MM Folded Rear Prop Bending per DJI Instructions

[scro]

As per post #35, and I'll repeat it again here: when stored properly the blades do no touch the case.

I'm not sure why you think the case might need to be modified to put "less pressure" on the blades it isn't touching.

Theres a bump in the bottom of the case to support the belly of the drone. If you don't fold the blades as per instructions they can get squashed between the belly and the bump. If stored properly the blades are suspended in a void under the nose of the drone. Here's a few pictures to illustrate for any who don't have a mini/combo case:

 

[sar104]

So...I've read about all the mavic minis rear motor/prop issues...but never could replicate it. Until today...

I decided to store my mini in the case overnight (never have) and test fly it today during moderate wind.
Immediately the drone sounded more high pitch than I've ever heard it upon take off...and shortly after I was met with the "beeping esc change props " message.

Here's what I did. I rebooted the drone...and took off again immediately. No whine...no errors. Hmmmm...

Then I packed it back into the case...and then decided to try 1 more flight. As I was preparing to press takeoff...my phone rang and I took it...while pressing takeoff anyway. That's when I noticed something...

When the blades are crossed over one another as if it was just unpacked...there's a clicking noise as centrifugal force un-wraps them...and immediately the high pitch dound returned and stayed for the entire flight.
I tested this several times...either opening the blades manually and letting them be crossed while starting up.
Replicatable EVERY time.

My theory is...the drone senses the resistance (of the crossed blades) in the moment of startup..then immediately puts that engine into a limp mode until pilot lands it...even though the blades straightened themselves out immediately.
Also explains why changing blades seems to help...because they are swung out already before power-up.

Just fyi....EVERY time I replicated the esc/prop error..it was eith crossed back blades. EVERY time I swing them into position first...it became a different drone for the whole flight.
Knowing this...I turn the props out for easier spin up now..and the drone is perfect every time. Never changed props.
Just something to consider

That's an example of correlation but not causation. The motors are definitely not in any kind of limp mode - quite the opposite in fact - they are maxed out.

 

[Picklerick]

So...I've read about all the mavic minis rear motor/prop issues...but never could replicate it. Until today...

I decided to store my mini in the case overnight (never have) and test fly it today during moderate wind.
Immediately the drone sounded more high pitch than I've ever heard it upon take off...and shortly after I was met with the "beeping esc change props " message.

Here's what I did. I rebooted the drone...and took off again immediately. No whine...no errors. Hmmmm...

Then I packed it back into the case...and then decided to try 1 more flight. As I was preparing to press takeoff...my phone rang and I took it...while pressing takeoff anyway. That's when I noticed something...

When the blades are crossed over one another as if it was just unpacked...there's a clicking noise as centrifugal force un-wraps them...and immediately the high pitch dound returned and stayed for the entire flight.
I tested this several times...either opening the blades manually and letting them be crossed while starting up.
Replicatable EVERY time.

My theory is...the drone senses the resistance (of the crossed blades) in the moment of startup..then immediately puts that engine into a limp mode until pilot lands it...even though the blades straightened themselves out immediately.
Also explains why changing blades seems to help...because they are swung out already before power-up.

Just fyi....EVERY time I replicated the esc/prop error..it was eith crossed back blades. EVERY time I swing them into position first...it became a different drone for the whole flight.
Knowing this...I turn the props out for easier spin up now..and the drone is perfect every time. Never changed props.
Just something to consider

I think you’re on to something because I’ve noticed this as well. I’ve had to land immediately after take off a few times due to stability issues/erratic hovering. I’d take off again and it would fly fine after that, I always thought it was a quirk from hand launching because it never happens when I ground launch. But now that I think about it, I always expand the blades when I ground launch, which I don’t always do when I hand launch.

Edit: For the record, I’ve never had any uncommanded decents.

 

[steve_lyt]

my last word on this thead is how many people are careful?

 

[Cloudhopper]

Probably an obvious one, but removing the battery during storage would lighten the drone significantly and reduce any stresses on the props in the case -- if indeed this is a real problem.

 

[sar104]

Probably an obvious one, but removing the battery during storage would lighten the drone significantly and reduce any stresses on the props in the case -- if indeed this is a real problem.

It's unambiguously a real problem, and the weight of the battery isn't going to make a difference.

 

[scro]

my last word on this thead is how many people are careful?

Good question. A lot of problems discussed on here are as a result of people not being careful. Whether that is careful to check the weather conditions, careful to read and follow the instructions, careful to check the condition of their drone, careful in how they store it...etc...

 

[RichR]

In some ways other drones with fixed arms and one piece prop force you to be more careful about the props when you transport and store them. It's the convenience of the Mavic series' folding arms that maybe creates more opportunity for less care being taken.

 

[scro]

DJI's promotional videos (inc someone pulling a mini from a pocket) paint a quite optimistic picture that the Mini can be chucked around and thrown in a bag without any issues.

 

[AndreaBB]

As per post #35, and I'll repeat it again here: when stored properly the blades do no touch the case.

This could be true when you place the drone in, but if you shake the case and move it upside down the blades move too. The case is meant to bring the drone safely around, not to hold it on a shelf.

 

[scro]

And will the blades move enough to get themselves squashed between the drone and the pads in the case that hold the body of the drone securely?

 

[AndreaBB]

When folded rear blades could clearly move towards the back of the drone, so they could stuck in the case wedge and gets ruined.
Yes, a lot of “could”.

 

[scro]

I'm not convinced. When the lid is closed the pad on it presses down on top of the drone body, thus pressing the drone belly onto the pad that supports it from underneath. I struggle to see how a very light blade could force it's way in between the snugly fitting pad and drone body

 

[Phergie]

When I received my Mini, I noticed right away that the Combo Case was putting undue pressure on the props as folded per DJI's instructions, and figured that it couldn't be good for the props in the long run. I messed around with the prop orientation when placed in the case, and came up with an orientation for both the front and rear props in which neither came into contact with any of the internal foam blocks - they are essentially "free". I have attached photos of this orientation. Haven't had any problems with drone performance thus far...

 

[scro]

Interesting method which would work for me. However, I find that folding them as per instructions also works fine: Rear blades between the power button and gimbal guard, front blades between the DJI logo and the battery door. If that puts pressure on your blades your case must be different to mine.

 

[Ralle]

Interesting method which would work for me. However, I find that folding them as per instructions also works fine: Rear blades between the power button and gimbal guard, front blades between the DJI logo and the battery door. If that puts pressure on your blades your case must be different to mine.

Keep the mini open and pack only when you go on a trip !

 

[scro]

My mini has been kept in a closed FMC case for most of its "life" and so far no issues. I really think it comes down to HOW you store it in the FMC case.

I only take it out of the case to fly it or do maintenance, so it's probably been in the case for 5+ months at least.

 

[Zen Fly]

Hello,

After reading almost "half of the internet" I've print one clip for back props. Not being satisfied, the clip ended being remolded till it is now and I think is the best option for storing MM in fly more case.




But I've noticed that (with and without the clip) back left arm stay in a lower position relative to back right arm and BL prop slightly touch MM's body.



PS. sorry for my poor english.

 

[sar104]

Hello,

After reading almost "half of the internet" I've print one clip for back props. Not being satisfied, the clip ended being remolded till it is now and I think is the best option for storing MM in fly more case.

View attachment 100280
View attachment 100281

But I've noticed that (with and without the clip) back left arm stay in a lower position relative to back right arm and BL prop slightly touch MM's body.

View attachment 100282

PS. sorry for my poor english.

That should do the job. And once you have read the whole internet your English will be much better¡

 

[Zbip57]

[...] even when the Mavic Mini rear props are folded per DJI's instructions to fit in the Fly More case, they get bent which could be a contributor to the uncommanded descent issues that many of us have been having.[...]

Look what happens when one of the motors' props are rotated in per DJI's instructions. The props begin to make contact with the body and experience a very small bend to them.
View attachment 99602
I'm curious what other folks think about this.

I think you're on to something there, and agree with what you're saying. Even if you do take care to position the prop blades "correctly" into the troughs in the flymore case to ensure the case itself is not putting any pressure on the blades, I think the blades are still being bent just by forcing them to nest together like this.

I have always stored my Mini in its Flymore case between flights since its purchase in December with no apparent consequences. But on the very first flight since upgrading to v01.005 firmware I received the Motor Speed warning with instructions to replace the left-rear prop blades.

Prior to installing the new blades, the rear props always seemed to slide over/under each other to nest easily in the Flymore case. But I notice the new blades now cannot slide under/over the opposing motor's blades unless one side or the other is bent up/down.

I wish I had taken a "before" photo as well, because previously the blades slid together to nest easily together. But now, with new blades installed on the left-rear, and the original blades still on the right-rear, you can see that they can no longer nest together without deforming one side or other. Putting fresh right-rear blades would make it even more obvious.