nOxxxx Posted at 3-14 03:21
50 EURO for one arm with a mini 2 engine is too much for me. The revolutions of these engines exceed 20,000 per minute, their service life is about 100 hours of flight in my case, which I made in 10 months during flights over a distance of 3,500 km. These bearings are really cheap and weak. The rear ones will drop faster than the front ones, so I am looking for an answer to why the rear engines have a slightly different design.

Ok good luck with that.

hallmark007 Posted at 3-14 03:07
Motors are extremely cheap, if you want to change one check eBay a lot easier than stripping one down . The refurbish is as new and many times will be equal and better than the drone its replacing. Its very rare these motors will need replacing. Other option for you if you are interested in stripping your drone is look for a crashed one .

Trying to repair things instead of an easy and (relatively) inexpensive exchange might appear a bit stingy. I also prefer a simple exchange, although I hold a HAM licence, so I know a bit about electronics and have some soldering skills.
But it's just interesting if and how things could be done - and in this times, we don't know what next week will look like. Maybe we can be happy to have a small, unobtrusive "spotter" which we want to keep in good shape if regular sales channels aren't available anymore.
Better to know how and not need to know than need to know and don't know how.

Labroides Posted at 3-14 02:46
Just yesterday and further up this thread I politely asked you to read before you write, several times. How about eventually giving that a try?
... you still didn't understand because you still didn't read?

Labroides ... I'll provide you with one last reply: People wish to read about DJI products, not about a guy from Germany showing an Australian the ropes.
As I mentioned earlier, I am a perception psychologist. In this respect, I wish to give you a chance for self-reflection, so your future life doesn't get dominated by disputes but by happiness.

Look at the evolution of your posts. You started with not reading and not understanding. But instead of saying "Oh, sorry, got that wrong." and keeping quiet or participating in a constructive way, you chose to head the way of denial. You got polished off, then grabbed the next chance for rude remarks. You got polished off again big time. And now you had to revert to offending gutter language because there's no way of getting out of embarrassment with your head held high.
Isn't that frustrating?
I saw you attacking others in offensive ways prior to my registration, so I knew you in advance.
I could have chosen to simply ignore you - or to show you the red line. I went for the latter, you got your lesson.
Now use that experience to your advantage. Try to be more open and friendly, find friends, learn to admit a mistake. You'll see that your life will change.
German saying: "Wie man in den Wald hineinruft, so schallt es heraus." If you're into the Bible, read Galatians 6, verse 7: 'A man reaps what he sows.'
It's true.

Please refrain from launching the next volley of swear words, you know it will turn into a boomerang.

nOxxxx Posted at 3-14 02:49
When I started this thread I had an issue with the noticed noise of the bearings on both rear motors. At one point the noise became a nuisance, it seemed to me that tightening the screws of the engine structure from below brought an improvement, but it was only an illusion. I sent the drone to the service DJI and got the drone in return, possibly a refurbisch. Now there is a big improvement. I have assessed the chances of replacing the bearings myself, but there are some difficulties. The rotor shaft is glued in and the ball bearing is secured with the crimped edge of the housing. There are two bearings, one plain at the bottom and one ball bearing at the top. The bottom is not sealed, but a sponge pad provides some protection. The upper bearing is type ZZ. Most likely in the size of 2x5x2.5 mm. I will want to verify it in order to replace it myself later. And also a curiosity. The refurbished drone had a slightly skewed rotor. Today I also want to measure the curvature with a dial gauge.

Ah, nOxxx!
That's what I call a name!  

Good to see there's people getting to the bottom of things.
So it was noise getting you on track? Noise is often a quite good indicator. Just a few days ago, my Mini 2 returned home - and something sounded different, I could not tell exactly, but there was a difference. I closely inspected the propellers - and indeed, a tiny fraction of one propeller's tip was missing. I didn't see the defect, I heard it. Similar with spent cartridge cases - if there's 100 in a box with just one defective case, you will indeed hear it.
Replacing the bearings doesn't seem to be an easy task, if feasible at all.

Ah, I now see you're from Poland, a "neighbor".
That deepens my trust in your mechanical skills - a Pole (or a Thai) can repair just everything!

Landey Posted at 3-14 05:36
Trying to repair things instead of an easy and (relatively) inexpensive exchange might appear a bit stingy. I also prefer a simple exchange, although I hold a HAM licence, so I know a bit about electronics and have some soldering skills.
But it's just interesting if and how things could be done - and in this times, we don't know what next week will look like. Maybe we can be happy to have a small, unobtrusive "spotter" which we want to keep in good shape if regular sales channels aren't available anymore.
Better to know how and not need to know than need to know and don't know how.

Yes I’m passed repairing things now, but times are certainly different . We used to buy things and expect them to last forever, now we just throw them out, going back a bit might not be too bad if we all could slow down just a little. ;+)

Landey Posted at 3-14 06:05
Labroides ... I'll provide you with one last reply: People wish to read about DJI products, not about a guy from Germany showing an Australian the ropes.
As I mentioned earlier, I am a perception psychologist. In this respect, I wish to give you a chance for self-reflection, so your future life doesn't get dominated by disputes but by happiness.

I am a perception psychologist. In this respect, I wish to give you a chance for self-reflection, so your future life doesn't get dominated by disputes but by happiness.
I'll give you a chance for self reflection
It seems that you are the one that has difficulty with comprehension.
I'll give you a chance for self reflection
You are a stupid tosser.
Go away.

AerialZup Posted at 3-14 13:53
I just want to point out:
All the motors are the same. The rear ones do not have any different design. DJI can verify that for you as well.  They are identical. Germans do make the best gummy bears, btw.

Hi there! ;)

Let's wait for nOxxxx making sure. I would also believe the motors are identical - would be a logical decision in the light of business: Identical motors bear some benefits like easier stockkeeping, no mismatches and better purchase prices because of higher volume.
But still, they feel different. And using slightly more powerful ones to compensate the higher weight of the rear would also make sense. So I am really curious about the outcome.

About the gummy bears: You have no idea what German laws did to them.
I remember my childhood, I loved gummy bears like every child is supposed to. Especially, I loved the green ones, tasting of woodruff. But one sinister day, the world changed - green ones turned into light green ones; and didn't taste of woodruff anymore. I had to read the package info to find out they now tasted of strawberries, which they didn't. I felt devastated. HOW COULD YOU, Haribo?
Later, I found the reason: Woodruff contains cumarin, a substance hindering blood coagulation. A highly clever guy estimated that after eating several kilograms of green gummy bears at once, your blood coagulation would be severely affected, so you could die of blood loss if you accidentally cut off a leg or your head. This utmost likely circumstances immediately triggered the single neuron left in the German government, labelled with "verboten", so they stopped use of real woodruff in food products.
And that's how they killed my dearest bear, the genuine green gummy bear.
Now let's hold a minute's silence before we turn to other topics again.

Landey Posted at 3-15 00:12
Hi there! ;)

Let's wait for nOxxxx making sure. I would also believe the motors are identical - would be a logical decision in the light of business: Identical motors bear some benefits like easier stockkeeping, no mismatches and better purchase prices because of higher volume.

If you put more powerful motors on one side of the drone all motors will be reduced to the least powerful motor. So yes you can have 4 different motors on the drone but I’m afraid it won’t help. Increasing speed of rear motors will be enough to compensate for weight , or decreasing speed of the front motors. I’m sure if you had more flight controllers 3 at least different ESCs different wiring and a much bigger drone it might be possible but not practical.

Maybe a gummy bear stuck in the rear motors ;+)

The mystery has been solved. I did all the possible tests, namely I measured the dimensions of the front and rear engines exactly and they were identical. Magnetic gaps, although there is a certain discrepancy, most clearly it is caused by the production tolerance. I measured the magnetic flux with a magnet tester. There are no differences here either. So those who said that the engines were identical were right. Unfortunately, they were unable to pinpoint the reasons why there is a significant resistance to manually turning the front and rear engines. So where is the reason for this? In a closed circuit of the rear motors through the transistors on the ESC. When the wires are disconnected from the ESC, the rear engines begin to turn with a resistance identical to the front engines.

nOxxxx Posted at 3-15 12:15
The mystery has been solved. I did all the possible tests, namely I measured the dimensions of the front and rear engines exactly and they were identical. Magnetic gaps, although there is a certain discrepancy, most clearly it is caused by the production tolerance. I measured the magnetic flux with a magnet tester. There are no differences here either. So those who said that the engines were identical were right. Unfortunately, they were unable to pinpoint the reasons why there is a significant resistance to manually turning the front and rear engines. So where is the reason for this? In a closed circuit of the rear motors through the transistors on the ESC. When the wires are disconnected from the ESC, the rear engines begin to turn with a resistance identical to the front engines.

Good job.  I’m not sure all Mini2 would be the same so it may not be that all have a similar resistance on the rear. Thank you for the information it is very helpful and I’m  not sure many would have discovered or tried to discovered the reason behind this.

As for the motors they:

1/ where exactly the same
2/ they would be of the same power
3/ that there would be no point in putting more powerful motors on the drone
4/ backward forward left and right speed is identical
5/ and we are all a little wiser now ;+)

I wonder when the apologies will start?

nOxxxx Posted at 3-14 03:00
Don't worry about what Labroides writes. He's an old, decrepit troll. He always spoils the discussion and gets unhealthy satisfaction from it. My advice is to just spray him with warm urine.

Decrepit troll?
Giving correct information spoils discussion ??

Landey Posted at 3-14 06:05
Labroides ... I'll provide you with one last reply: People wish to read about DJI products, not about a guy from Germany showing an Australian the ropes.
As I mentioned earlier, I am a perception psychologist. In this respect, I wish to give you a chance for self-reflection, so your future life doesn't get dominated by disputes but by happiness.

Labroides ... I'll provide you with one last reply: People wish to read about DJI products, not about a guy from Germany showing an Australian the ropes.
As I mentioned earlier, I am a perception psychologist. In this respect, I wish to give you a chance for self-reflection, so your future life doesn't get dominated by disputes but by happiness.
Thanks so much for "showing me the ropes"

Look at the evolution of your posts. You started with not reading and not understanding.
That didn't age well did it?

But instead of saying "Oh, sorry, got that wrong." and keeping quiet or participating in a constructive way, you chose to head the way of denial. You got polished off, then grabbed the next chance for rude remarks. You got polished off again big time. And now you had to revert to offending gutter language because there's no way of getting out of embarrassment with your head held high.
Who got it wrong?   Who was polished off and polished off again??

I saw you attacking others in offensive ways prior to my registration, so I knew you in advance.
Your research was sloppy.
You failed to notice that I know drones and give a lot of good advice.

I could have chosen to simply ignore you - or to show you the red line. I went for the latter, you got your lesson.
Is that the lesson about what a smug little weasel you are?
Perceptual psychologist !!!  Hah!

Now use that experience to your advantage. Try to be more open and friendly, find friends, learn to admit a mistake. You'll see that your life will change.
How's your self-reflection going?

I looked up Perceptual psychologist and it said "See: wanker"

nOxxxx Posted at 3-15 12:15
The mystery has been solved. I did all the possible tests, namely I measured the dimensions of the front and rear engines exactly and they were identical. Magnetic gaps, although there is a certain discrepancy, most clearly it is caused by the production tolerance. I measured the magnetic flux with a magnet tester. There are no differences here either. So those who said that the engines were identical were right. Unfortunately, they were unable to pinpoint the reasons why there is a significant resistance to manually turning the front and rear engines. So where is the reason for this? In a closed circuit of the rear motors through the transistors on the ESC. When the wires are disconnected from the ESC, the rear engines begin to turn with a resistance identical to the front engines.

Ah, that explains it! ;)
Thank you very much for digging that deep into the guts of the Mini.

@hallmark007: I guess (but of course can't know for sure) that all Mini 2 motors show a different feel of resistance between front and rear motors, not primarily caused by manufacturing tolerances, but by circuit design.
We all know that effect if we ever rode a bicycle with lights powered by a dynamo. If the light was on, we had to work the pedals with more power than with the lights switched off. It's a similar effect with our motors, causing the different feel.

But it's good news: If we wish to exchange the motors, one type will serve front and rear.

Labroides Posted at 3-15 14:25
I wonder when the apologies will start?

Labroides ...
Of course you deserve an apology - and my recognition in addition, complemented by a hint: "Better don't read on."

To refresh your memory: We talked about a different rotational resistance of front and rear motors, not about any malfunctions, problems or issues. You didn't get that. I explained to you multiple times there is no issue, just curiosity about the reasons. You didn't get that. I asked you to read. You claimed to have read, but you still didn't get. I asked you to read again. You again claimed to have read, but just as before you didn't get it. Now I made a mistake: I asked you to read and understand. You responded with swear words.
My mistake: I presumed you would be able to understand, like any other adult would. I was wrong. Thus I need to honestly apologize for overestimating your mental capabilities.

Now for the recognition: I recognize your effort of making yourself heard, of aggrandizing yourself by using a lot of stimulating terms like "twat", "tosser", "wanker" and so on to catch my and my forum fellows' attention instead of boring us with facts regarding the topic.
You also introduced an alter ego (just google the meaning), accidentally-on-purpose also from Australia, freshly registered, astonishingly using the same kind of attention-inducing terms.
That's what I call an effort.
And that's why you honestly deserve my recognition.

Three  hints at no cost:
1) Don't take the walls of railstation restrooms for dictionaries.
2) Albert Einstein: "The definition of insanity is doing the same thing over and over and expecting different results."
3) Read the Bible if you wish to understand my way of communicating with you. Start with: Proverbs 26:5 - "Answer a fool according to his folly, lest he be wise in his own eyes."

Have a nice day.

Landey Posted at 3-17 01:29
Labroides ...
Of course you deserve an apology - and my recognition in addition, complemented by a hint: "Better don't read on."

That's not an apology ... You just don't give up, do you?
I gave accurate information right from the start, but you couldn't help yourself with the offensive and condescending garbage you kept dishing out.

You also introduced an alter ego (just google the meaning), accidentally-on-purpose also from Australia, freshly registered, astonishingly using the same kind of attention-inducing terms.
Geebax, who you describe as my "alter ego (which I don't have to look up),  lives about 200 km from where I do.
It's not particularly astonishing that he uses similar terms to describe someone who's proved to be a total tosser.
That's how many Australians talk, especially when we have to deal with "perceptual psychologists".

Labroides Posted at 3-17 02:29
That's not an apology ... You just don't give up, do you?
I gave accurate information right from the start, but you couldn't help yourself with the offensive and condescending garbage you kept dishing out.

Labroides ...

Quote: "That's not an apology ... You just don't give up, do you?"
Didn't I apologize? I did, so honestly. So whats makes you think, sorry, believe it isn't?
About giving up: You asked me not to contact you again, which I did. It was you seeking my attention again. Just scroll up and read.
As I am a friendly and polite person, I answer questions if someone asks for feeding his thirst for knowledge.

Quote: "I gave accurate information right from the start, but you couldn't help yourself with the offensive and condescending garbage you kept dishing out."
Let me correct you: "condescending" is a proper term as it nicely defines our two distinct positions. But garbage? How about providing a few examples of me telling garbage? Last time I asked you for examples, you reverted to swear words. I guess this will turn out as a kind of tradition.

Quote: "Geebax, who you describe as my "alter ego (which I don't have to look up),  lives about 200 km from where I do."
I asked you to read and understand, remember? You should have looked up the term "alter ego". I choose my words wisely (just google this term).

Quote: "It's not particularly astonishing that he uses similar terms to describe someone who's proved to be a total tosser."
So it's proved. If something is proved, you'll surely be able to provide proof. By the way: Swear words are not regarded as proof. So go ahead, I am listening.

Quote: "That's how many Australians talk, especially when we have to deal with "perceptual psychologists"."
Remember I asked you to read? Again, you didn't or it's the lack of understanding again. Just show me where I wrote "perceptual psychologist".


In return, let me show you something:

Landey Posted at 3-17 02:55
Labroides ...

Quote: "That's not an apology ... You just don't give up, do you?"

You are possibly the most offensive little prick I've ever encountered in this forum

And all this is because I answered the questions asked, way back in this sorry thread.
That should have been enough for almost anyone.
But not you.
In your ignorance of drones, you were still sure that you knew more than me.
You refused to believe that my answer could have been correct, even when I gave detailed explanation to support it and just kept dismissing my information.
And to top it off, you had to preface almost each reply with your smug .. "you didn't read what I wrote" nonsense.

I hope you lose your drone some day and come looking for help.
I'd be able to demonstrate my data analysis skills to help find where the drone ended up.
Except for you, I wouldn't.

Labroides ...

We could happily continue talking about the difference of "I wouldn't" and "I couldn't", about the use of swear words for compensating lack of suitable and telling arguments, also about you not being able to provide proof of "proven" things, exactly as expected.
But as you seem to be quite close to bursting into tears, I suggest we suspend our utmost fruitful communication for now. Which means I won't respond to you for quite some time.
Ah, one last thing ... I seems like you didn't read the Einstein quote, which possibly had helped you understand your own position, and not the Bible quote, which possibly had helped you understand my position. Just read. ;)

Landey Posted at 3-17 03:43
Labroides ...

We could happily continue talking about the difference of "I wouldn't" and "I couldn't", about the use of swear words for compensating lack of suitable and telling arguments, also about you not being able to provide proof of "proven" things, exactly as expected.

There's just no off setting on your ignorant/arrogant switch.
Get lost, you stupid sanctimonious wanker.

All this talk about motors and no one has completed the story by saying...should a motor go bad...for any reason, does DJI sell an arm and motor for replacement (at a cost) here in the USA. I saw these replacement parts on Amazon, but they are all from different companies in China and not certified DJI. I was about to buy the product from B&H, out of New York City, but they also do not have DJI replacement parts for the arm and motor...or just the motor. That's not good customer service, since it's just a matter of time before the motor goes bad (for whatever reason) being that is the ONLY mechanical device on the drone. I hesitate to purchase it because of this important fact.
So...that being said...someone please help me in understanding WHY DJI does not sell this important part. Of all the products out there in the world, great companies ALWAYS tries to satisfy the buyer. That is what good company's do. I have been in photographer for a long time and not once did CANON ever put their customers in a dilemma buy not helping them in some way. I will call DJI today and find out why these motors are not on their list of things to purchase, should a motor become bad. I will reply back and let everyone know why this is.

With respect,

Patrick Cambre

P.S. If you would like to call me on the phone and discuss this, my phone number is 337-385-7589 here in the USA. I would really like to purchase the Mini 3, should I not be thinking of something that someone else may offer me.