Finally replacing props on my mini

[scro]

I've had my mavic mini for over 2.5 years and have finally got to the point where I need to replace any of the props. It looks like I've chipped the leading edge of 3 blades while doing a very close pass of a bush in my garden (it was intentional )

I've stored my drone exclusively in the much maligned flymore case and never had an issue with deformed props. However, I have always taken care not to trap the blades between the drone and the padding, even from before the deformed blade/uncommanded descent issues became apparent.

Anyone else still flying their mavic mini on its original props?

 

[old man mavic]

i had my mavic mini when they were first released ,and it was only this year ,before the so called spring weather improved enough for me to get out and fly again ,that like you i decided to do a complete prop change , mainly because i had several sets of spare props that i had purchased before they started to become harder to get ,i am talking about genuine DJI ones
and after nearly two and a half years of use ,i thought they had done their job ,and retired them to the back up spares for a rainy day box

 

[Yorkshire_Pud]

Not original here, mine were deformed on arrival, but certainly relatively old.

 

[scro]

Mine was also ordered on release day so is as "old" as any mini out there. I know lockdown felt long, but it's only 2.5yrs since the MM1 was released. I've just used some of the spare blades that came with the kit. Other than the chips on the leading edge both front and back props seem to be the same shape/curvature/angle as the fresh ones. hubs are in good condition with the same amount of play.

Having them deformed on arrival isn't cool Thanks, DJI, for packing the drone well

 

[Phantomrain.org]

So it never fails my cats get to the Props , so I am replacing them out all the time.
Funny thing is the bite marks on the Props never really affected any of the drones when flying .

Phantomrain.org
Gear to fly in the Rain. an stay away from Cats.

 

[old man mavic]

Mine was also ordered on release day so is as "old" as any mini out there. I know lockdown felt long, but it's only 2.5yrs since the MM1 was released. I've just used some of the spare blades that came with the kit. Other than the chips on the leading edge both front and back props seem to be the same shape/curvature/angle as the fresh ones. hubs are in good condition with the same amount of play.

Having them deformed on arrival isn't cool Thanks, DJI, for packing the drone well

yes have amended my post i received mine on the 18th November 2019 but it does seem a lot longer that that to me anyway put it down to old age,its my MPP that i had in 2018

 

[scro]

I had to count how many years it was It kinda feels like it was longer than that for me too.

The original props could probably have stayed on. It was flying fine after the "scenery editing" but since I've got fresh props and I need to use them some time before the batteries die of old age or something

OMM - I see you've acquired a nice new mini3 - how much "quieter" would you say it is than your MM1 (am meaning in the subjective/qualitative sense rather than the technical dB numbers)? I'm quite tempted to get one...if they ever come in stock again.

 

[old man mavic]

@scro i can with my hand on my heart tell you ,that in terms of the sound that this drone makes,that it is so totally different ,to any drone i have heard before ,the first time i took it up at the front of my home i was completely gob smacked ,at how the pitch of the sound was compared to my MM ,i have attributed this to the design of the drone, the larger props ,that in turn spin slower for a given amount of lift ,and the way that when you have it low, so you can see the prop tips tracks in relation to each other how close they actually are,that this enables the counter rotation of the props tips ,as they pass each other to somehow cancel out the tip vortices ,which is where the majority of the disturbed air is that determines the pitch of the props,when i flew it 4ft from my friends MM at the same height the MM completely cancelled out the sound from the Mini 3 and everyone of my fellow flyers who have been with me flying have said how quiet it is as well so its not just me

 

[scro]

Thanks for that feedback @old man mavic ! If thwt wasnt enought to convice me completely, I also just found a YouTube video that compared the mini3 to a mini2 and.. a tello! It was even quieter than the tello, and a much easier-to-listen-to tone! I've got a tello, and I must say that I was surprised at that result! Definitely need to lodge a spending request with the resident CFO... and hope some more stock appears soon!

Edit: here's thr link to that vid-

 

[old man mavic]

hope you do get one eventually ,it is a definite step up the Mini drone evolutionary ladder

 

[Zbip57]

I've stored my drone exclusively in the much maligned flymore case and never had an issue with deformed props.

Scratches, chips, and cracks in the propeller blades are easily detected. And if any of those things are present, it's certainly a good idea to change the blades, as a prop failure in flight is really bad news.

Deformed blades however are not nearly as easy to spot. When you say you've never had an issue, it doesn't neccessarily mean the blades were not deformed. It could mean they only weren't yet deformed enough to trigger any warnings or obvious issues.

It would have been interesting to see a graphical plot of your motor speeds in a hover test, before and after replacing your propeller blades. That's really still the only way to know for certain whether there was any significant deformation or not.

It's not merely whether the blades are visibly bent drooping down. The issue is whether the tips have twisted flattening their pitch angle as that has a much bigger effect on the blades performance.

 

[scro]

I watched with close interest a few years back as the whole uncommanded descent saga took shape, and the eventual causes of it identified. I'm quite aware of what causes it and how even seemingly fine props can actually be close to failure in this way. While I don't have some scientific before/after hover tests to scrutinise you did inspire me to dig out a few before/after logs to see if there were any trends. Factoring in what the drone, controller and wind was doing, I was not able to pick out any speeding motors. Granted, a proper hover test would have made this a bit easier and it's been a bit breezy since I swapped the props so I'm not using good solid data to go on.

I did inspect the shape of the blades quite closely and compared the old ones to new ones. One set from the rear drooped slightly further down than the others but the pitch along the length of both new and old was basically identical. By pressing lightly on the wide part of the blade while securing the hub I was able to get the tip to twist into negative pitch. Very easy to see how squashing the blades could dramatically reduce their effectiveness.

With the old props I was reliably able to achieve more than 4m/s vertical speed whilst moving forwards (I may be using slightly non standard parameters ). That in its self is a good indicator that the props were still in healthy shape.

 

[Zbip57]

[...] That in its self is a good indicator that the props were still in healthy shape.

One certainly doesn't hear about these issues nearly as often any more. I wonder what has changed. Maybe less people fly a Mini? Everyone switched to Mini-2 and Mini-3?

 

[scro]

One certainly doesn't hear about these issues nearly as often any more. I wonder what has changed. Maybe less people fly a Mini? Everyone switched to Mini-2 and Mini-3?

I guess it's a mix of people understanding the problem better, migrating towards newer drones, and genuinely incompetents crashing/having a flyaway/giving up flying.

Not meaning any disrespect to competent people crashing or having a flyaway though. I've crashed mine!

 

[scro]

Change in pitch by squashing blade...

I've clamped the hub of the prop onto the desk with one finger, and then pressed down on the highest bit of the leading edge of the blade and the change in pitch at the tip is quite noticable

 

[Zbip57]

I've clamped the hub of the prop onto the desk with one finger, and then pressed down on the highest bit of the leading edge of the blade and the change in pitch at the tip is quite noticeable.

That's a very clear illustration. Thanks for that.

 

[Carsco]

Hello.
Can I ask the distance between the two holes in Mini/Mini2 motors?

I mean this (are 10mm?):

 

[bmcelya]

Anyone else still flying their mavic mini on its original props?

I have a mini2, but maybe this applies. After 218 hours, the original props still function well. As good as new? I dunno. Seems like it. I never liked tip curving via the stock prop holder, so I got aftermarket. One holder for each propeller set. This allows them to stay flat during transport. It only takes a few seconds more to install them. Some have noted that going this route causes trouble putting drone back in the factory case. I use an after market hard case without issue. I assume all this applies to the Mini1 as well.

I carry two DJI replacement prop sets, screwdrivers, and loctite in the travel case. Loctite double bagged in case of leakage. Blue loctite. One of these days Im going to whack something and break a prop. Hopefully I can keep flying with spares, though the loctite wouldn‘t be cured same day. I check props and screws between batteries. Maybe I should retire the original props after this many hours. Anyone with thoughts on service life?

Amazon- Skyreat - Mini prop holders - flexi silicone
Other brands available

 

[Zbip57]

Hello.
Can I ask the distance between the two holes in Mini/Mini2 motors?
I mean this (are 10mm?):

Yes. On my Mini-1, the distance between the prop mounting screw hole centres is 10mm.

 

[Carsco]

Yes. On my Mini-1, the distance between the prop mounting screw hole centres is 10mm.

I thank you so much.