I flew my Mini a half- dozen flights or so, after getting the warning, before changing the props out. Warning went away immediately and now I store my MM anywhere but in the FM case.

Thats because centrifugal force, forced it to straighten itself back to it original and higher heated formed shape which it wants to do anyway. A warp from it just being heated a little is most likely going to be able to go back to its molded form. A molded form that was created by much higher heat will have more "memory" of that form than it would a warped heat that was much cooler. So if you add a little daytime heat to them and turn motors on, centrifugal force along with almost any heat will force them back to their molded form. Id be willing to bet the millions of props thrown away were still ok they just needed a small amount of heat and to hover a few minutes

 

[FlyBackOU812]

Where my finger is pushing would be sitting on the flat part of the fly more case in between the 2 motor cut outs which is exactly where the props are. It cannot push past that point. Im pushing at least 250 grams of pressure so the bottom of the case will not ever touch any other part of those props even with the weight of 10 mini's. Ghe material in the velcro is more than enough to fill the small gap of air between the body and that part of props. In the next video I share you will see how easily those props intertwine themselves effortlessly with any bending or forcing into place. I litterally only tap the back of my finger and barely touch them to get them into velcro position. After that they arent moving. And if you look at the pics of the shape of them they are exactly as brand new ones. The tips are even just as high as the ones I see here in the thread so its not as if mine are deformed in anyway that might allow them to go into place easier than a brand new set would. Theres enough play the motor and where screws mount the props to allow for even more than im asking out of it with the velcro. Only place that isnt exactly perfect is the tip of the one prop that rest under the other one. But again, there's enough play in there to handle that and morehttps://youtu.be/Ipqa3T5HSY8

 

[FlyBackOU812]

Where my finger is pushing would be sitting on the flat part of the fly more case in between the 2 motor cut outs which is exactly where the props are. It cannot push past that point. Im pushing at least 250 grams of pressure so the bottom of the case will not ever touch any other part of those props even with the weight of 10 mini's. Ghe material in the velcro is more than enough to fill the small gap of air between the body and that part of props. In the next video I share you will see how easily those props intertwine themselves effortlessly with any bending or forcing into place. I litterally only tap the back of my finger and barely touch them to get them into velcro position. After that they arent moving. And if you look at the pics of the shape of them they are exactly as brand new ones. The tips are even just as high as the ones I see here in the thread so its not as if mine are deformed in anyway that might allow them to go into place easier than a brand new set would. Theres enough play the motor and where screws mount the props to allow for even more than im asking out of it with the velcro. Only place that isnt exactly perfect is the tip of the one prop that rest under the other one. But again, there's enough play in there to handle that and morehttps://youtu.be/Ipqa3T5HSY8

 

[FlyBackOU812]

 

[FlyBackOU812]

See that little airgap in the middle of 2 perfectly equal Props? Thats where the velcro will be so there will be no closing of that gap

 

[FlyBackOU812]

As you can see I've been storing mine this way through the heat of the summer flying it hundreds of times so that means hundreds of times the velcro has been put on and taken off and stored each time and as you see they are perfect in every way