Mavic Pro Platinum had a moment

[kmohr3]

I was flying my MPP, that I have recently rebuilt and noticed a bit of a stutter while descending from 400 ft. At about 150 ft I noticed a bit of a hiccup, and then it carried on. I flew about 4 more minutes and brought it down and noticed a few nicks on one of the props, near the tips. I'm guessing maybe a small bird may have hit it. I honestly didn't see anything around or near it. The flight log didn't show anything, except some compass errors when it was near my driveway.

 

[MAvic_South_Oz]

..
Sounds like you were lucky there.

Were you recording video and had a chance to review on a larger screen ?
You can often see things that you don't on smaller phone or iPhone / tablet screens when flying or reviewing.

It could possibly have been a bee swarm or similar, even something small like that can damage a prop.

If it were me, I'd just change the full set, if they've been on a while they might be getting a little UV affected, which can make them brittle.

All the best with the MPP and a lot more flying, still fly my M1P.

 

[Yorkshire_Pud]

Where are the nicks, trailing edge or leading edge?
If you saw stutter then unless the impact hit the camera/gimbal the drone's actually 'stutter' must have been significant. Did you check the drone's and gimbal's pitch and roll in the csv of the log?
It might also be useful to have a look at the motor speeds in the DAT, though I don't know if their resolution is fine enough to pick up a speed change due to impact.

 

[kmohr3]

Unfortunately I wasn't running video at the time. The props were almost new - only about 5-10 flights on them. I just replaced upper and lower body shell and a LR motor arm after a crash - and I've been doing evaluation flights. I think what you said - maybe some bees or something.

Where are the nicks, trailing edge or leading edge?
If you saw stutter then unless the impact hit the camera/gimbal the drone's actually 'stutter' must have been significant. Did you check the drone's and gimbal's pitch and roll in the csv of the log?
It might also be useful to have a look at the motor speeds in the DAT, though I don't know if their resolution is fine enough to pick up a speed change due to impact.

 

[Starz]

Bees are not going to chip your props. Birds are probably going to cause more than just a prop problem.

 

[kmohr3]

Unfortunately I wasn't running video at the time. The props were almost new - only about 5-10 flights on them. I just replaced upper and lower body shell and a LR motor arm after a crash - and I've been doing evaluation flights. I think what you said - maybe some bees or something.

Where are the nicks, trailing edge or leading edge?
If you saw stutter then unless the impact hit the camera/gimbal the drone's actually 'stutter' must have been significant. Did you check the drone's and gimbal's pitch and roll in the csv of the log?
It might also be useful to have a look at the motor speeds in the DAT, though I don't know if their resolution is fine enough to pick up a speed change due to impact.

The nicks were on the leading edge of one prop, (at the gold tips), just 2 small nicks on each end. I don't think it hit the camera, but I did notice that the drone did a slight and momentary tip or wobble. The only thing out of the ordinary is a high-wind warning around the suspected time, (when the attitude indicator was at it's worst). The only other thing I noticed was for a second the battery cell deviation was flagged red, with a value of .137 for some reason? I used the txt file for the flight log - I think I'll try to read the dat file, maybe that will show more.

 

[Yorkshire_Pud]

Did you check the two pitches and rolls I mentioned?
Posting the log on the forum might an idea, someone might spot something you missed.

Also check the drones body for any marks under or in the 'path' of the blades' tips.
It has been suggested that blades or motor arms can bend during severe 'acrobatics'. If there are marks on the drone's body where the tips could contact the body then it might be that the drone was hit by a vicious gust, reacted and went to an extreme tilt causing the blades to contact the drone's body.
I do not know if this is possible with the MPP but .......

 

[Yorkshire_Pud]

I just replaced upper and lower body shell and a LR motor arm after a crash - and I've been doing evaluation flights.

Which arm was this prop on?
Have you checked that the each arm sits symmetrically with its right/left partners?
I crash a Mavic 2 and one front arm drooped, it turns out that a spigot protrudes from the top of the front arm pivot. For the drooping arm this spigot was bent on the and was forcing the arm to droop.
Also there is a plastic thrust washer ( black ) that sits on top of the arm, presumably to keep a gap between the top of the arm and the drones body, does the MPP have the same arrangement and did you have any spare washers left over at the end of the rebuild. With regards to the spigot, the MPP front arms appear to have the same arrangement, did you notice if the spigots were bent. BTW if you position the arm at the tipping point between spring-open and spring-shut the front arm pivots are probably very easy to remove and refit.

With regards to the rear arms I can't find a dismantling video that shows a clear shot of the naked end of a rear arm and I appreciate that the design of the MPP and Mavic 2 differ wrt the rear arm pivots but ..... On the Mavic 2 there is a travel limiting lug on the inner end of the arm's male-half of the pivot, it moves in a circumferential groove in the inner end of the female-half of the pivot. This lug seems prone to being broken off and that allows the arm to rotate when in the flying position. Since it appears that the female-halves of the rear arm pivots can be bought separately from the arms I would guess the male and female halves of the rear arm pivots can be separated. If so it might be any idea to check if there should such a lug and if so if it is present on both arms.
BTW, with the Mavic 2 when fitting the arm's male-half of the pivot into the female-half the lug slides in an axial groove in the bore of the female, meaning the arm has to be in a certain position to fit it and remove it, from memory this was the fully closed/ storage position.
If the MPP's rear arms have a similar lug there is probably as similar position requirement.