Propeller Storage Solution

[issDaemon]

I tried a could of different options for holding the propellers in a safe position in the Fly More Combo case, and didn't really like any of them. There was a small silicon band on a cable I had received recently, and it looked perfect for the task, so I set out to find some more, and lo and behold, I found these on Amazon: Amazon.com: ONLYKXY 200 Pieces Silicone Cable Ties, Data Lines Silicone Cord Ties, Reusable Rubber Rings, Power Cable Tie Straps, Elasticity Coil Ring, Rubber bands: Home Improvement. They provide the perfect amount of retention, and do not compress the props too much. Getting them on is a little fiddly, but no worse than the other things I tried. These really are the perfect solution for me!



As a bonus, you can also use these to corral your USB cables, and probably a dozen other things.



It's like a 200 pack of mini Ranger bands!

 

[Dronason]

I think you should have a look to that thread MOTOR SPEED ERROR MAVIC MINI that discuss the new issue about storing MM and its effect on propellers.

 

[issDaemon]

I think you should have a look to that thread MOTOR SPEED ERROR MAVIC MINI that discuss the new issue about storing MM and its effect on propellers.

I read that, and as far as I could tell, it offered nothing definitive.

 

[ATP]

I use a small rubber band by hooking it over thr motor, stretch it over the second motor with a twist in the middle. Works for both front and rear and fits in Flymore case, cheap too.

 

[Occams Razor]

For me, the jury still is out on whether that’s a safe approach for storing the Mini. On the other hand, I really like those silicon bands and will buy a set for general use. Thanks for sharing.

 

[Slade]

I use a small rubber band by hooking it over thr motor, stretch it over the second motor with a twist in the middle. Works for both front and rear and fits in Flymore case, cheap too.

Rubber Bands always work???

 

[scro]

How do you put the bands on the props?! Fitting them looks like harder and fiddlier work than just trying to get the blades to sit in the right recesses in the flymore case!

 

[issDaemon]

For me, the jury still is out on whether that’s a safe approach for storing the Mini. On the other hand, I really like those silicon bands and will buy a set for general use. Thanks for sharing.

No problem! The fit is very similar to the paper bands that come on the props from the factory, so I am going to go with it for now, being very careful to align them as they were from the factory. I'll report back if I start seeing issues.

 

[issDaemon]

How do you put the bands on the props?! Fitting them looks like harder and fiddlier work than just trying to get the blades to sit in the right recesses in the flymore case!

Slide the band as far onto the lower set of props as you can



Angle the blades to get the tip of the other pair in the band



Close the props as you would normally and slide the band to the middle



Not all that difficult really.

 

[scro]

Not as fiddly as I though, but still fiddlier than not putting them on ?

I don't find the front props to be an issue at for getting stowed properly in the fly more case. Just align them so they are directly above the arms and the pad in the lid of the case drops down between the blades when the case is closed. The rear props are fiddlier to stow, and that's where most of the deformed props issues arise. My technique is to rest the 4x tips together directly under the camera unit and lower the drone into the case carefully. Stowing the blades folded across each other can result in the inner pair of blades getting slightly bent. The 2 rear motor axes are not parallel (the motors are canted outwards slightly to aid with yaw movements) so the 2 pairs of blades also aren't parallel to each other and don't interleave with each other so well. There are some reports on this forum of people having to replace the rear blades on pretty much new drones, possibly due to them getting deformed when folded right across in the factory.

Anyway.. if the little silicone bands work for you then keep using them ? They certainly look tidy.

 

[Zbip57]

I read that, and as far as I could tell, it offered nothing definitive.

Have you looked at these two specific posts in that thread?
mavicpilots.com/threads/motor-speed-error-mavic-mini.86130/page-13#post-1038101
mavicpilots.com/threads/motor-speed-error-mavic-mini.86130/page-13#post-1038918

It's a theory, which like you said is not definitive. But I'm really curious why you're not convinced?

I get it that the rubber bands keep the prop blades from flopping around to ensure they always sit "properly" in the trough of the Fly More case. But I'm convinced that's not the problem.

How long have you been storing your props like that? Have you ever received the Motor Speed Error warning message? If your rear props slide easily together to nest over/under each other when folded, then they're probably already bent. A fresh set of brand new rear props do not fit together like that unless forced to bend under each other.

Have you ever done the hover test to check their performance?

There's no pressure at all. I'm just curious.

It's dead simple. Press auto-takeoff, allow it to hover for a couple of minutes, then press auto-land, all without touching the control sticks, preferably indoors to eliminate any wind influence. Then plot motor speeds.

If you don't know how to access the flight log DAT file, or plot the motor speeds, I'd be happy to help. Or you could just post the DAT file here for us to plot the motor speeds for you.

The reason I ask is I'm fully convinced the prop deformation issue has nothing to do with incorrect storage, although that certainly wouldn't help. I believe even "proper" storage results in prop deformation whenever the rear props are crossed over each other.

The deformation might only be very subtle and unlikely to be detected by a quick visual inspection. The hover test, however, is a definitive measure of motor speeds and prop efficiency.

If you're game to try it, yours would be a really good test case.

 

[Zbip57]

For example, here is a set of fresh blades mounted on both my rear motors. You can see how the tips cross. Blade #1 is still straight, whereas blade #2 is being forced to bend down to nest under the opposite blades.

 

[SkyeHigh]

Why not just use a thin strip of Velcro? Quick and easy to attach and remove and no pressure on the blades. And... a choice of colours!!

 

[Hill Top Rez]

I purchase a new case from Amazon which I love as it gives me more space and does not have the cross piece as in the flymore case. It is a high quality case with nice storage capacity. I no longer use the flymore case at all.

 

[raulmavic]

Your silicon band for holding the propellers in a safe position is a good commercial option, but I recommend you trying my DIY ribbon and velcro propeller holder

It's working great for me. No motor speed warnings anymore !

Best regards

R.

 

[issDaemon]

Have you looked at these two specific posts in that thread?
mavicpilots.com/threads/motor-speed-error-mavic-mini.86130/page-13#post-1038101
mavicpilots.com/threads/motor-speed-error-mavic-mini.86130/page-13#post-1038918

It's a theory, which like you said is not definitive. But I'm really curious why you're not convinced?

I get it that the rubber bands keep the prop blades from flopping around to ensure they always sit "properly" in the trough of the Fly More case. But I'm convinced that's not the problem.

How long have you been storing your props like that? Have you ever received the Motor Speed Error warning message? If your rear props slide easily together to nest over/under each other when folded, then they're probably already bent. A fresh set of brand new rear props do not fit together like that unless forced to bend under each other.

Have you ever done the hover test to check their performance?

There's no pressure at all. I'm just curious.

It's dead simple. Press auto-takeoff, allow it to hover for a couple of minutes, then press auto-land, all without touching the control sticks, preferably indoors to eliminate any wind influence. Then plot motor speeds.

If you don't know how to access the flight log DAT file, or plot the motor speeds, I'd be happy to help. Or you could just post the DAT file here for us to plot the motor speeds for you.

The reason I ask is I'm fully convinced the prop deformation issue has nothing to do with incorrect storage, although that certainly wouldn't help. I believe even "proper" storage results in prop deformation whenever the rear props are crossed over each other.

The deformation might only be very subtle and unlikely to be detected by a quick visual inspection. The hover test, however, is a definitive measure of motor speeds and prop efficiency.

If you're game to try it, yours would be a really good test case.

Your posts are very thorough, and I appreciate your input on this issue. I haven't seen the motor speed warnings, and I have stored mine exactly as it came from the factory with rear blades crossed since new, and you're correct, I can't visually identify any issues. I have not done the hover test, specifically, but I have hovered for at least 2 minutes, albeit at 300 ft while I captured a sunset. I'll give the indoor hover test a shot and grab the DAT, as I have DJI Assistant, then I'll report back here.

 

[issDaemon]

Why not just use a thin strip of Velcro? Quick and easy to attach and remove and no pressure on the blades. And... a choice of colours!!

Velcro might be an option if I find these silicone bands don't work, or cause motor speed issues, which I am starting to suspect is a likely outcome.

 

[issDaemon]

Your silicon band for holding the propellers in a safe position is a good commercial option, but I recommend you trying my DIY ribbon and velcro propeller holder

It's working great for me. No motor speed warnings anymore !

Best regards

R.

Thanks! I might give this a shot if the bands don't work.

 

[issDaemon]

Your posts are very thorough, and I appreciate your input on this issue. I haven't seen the motor speed warnings, and I have stored mine exactly as it came from the factory with rear blades crossed since new, and you're correct, I can't visually identify any issues. I have not done the hover test, specifically, but I have hovered for at least 2 minutes, albeit at 300 ft while I captured a sunset. I'll give the indoor hover test a shot and grab the DAT, as I have DJI Assistant, then I'll report back here.

I did the hover test and got the mobile data file for my flight (not the DJI Assistant DAT export) and loaded it into CsvView, and here is the motor speed graph.



Looks like maybe the left FRONT is spinning a little faster than the rest, but not the left rear.

 

[Zbip57]

I did the hover test [...] and here is the motor speed graph.
Looks like maybe the left FRONT is spinning a little faster than the rest, but not the left rear.

Hey, thanks for doing that! Those are very interesting results.

On my Mini with new props installed the motors all average about 9600 rpm at hover. That looks to be the same for three of your motors, with only the left FRONT spinning about 1000 rpm quicker.

Just one more question. Did you do your hover test indoors or outdoors?

It makes my wife nervous when I fly my drones inside, so when I did another quick hover test the other day I decided to do it outside while the wind was almost dead calm. The result surprised me and caused some consternation. Suddenly the left-rear was back to spinning faster than the other motors! Huh? Why??


I haven't put the Mini back into its Fly More case or folded the props together. What's going on? So I did another test inside and, presto, the motors are all back to spinning at the same speed. Phew.

I think the difference was due to the light breeze that was blowing outside, causing the left-rear to work just that little bit harder to hold position against the breeze. Even on this indoor test (below), it took about 25 seconds for the Mini to stabilize in a level hover.


I think your 1000 rpm difference is not critical. But if you ever eventually do receive the Motor Speed Error warning, the hover test is a good way to determine for yourself whether the motor identified by the beeping ESC actually is misbehaving. Certainly any motor hitting 16,000 rpm is cause for concern.

Dismissing the Motor Speed Error warning offhand as a defective firmware glitch is foolhardy. Check your motor speeds with a hover test and you'll know for sure whether there's anything to worry about.