Hi,
Today i noticed that my mini shakes while take off. It shake as I can see only front left motor. it is only one shake and then hover and fly normaly. This is hapend only if I catch MM with hand and flip him over to shut down propellers. Then on the next take off motor shake. If MM land normaly that is not the case. On the next flight everything is OK. Is this normal behavior? Can anybody try to do this?

Are your propellors intact and free enough to swing on their pivots solely under the influence of gravity?
Are their screws nipped up but dont over tighten, if you strip a thread you could be in difficulties.

I think the catch and twist thing should be regarded as for emergency use only.

If my mini is landed in my hand i.e. flown onto my hand not snatched from the air, the motors will shut down of their own accord, if they don't holding the throttle closed for a second or two will shut them down.

Everything is OK. MM is almost new i never change props or screws. Everything is stock. I dont know why it's only happens if i shut down MM by catch and flip. If MM land normally on next flight everything is good.

Can you answer the questions, are your propellors free enough to swing on their pivots solely under the influence of gravity?
Are their screws nipped up?

I am wondering if something is preventing them from swinging on their pivots and or holding them out of position until the motors are up to speed and the 'centrigfugal force' is enough to throw them outwards into balance with one another.

Yes they are free enough. There is no differences, all motors and props are free. If something prevent spinning props then at all take off will be same problem. But there isn't. It only appears if i land MM by flipping

You should not catch and flip the drone, except it's an emergency. It damages your props and motors for obvious reasons. I spare you the physics lesson. I know all the big youtubers do it. Just don't if you want your mini to last.

Is there, by any chance that the props are not fully extended, and the motor start pulse is what you may be seeing?
That initial "pulse" is to "open the propellers if not already opened by the user...

Vibrations when the motors start spinning are usually caused by a prop being too tight, requiring some more RPMs to fully extend out and move to a balanced, symmetrical position. Since  you ruled that out and there is nothing mechanically wrong with your motors and props, then the only explanation would be for the firmware to remember the AC got flipped, and do something strange at startup the next time, causing a bit of a shake. I don't see why it would do that, but in theory it would be possible.

In any case, like others said, why flip it in the first place??? Even if it takes a second or less, you're causing the flight controller to respond to the flip, giving max power in the attempt to keep the AC level. That puts unusual and totally un-needed stress on the motors, props and arms. Just don't do it.

The attached photo is of the wrong handing but it conveys the message well enough
Are there any bumps on the trailing edges of the affected blades in the area where they make contact with their companion or on the relevant part of the companion blade's hub?
Possible tests,
1) remove the left front blades and check the pivots for damage or contamination, spin the motor by hand, does it feel damaged in any way in comparison to the other motors? Refit the blades and see if the problem has gone?
2) remove all the props, hold the drone in your hand with a finger in contact with the left front arm and run the motors up to say 1/3 full throttle and 'see' if you can feel any unusual vibratioins.
3) reinstall the blades BUT put the ones from the left front motor on the right rear motor and vice versa. RF & LR get their original blades, fly the drone and see if the problem has switched motors.

Hi. I am sorry for the trouble this has caused. With regards to this concern. Kindly please check if there are any deformity or damages on the propellers this may cause the issue. Please keep us posted for further assistance. Thank you.

I am new with drones, I watch on youtube how to land on hand  and flip it over tu shut down. Nobody say that this is bad for motor and drone. Props are fine there are no visual deformations or damages. I could try to change position of the props, but i am wondering about screws. Isn't they for only one time to use?

zip007 Posted at 7-22 00:51
I am new with drones, I watch on youtube how to land on hand  and flip it over tu shut down. Nobody say that this is bad for motor and drone. Props are fine there are no visual deformations or damages. I could try to change position of the props, but i am wondering about screws. Isn't they for only one time to use?

And is everything you see on youtube correct?

You have several poster here saying that, as a routine method of stopping the motors, catch and twist is not a good idea. That I am aware of DJI do not mention it with whatever impication you wish to draw from that.

It comes down to who you think offers more credible advise. Whilst some you tube posters do do some VERY GOOD stuff there are others that I think are just doing stuff to look 'cool'and some post complete tripe.

Re catch and twist, take a bicycle wheel, hold it so the axle is horizontal, spin the wheel up and then try to twist it suddenly so that the axle is vertical. You are asking the bearings of the motors to do the same thing to the motor rotors and the props.

With regards to the screws, yes you are correct in that they are suppposedly one time use only but unless you are prepared to change the props for new ones what other options do you have. If you are that worried about it I suppose you could always put a tiny drop of Locktite on the thread, note tiny.

Don't catch and flip it. Land in your hand by using down on the stick and let the drone rest in your hand.