Hi, I am looking for some advice on when and how to replace propellers.

A few flights ago the app said that the propellers was damaged I should hover the drone for a few minutes to see if it would sort itself out. Well after I did this a few times it was ok.

Took the mini to a river and launched it from a sailboat to capture some footage. The first launch was not successful because I didn't realize the boat was moving so it took off and hit me on the arm which resulted in a few drops of blood and the drone crashed on the boat. After regrouping the drone seemed to be fine I launched it from the stern of the boat by hand. It was all good some videos and pictures were captured. Man it was nice to see the boat from the above. What a beautiful sight. Being the first flight from a boat I decided to land the drone while the there was still plenty of juice left in the battery. The plan was to slow down the boat as much as possible (there is a thing called heave-to which will slows down a sailboat greatly) then either land the drone on the boat or catch it by hand astern. There are two big sails and all kind of riggings to content with. If you even see a sailboat you know what I am talking about. Anyway I started to fly the drone back manually. It is at this point I realized that the drone could not fly in the front and back direction and the distant continued to show 619m. The left and right motion seemed to be ok. Up and down is fine. With the drone disabled I rotated the drone so it could be flew back with just the left and right motions. After doing this for a few minutes it seemed the left and right motions are not performing too good either! Now panic set in. Thinking really fast I decided the most reliable option to recovery is to sail the boat back to the drone and catch it with a fish landing net that we happened to have on board. I do have the dji care plan so this way even if the drone is damaged at least I have the wreckage. And what a lucky coincidence the skipper of the boat brought the net since we were going to go crabbing afterwards! With some skilled manuvuering the boat was sailed right pass the drone and I caught it with the net in one swoop. To end the story our fortunate improved after the mishap. We caught 10 nice blue crabs for dinner.

The log showed message that "the motor was unable to rotate, check for objects blocking motor". It is a little wierd because there was obviously some wind and the drone seemed to be able to maintain it's position. I tried flying the drone afterwards it showed another error message that the "propeller rotating too fast" but the message disappeared after a while. The props seem to be ok visually. So here are my questions 1. is there anything wrong with the motor? 2. should all props be replaced at the same time since I can't tell which one is wrong.

Thanks for reading this story. I think I discovered another way to land a drone on a boat

Hello there omgnotagain. Thank you for sharing your experience in flying your DJI Mavic Mini and for reaching out. Since there was a crash that happened before. It would be best to contact our DJI support team at https://www.dji.com/support for further assistance. We have a team that will check the said drone and give out the best resolution for this issue. In addition DJI recommend that if the propellers were scratched or damaged, please replace then for safety purposes. Again, I am sorry for this trouble and thank you for your understanding.

Your props need replaced, look at previous articles on crashes and prop  speed issues.

Also look at the top article in this Forum "New Mavic Mini Safety Notification – “Motor Speed Error”
As you had error message that the "propeller rotating too fast"

omgnotagain,  Also try to clean out the motors, sometimes sand or dust get in them.

Thanks @videoeditman. I launched it again there is no error message anymore. I realized that the error at the end of the problematic flight was cause by the props hitting the net when it was caught. So there was no error I can see from the flight data.

I will follow the direction from one the posts to download the prop data to see if there is any difference in rpm among the motors. I must say even though the mini is great it seems to be high maintenance at least for me.

Hiya,

If you like upload your flightlog and DAT file for this flight.
log using > http://www.phantomhelp.com/LogViewer/Upload/.
DAT file, put a cloud link on here for your DAT file.\

DAT file contain motor data (rpm etc)   Both file will explain more.

PS error "motor was unable to rotate, check for objects blocking motor" is shown when RPM value gets lower than a tresshold value, this is not zero.So bit confusing as motor is still rotating when this error pops-up.

cheers
JJB

JJB* Posted at 9-8 11:42
Hiya,

If you like upload your flightlog and DAT file for this flight.

here's the log

https://www.phantomhelp.com/LogViewer/PDMFL6U1KOG5KWFS5L3K
Look at the last few minutes of the flight. The distance from home is basically unchanged. This distance is not correct as I moved closer to the drone and eventually caught it. Signal was not lost was able to move the drone up and down. I do not see any error in the log. Maybe a mulfunction of the controller?

omgnotagain Posted at 9-9 04:07
here's the log

https://www.phantomhelp.com/LogViewer/PDMFL6U1KOG5KWFS5L3K

Hi,

Nice flight!  

At the beginning one error : " Aircraft max power load reached. Decrease altitude and fly with caution. If this issue persists, Land immediately" (at13seonds in flight)
Only once so no problem.

Wind warning Once : " Lower altitude immediately and Return to Home manually | Strong wind warning. Aircraft unable to Return to Home automatically"  at 15m08s
Yep, typical for a MM, sensitive for (too much) wind.

Not a normal landing, indeed picked out of the sky!  good job.
Landing on a boat, fly backwards to yourself on the boat....and indeed   grab it while flying. (use gloves and eye facial protection)

cheers
JJB

Thanks JJB. Good to know it's all normal.