Mavic Mini prop has unstable shape ?

[Saigondroner]

Well the alternative is that they were deformed originally, which goes back to the observation that it would be rather surprising if the deformed props always end up on the rear motors.

Please tell me what to do, for your analysis, once these props arrive. They are coming from the same vendor that I have purchased CF props from before. They will have little discernible flex.

 

[sar104]

Please tell me what to do, for your analysis, once these props arrive. They are coming from the same vendor that I have purchased CF props from before. They will have little discernible flex.

Just do a hover test, and see if you can retrieve the DAT file before it disappears.

 

[Saigondroner]

Just do a hover test, and see if you can retrieve the DAT file before it disappears.

Yeah, I had a heck of a time with the EMP log...haven't forgotten ;-)

 

[Saigondroner]

Someone who has scuffed-up or damaged props should try to bend them by hand and see where the threshold is more or less and this way we can try to form a bit of extra pitch where needed and adjust accordingly. I'm just still super happy with my unit and don't wanna mess around with it at all.

The most I've done is just the FCC Hack to my CE version, as I fly in Sofia City and its extremely clustered with Wi-Fi. The FCC Hack on CE models does indeed extend the range of the CE version to about 1.3 km which is amazing and what I want in my city.

cool cool

Just some friendly advice--do not get carried away with DJI hacks. DJI is actively trying to stop drone hacks. They are the #1 drone maker, and Goverments are watching them. DJI knows this. A billion dollar company will force feed your MM with a FW update, and ground it.

Only the Mavic Pro 1, and earlier drones can be "modified", and DJI cannot affect the mods.

 

[old man mavic]

all i can add to this thread is since i put my home made front arm stiffeners on my drone i have had no more prop strikes on the body of the drone and no issues with it not taking off level from the pad, the props whether they go on the back or front motors are identical, they come in a pack of 4 two CC and two CW, and they are not labeled front or rear so one pack will do either

 

[Saigondroner]

all i can add to this thread is since i put my home made front arm stiffeners on my drone i have had no more prop strikes on the body of the drone and no issues with it not taking off level from the pad, the props whether they go on the back or front motors are identical, they come in a pack of 4 two CC and two CW, and they are not labeled front or rear so one pack will do either

What did you construct? I have thought about gluing CF along the sides of the front arms. Easy to obtain. But I can't see the point to 'Pimp my Mini" I'd rather tape laser pointers on my Tello.....

 

[old man mavic]

because i was having prop strikes i glued some thin strips to the back of the front arms to make them more rigid, i used an old bank card which was light and thin and easy to cut to shape

 

[Starz]

May not be applicable to the op’s issue, but may be of interest.
Also old man mavic could post a link to his work?

Pay attention! (I didn’t)

If you haven’t seen this one. https://forum.dji.com/thread-208212-1-1.html

mavicpilots.com

 

[Wild Drone Pilot]

OK, I am bored today so I did a small experiment on my Mini. I have noticed for some time that when hovering in a windless environment, the revolution speed of the motors at the back is significantly higher than those of the front motors. This is not good because it means the motors at the back will reach their speed limit sooner so the overall power of the craft is reduced.

I have been suspecting that the higher revolution speed is caused by the pitch of the props reduced for some reasons. To verify this I swapped the front props with those at the back and checked the motor speeds when hovering indoor.

Original prop installation :
View attachment 93302

Props swapped :

View attachment 93303

So what I have suspected turns out to be true ! The props at the back have lower pitch and after they are installed on the front motors, the revolution speed of the front motors becomes higher !

My Mini is very new, less than 10 flights. No crash or hard landing.

This opens up further questions :

1) How is the pitch of the props at the back changed ? can it be due to the fact that they are being sit on by the craft when stored inside the case that came with the drone ?

2) Does this explain the numerous reported crash cases of Minis in which some motors have the power maxed out and the craft failed to tilt to the commanded angle before it fell out of the sky ?

3) How can the problem be solved ? Are there any better props out there ? Hope third-party prop makers are listening.

Any comments ?

You have to smash the props together by folding them on top of each other to get them in the DJI case.

It must deform them in no time.

My Mini now seems to make more prop noise than at first! Only flew it like 3x so far.

 

[Deleted member 109934]

OK, I am bored today so I did a small experiment on my Mini.

3) How can the problem be solved ? Are there any better props out there ? Hope third-party prop makers are listening.

Any comments ?

I suspect the same about props and storage. I think mm props can get damaged from opening and closing the rear legs as well when stored improperly with load on the pros they will change flight characteristic. There is big difference between new and props after 20h of flight.

I’m collecting data now, It might take a time before I have good set, I will post my findings here. I will do some hover tests before and after. I’m almost convinced a lot of people damage their props completely acidenty without even knowing. Those props can’t take mp props abuse. folding them accidentally wrong way in to the box will make mm fly slightly differnet.
Your data set clearly indicates and confirms my suspicious.
Thanks for sharing.

 

[Deleted member 109934]

You have to smash the props together by folding them on top of each other to get them in the DJI case.

It must deform them in no time.

My Mini now seems to make more prop noise than at first! Only flew it like 3x so far.

because of that I got case just for drone itself, it is much easier to put the drone in that case Instead of original dji box.

 

[old man mavic]

May not be applicable to the op’s issue, but may be of interest.
Also old man mavic could post a link to his work?

Pay attention! (I didn’t)

If you haven’t seen this one. https://forum.dji.com/thread-208212-1-1.html

mavicpilots.com

see @Starz check your props? thread post#12

 

[Starz]

see @Starz check your props? thread post#12

Here’s the link to that one.

Checked your props?

Having a bit of an issue with the one I have. Please check your front props for chips on the ends and post results. Also make what sounds like a clicking noise when they hit the arm. Trying to determine if I’m the Lone Ranger. TIA. One other known to date.

mavicpilots.com

 

[SqFt]

Maybe the center of gravity from front to back is not centered exactly between the front and rear arms. Then to maintain stable flight, one end will need to spin faster than the other to maintain a steady position and support the greater weight. I seriously doubt the props are being deformed by the weight of the drone.

 

[new2mavic]

Maybe the center of gravity from front to back is not centered exactly between the front and rear arms. Then to maintain stable flight, one end will need to spin faster than the other to maintain a steady position and support the greater weight. I seriously doubt the props are being deformed by the weight of the drone.

I have suspected about that too. Mini has a Japanese version which weights only 199 gram. It has a lighter battery so may be the CG of the 249 gram version is slightly shifted to the back and the Japanese version slightly shifted to the front ? If that is the case, the revolution speed of the motors at the back should stay higher after the swapping of props .

 

[new2mavic]

I did some further "fine tuning" of the prop blades today. This is the situation at the beginning. The speed of the RFront motor is higher than the rest :



Then I swapped one blade of the RFront motor with one of those of the LBack motor. The blade swapped was just randomly selected. The speed of the four motors became very close when hovering indoor :

 

[Tieton]

I did some further "fine tuning" of the prop blades today. This is the situation at the beginning. The speed of the RFront motor is higher than the rest :

View attachment 93377

Then I swapped one blade of the RFront motor with one of those of the LBack motor. The blade swapped was just randomly selected. The speed of the four motors became very close when hovering indoor :

View attachment 93378

Where can you get these graphs from?

 

[new2mavic]

Where can you get these graphs from?

Pls check out this thread : Flight log retrieval and analysis guide

 

[Tieton]

Pls check out this thread : Flight log retrieval and analysis guide

Thanks, I know that thread and have tried free version of Airdata.
Which program you use for motor speed?

 

[new2mavic]

Thanks, I know that thread and have tried free version of Airdata.
Which program you use for motor speed?

CsvView. You can download it from CsvView Downloads. You will need to get the . DAT flight log files first