Propeller Storage Solution

[scro]

If doing a hover test outside try doing it at least twice, with the drone pointing in opposite directions for each test. Better still, do 4 tests and spin 90deg between each. That way you can see the effect any breeze is having.

 

[eaglesurfing]

It does not take that long to take them off and put them back on. If I am packing then that is going to happen.

 

[Zbip57]

If doing a hover test outside try doing it at least twice, with the drone pointing in opposite directions for each test. Better still, do 4 tests and spin 90deg between each. That way you can see the effect any breeze is having.

That makes sense. If I ever do it outside again, I'll certainly do that.

I didn't think to try that, rotating it into different directions to see the effect of the breeze, because I didn't think there even was a breeze. I just did a quick hover test to compare the difference between with/without prop guards installed. It was only later when plotting the motor speeds that I saw the left-rear motor spinning faster again. i almost cried, because that didn't make any sense to me at all.

It was two days later when I decided to repeat the test indoors and, tada, it's back to normal. Phew. So the elevated speed on that one motor had to have been due to just that slight breeze outside.

 

[Zbip57]

It does not take that long to take them [the props] off and put them back on. If I am packing then that is going to happen.

I'd be more worried about the prop mounting screws holding properly after the blue loctite has been disturbed.

 

[issDaemon]

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??
View attachment 106542

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.
View attachment 106543

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.

My test was indoors, it was actually the second of two, because the quad was constantly adjusting. It was kind of a small area where I did the test, and I think the prop wash may have been affecting the quad similar to a wind, because it was jerking around quite a bit. I may do the test in a bigger area like my garage, to rule that out, or even outdoors in perfectly still conditions.

I think this was a very worthwhile exercise, if for nothing else than to learn how to retrieve and analyze flight data. Thanks for all the pointers! I'll certainly be keeping an eye on it, and now I know how to go a little deeper with the troubleshooting.

 

[Zbip57]

I think the prop wash may have been affecting the quad similar to a wind, because it was jerking around quite a bit. I may do the test in a bigger area like my garage, to rule that out, or even outdoors in perfectly still conditions.

For sure. Try to minimize as much as possible any external influences that only complicate the results.

I think this was a very worthwhile exercise, if for nothing else than to learn how to retrieve and analyze flight data. Thanks for all the pointers! I'll certainly be keeping an eye on it, and now I know how to go a little deeper with the troubleshooting.

Excellent! I wish more people would see the value of conducting their own experiments, rather than relying on the questionable and often conflicting advice of so many uninformed users. I could very well be completely mistaken in my theory. I'll be more than happy to admit that, if someone has a better theory with actual factual evidence to prove what's truly going on.

It drives me crazy that so many people immediately assume the firmware is faulty, or that the firmware upgrade failed somehow, and that there's nothing at all wrong with the propeller blades despite the Motor Speed Error warning telling us to replace the props.

 

[bobc2]

propeller holder — almost free and readily available: sections of “PostIt” sticky notes

 

[issDaemon]

After looking at this a little deeper, mostly due to the points that Zbip57 makes on this thread, and in the excellent post here, I have decided not to store my Mini in the Fly More case. While I have not gotten the motor speed error, I did notice that the left rear props are "flattening out", most likely due to the stress that is placed on them by the angle of the rear motors while being stored in the case. I will still use the case and the bands when transporting the Mini, but I will arrange the propellers as shown in the images below.



Arranging the rear propellers like this puts no strain on either side, and still easily fits in the case. There was very little strain on the front props with them folded together, but there's plenty of room in the case, and arranging them pointing straight down the arms neither interferes with the case, nor puts any strain on them. The bands keep the props from moving nearly as much, does not flex the props against their design, and makes the Mini much easier to put in the case.

So in short, the bands are still useful for storing the props, just not per the DJI recommendations. YMMV and all that.

 

[22kane]

I use 2 of wife's rubber hair bands. Fits perfect holding the blades in place, and in the combo case.

 

[Rchawks]

I also use paper

 

[raulmavic]

My ribbon & velcro solution:

 

[AMRE2ME2]

I don’t like using any type of rubber band. It can get caught and put too much tension on the props. Use Velcro. Much easier to put on and remove and holds Props without the chance of putting stress on props which is what the whole purpose is.

 

[issDaemon]

I think the whole point is not to fold the rear props like is recommended by DJI, whether you use paper, rubber band or whatever to hold them. It puts too much stress on the left rear props, causing them to eventually "flatten out" and become less efficient, providing less lift, requiring higher RPM to compensate and eventually producing the "MOTOR SPEED ERROR". Otherwise, there seems to be many options (and opinions) on materials used to secure the props when stored. I happen to like the 10mm silicone bands (arranged as in post #28 above) as they put very little pressure on the blades, but just enough to keep them from flopping around and getting pinned under part of the case.

 

[STLBluesNut]

I have had my mini less than a week and this forum has been very helpful. After seeing multiple posts about storing the props folded and the Fly More case I tried to think of a solution. This may have been posted on some other thread at some point but I came up with the idea below.

The shape of the impression in the case made the bottom props fold in no matter what. I figured if I could press those corners in they could extend forward more. That didn't really work so I went to cutting with my exact knife.

With the holes cut out the props can now go in straight or worst case in a v shape under the gimbal cover. They aren't folded and bending anymore though. I could probably trim out even more. With the Mini in there you cannot even tell there are holes cut in it. You could even store extra stuff in there if you wanted to.

 

[issDaemon]

I have had my mini less than a week and this forum has been very helpful. After seeing multiple posts about storing the props folded and the Fly More case I tried to think of a solution. This may have been posted on some other thread at some point but I came up with the idea below.

The shape of the impression in the case made the bottom props fold in no matter what. I figured if I could press those corners in they could extend forward more. That didn't really work so I went to cutting with my exact knife.

With the holes cut out the props can now go in straight or worst case in a v shape under the gimbal cover. They aren't folded and bending anymore though. I could probably trim out even more. With the Mini in there you cannot even tell there are holes cut in it. You could even store extra stuff in there if you wanted to.

I considered this myself, but I don't trust my cutting skills enough. I suppose if you decide you don't like this, you could always just buy a case that can be customized to hold the props in a better arrangement. I would like to make the Fly More case work, but it's clear to me that the DJI recommendations for storing the props are potentially causing damage to some Minis, so I'm not going to bind the props together, or "stack" or "fold" them anymore. Regardless, I do like the "compactness" of the Fly More case because it's easy to throw in a backpack or bag and just go. I think DJI should address this issue with more than just a firmware update, maybe a redesigned case and updated storage recommendations? Otherwise, the Fly More case as is, is pretty useless, and even detrimental.

On a side note, I am working on 3D printed organizers for the Fly More case for beneath the charger and controller. Just tossing all the extras in the cavities beneath is not ideal for me. I'll post them up when I have refined the design enough.

P.S. - I wonder if it would be possible reshape the cavity with a heat gun, foregoing the cutting and what not? Just a thought.

 

[Deleted member 103366]

I thought about doing this but didn't want to cut 'huge' holes in the case, had I done so I think my cutting lines would have been either of those shown in yellow in the attached.
Since you have cut holes can I suggest removing the bits I have circled in red, the reason being those shoulders tend to push the blades inwards, as you found, and they mesh somewhat, once meshed they may not disengage from one another under their own weight.