Low Rotor RPM

dogman1313 · Nov 5, 2023

I purchased a used Mavic Pro. When I start it it will not get over 180 RPM on the rotors and will not take off. Any ideas on how to correct this?

Cafguy · Nov 5, 2023

How are you checking your RPM ? and what exactly happens when you try to Fly it?

dogman1313 · Nov 5, 2023

The rpms are indicated on the controller. When you increase the throttle nothing happen. It never goes above the startup rpm.

mobilehomer · Nov 5, 2023

What mode is the controller? The default is Mode 2 where the left stick is throttle.

dogman1313 · Nov 5, 2023

It is in the default mode

Yorkshire_Pud · Nov 5, 2023

dogman1313 said:
I purchased a used Mavic Pro. When I start it it will not get over 180 RPM on the rotors and will not take off. Any ideas on how to correct this?

How are you starting the motors?
Are you giving the drone any throttle?
At a guess you need to multiply the RPM by 10, that's going by what I see with the Mavic 2.

RadioFlyerMan · Nov 5, 2023

dogman1313 said:
I purchased a used Mavic Pro. When I start it it will not get over 180 RPM on the rotors and will not take off. Any ideas on how to correct this?

I hope I’m still flying my Mavic when I’m 123 years old.

Try an auto takeoff.

dogman1313 · Nov 5, 2023

Yorkshire_Pud said:
How are you starting the motors?
Are you giving the drone any throttle?
At a guess you need to multiply the RPM by 10, that's going by what I see with the Mavic 2.

I start it by pulling the 2 sticks to the lower inside, the drone starts up. Then I try to increase the throttle to take off and no results.

MA2 317 · Nov 5, 2023

dogman1313 said:
It is in the default mode

This phantom post on DJI in 2014 sounds similar.

The controller slipped into mode 1 mysteriously.

Drone won't respond to take off (nothing happens when throttle up)

Hello, I wanted to see if anyone has a solution for me. I was flying the drone this morning just fine. I landed it, put in a new battery and when I tried to take off again, it wouldn't respond. I turned everything off, brought it inside and checked over everything. I went back out about an hour...

forum.dji.com

Might hook it it up to the DJI assistant to insure it's transmitting mode 2.

.

dogman1313 · Nov 5, 2023

I will give that a try.

Felix le Chat · Nov 6, 2023

dogman1313 said:
I purchased a used Mavic Pro. When I start it it will not get over 180 RPM on the rotors and will not take off. Any ideas on how to correct this?

Check the on-screen map. Are you in or on the border of either a blue or red geo-zone? A bit of a basic question, I know, but this is the only occasion where I've had something similar occur.

Yorkshire_Pud · Nov 6, 2023

dogman1313 said:
I will give that a try.

You should be able to check that the controller is in mode 2 via the app, see

from 59 sec onwards. You normally want mode 2.
Also check that the drone is set to respond to the controller rather than wifi from the phone, there is a switch on the drone see page 48 of the manual

https://dl.djicdn.com/downloads/mavic/20171219/Mavic%20Pro%20User%20Manual%20V2.0.pdf

(That it starts via the CSC may mean it is set to respond to the controller but I don't have a Mavic Pro to check )

dogman1313 · Nov 10, 2023

I finally got it to liftoff. It was out of Mode2, I corrected that and it worked. Thanks everyone. Now onto the gimbal and vision sensor issues.

Cafguy · Nov 10, 2023

dogman1313 said:
Now onto the gimbal and vision sensor issues.

What issues?

dogman1313 · Nov 10, 2023

Cafguy said:
What issues?

Tried to calibrate the gimbals and it will only go to 31%, connected to dji assistant 2 and cannot calibrate the front vision sensors. It say can not detect calibration image. right sensor has a image, left sensor has none

Kilrah · Nov 10, 2023

Then you got sold a faulty/damaged aircraft. Return if you can?

dogman1313 · Nov 10, 2023

Can't do that. It was a charity auction. I am just trying to get it to fly for my grandkid.

Cafguy · Nov 10, 2023

OK you probably have a drone that was dropped or had some kind of shock too it- maybe a prior crash.
First is it possible to calibrate without the assistant? If so take it outside away from any metal or CONCRETE and try again if that does not work and you are getting both gimble and front sensor errors you will need to replace the card on top of the gimble most likely there is your problem.
These cards were mounted poorly with no shock resistance, and a crash or large shock will usually knock some tabs on the board loose and also some of the boards etching will flake off. This is one of the reasons you will find the semi-conductor paste holding the connections together at the board.

MA2 317 · Nov 10, 2023

dogman1313 said:
Can't do that. It was a charity auction. I am just trying to get it to fly for my grandkid.

FYI, I haven't used the services, but DDS is a approved vendor here that may be able to repair the aircraft if you can't get it going.

DDS Drone Repair - Your Drone Repair Shop

ddsdronerepair.com

.

dogman1313 · Nov 10, 2023

Cafguy said:
OK you probably have a drone that was dropped or had some kind of shock too it- maybe a prior crash.
First is it possible to calibrate without the assistant? If so take it outside away from any metal or CONCRETE and try again if that does not work and you are getting both gimble and front sensor errors you will need to replace the card on top of the gimble most likely there is your problem.
These cards were mounted poorly with no shock resistance, and a crash or large shock will usually knock some tabs on the board loose and also some of the boards etching will flake off. This is one of the reasons you will find the semi-conductor paste holding the connections together at the board.

Do you have an idea of what it might cost to repair or is it too much for the drone?