Descent optimization

BirdDrops · Oct 31, 2023

For the mini 3 pro I am trying to find out :

- What direction do the propellers spin ? (when looking at it from above)
- I remember a friend of mine who had a Mavic series saying he could descent quicker by doing a down + rotation movement at the same time , instead of simply down . Does this also apply to the mini 3 pro is what I am asking myself now ? And if so , is right rotation different/better than left ?

IronSpear · Oct 31, 2023

BirdDrops said:
For the mini 3 pro I am trying to find out :

- What direction do the propellers spin ? (when looking at it from above)
- I remember a friend of mine who had a Mavic series saying he could descent quicker by doing a down + rotation movement at the same time , instead of simply down . Does this also apply to the mini 3 pro is what I am asking myself now ? And if so , is right rotation different/better than left ?

Gosh I always thought it was a bad idea to descend in a rapid spiral. Something to do with a "vortex ring state". I may be wrong. Great questions. Have fun.

Yorkshire_Pud · Oct 31, 2023

The propellers on one diagonal rotate in one direction, the propellers on the other diagonal rotate in the opposite direction.
This is part of the mechanics behind their control of yaw.
If you look at a propeller each blade has a high edge and a low edge, the propeller moves towards the high edge which is also known as the leading edge.

This is also why the propellers and arms of one diagonal are marked, as per page 29 of the drone's version 1.6 manual.

https://dl.djicdn.com/downloads/DJI_Mini_3_Pro/UM/20230728/DJI_Mini_3_Pro_User_Manual_v1.6_EN.pdf

There is no 'faster ' way to descend.
The horizontal movement in any direction is to avoid the air of the downdraft beneath the drone, you can google "vortex ring state."

slup · Oct 31, 2023

BirdDrops said:
For the mini 3 pro I am trying to find out :

- What direction do the propellers spin ? (when looking at it from above)

All DJI photo drones have a "props in" configuration (props turn in towards the front & rear side). Note that a rotational torque is generated in the opposite prop rotation direction.

BirdDrops said:
- I remember a friend of mine who had a Mavic series saying he could descent quicker by doing a down + rotation movement at the same time , instead of simply down . Does this also apply to the mini 3 pro is what I am asking myself now ?

As long as the props are rotating & the flight controller works as it should... DJI photo drones descend speed is capped by the software, no matter how you fly.

This is the max speeds for a Mini 3 Pro:

IronSpear said:
Gosh I always thought it was a bad idea to descend in a rapid spiral. Something to do with a "vortex ring state". I may be wrong. Great questions. Have fun.

It's exactly the opposite to what you suspect... Vortex ring state is avoided by adding in some horizontal movement together with the descent.

Meta4 · Oct 31, 2023

BirdDrops said:
For the mini 3 pro I am trying to find out :

- What direction do the propellers spin ? (when looking at it from above)

Two rotate in a clockwise direction and the other diagonal pair rotate anti-clockwise.

BirdDrops said:
- I remember a friend of mine who had a Mavic series saying he could descent quicker by doing a down + rotation movement at the same time , instead of simply down

Your friend has no idea what he is talking about.

solidhouse · Oct 31, 2023

Meta4 said:
Two rotate in a clockwise direction and the other diagonal pair rotate anti-clockwise.

Your friend has no idea what he is talking about.

Some DJI drones such as the Matrice 300 and Mavic 2 Enterprise Advanced will descend faster when moving horizontally.

3rdof5 · Oct 31, 2023

If you understand how a propeller works then it's quite easy to determine their rotation by the pitch of the blades.

kiley · Oct 31, 2023

IronSpear said:
Gosh I always thought it was a bad idea to descend in a rapid spiral. Something to do with a "vortex ring state". I may be wrong. Great questions. Have fun.

The electronics in DJIs drones would likely prevent the untoward effects as you describe from occurring.

kiley · Oct 31, 2023

Meta4 said:
Two rotate in a clockwise direction and the other diagonal pair rotate anti-clockwise.

Your friend has no idea what he is talking about.

I just perform an emergency shutdown and let my drone drop from the sky. .....lol

kiley · Oct 31, 2023

3rdof5 said:
If you understand how a propeller works then it's quite easy to determine their rotation by the pitch of the blades.

That is a matter of fact. Stout observation.

Meta4 · Nov 1, 2023

kiley said:
The electronics in DJIs drones would likely prevent the untoward effects as you describe from occurring.

No electronics necessary for that.
Vortex ring state was never caused by spiraling down.
It was caused by descending vertically.
But DJI eliminated the possibility back in 2015 when they offset the motors so they are not aligned vertically.
Since then, vortex ring state incidents are no more and you can safely descend vertically.

Harryscopic · Nov 5, 2023

About the descent, I think now it's a matter of stability, not safety. Descending through turbulent air is not as clean, so it can take more effort to stabilize the drone and make it progress slightly slower.