SJRC F11 4K Pro strong drift - no position hold - GPS signal OK

[pan1300]

Hello from Belgium,

I am new to this forum and new to drone flying. I purchased a new "toy" quadcopter while hoping to be able to start easily with some photography with a drone. I had some first flights without any issue (each time I did a compass calibration and gyroscope callibration before take-off. During one of my last flights the quadcopter started to drift stronly and countersteering did not sufficiently help. I made an emergency landing. I have changed propellors, recalibrated but now the drone immediately starts drifting after take-off. The app shows Ready to Fly at each take-off but as soon as it is in the air (and I do not touch the controller) the drone starts drifting very fast to the left side.
Any help would be welcome.

Thanks.

Laurens

 

[davidhk129]

I don't have much to offer except 2 points which you may or may not know.......

1. The drone needs 2 sets of props. 1 set of 2 props labelled A which are to be installed to the 2 arms labelled A, and 1 set of 2 props labelled B which are to be installed to the 2 arms labelled B. That cannot be switched around.
2. Make sure the props are installed not too tight or not too loose. Just snug.

P.S. Does your F11 have "trimming" option? Check your user guide/manual.

Your F11 has Optical Flow Positioning and GPS. It should stay in mid air steady like a rock. The reason it does not appear so is mainly because , in my opinion, your props are not installed correctly.

 

[pan1300]

Hi David,

Thanks for your prompt reply.
I just double checked the props and you are bang on the right diagnose: props on one side were mismatched. I switched these and will give it another try to fly tomorrow. It looks like you have saved the issue but I will confirm tomorrow.

 

[davidhk129]

Take out your user manual.
Go to the heading : Trim under No Gps Mode. ( I think it's page 15).
It shows you how to fix the drone "drifting" issue.

 

[pan1300]

Hi David, thanks for the extra info. I will have a look at it. Will the 'trim' also work with Gps mode set to 'on'? I am used (as a beginner) to always have gps on.

 

[davidhk129]

Hi David, thanks for the extra info. I will have a look at it. Will the 'trim' also work with Gps mode set to 'on'? I am used (as a beginner) to always have gps on.

No, do it under No GPS mode. GPS mode will disguise the imperfection.
Only way to "trim" it properly is to let the drone fly "naturally", then you'll know what needs to be trimmed and how much trimming required.

 

[pan1300]

Ok, thanks for the advice. I will try to have this all checked today and will report back here.

 

[pan1300]

Hi David, sorry but no time today to get out and give it a try. Hopefully tomorrow...

 

[davidhk129]

As long as you have the props installed correctly, and compass and gyro calibration are done, you shouldn't need to do the trimming.
Remember, wind is a factor. Depending on how strong the wind is, the drone might drift a little because of that. You have to live with that.

 

[pan1300]

Hi David,
This morning I had the possibility to give it another spin, so a short update. The prop change already made some difference as I can now control the drone again, thanks for the tip. As always, I did the compass and gyro calibration before getting into the air. After take off, the drone stays a moment in place but then starts to drift, not just to one side but it is like it starts to fly a small circular movement which increases step by step. I can get it back in control as long as I stay in camera mode (slow speed). I did not yet try to turn off GPS mode so I will give this and the trimming a try next time I can get out. I will give an update after that.

 

[davidhk129]

Question :
After calibrations and the drone is ready to flight, let it take off. Don't use the controller. Leave it alone. Will the drone stay put in mid-air without your controller input?
It is supposed to.
You said: it starts to fly a small circular movement.....
If you take you left hand off the left stick, will it still do that?

 

[pan1300]

Hi David, I am touching no stick at all. Not left and right. I just push the left stick for take off and then let go. The drone should then keep position but that is only for a few moments. Then it starts to make a small circular movement (jaw?) Which increases then slowly untill the drone gets out of balance and I have to intervene.

 

[davidhk129]

Looks like you will need to do the trimming.

I have many toy drones, some expensive some cheap. Never have situation you encounter.

 

[pan1300]

Ok, I will give the trimming a try. Thanks!

 

[davidhk129]

Remove the props, one at a time. Check the axis where you insert the prop into, make sure no foreign objects are stuck there. Stuck objects around the axis will prevent the props from spinning freely, hence drifting.

 

[pan1300]

Hi David,
Sorry for this late feedback, but bad weather conditions kept me and the drone inside for some days.
But, the good news is that the problem is solved and I want to share my findings with you and other users that might run into the same issue. I know, you will recognize this as a beginners error ;-)
First of all, changing the blades was a step in the right direction. This helped me to get the drone back under control but still I had trouble in not being able to keep the drone still when not touching the controller. Trimming did not help to solve the issue. I had that much trouble in keeping the drone in balance that I had not really time to look at the to the controller attached phone display. Until I noticed a short popup message that the drone lost its compass calibration. This message appeared randomly. After each recalibration I had the OK to fly but some seconds later after take off the message reappeared. And then I saw the light...
I wear a Garmin Vivoactive smartwatch and to even make it worse, with a metallic wrest lock. So all bad things to successfully calibrate the compass...
After taking of the watch and doing a recalibration, all problems were solved The drone goes up and stays in a stable position when releasing all controls on the controller.
I still want to thank you for all your support and tips. Great job!
Best regards,
Laurens

 

[davidhk129]

I don't understand why that Garmin smartwatch etc would create issue to your drone. Maybe the Garmin GPS has conflict with your drone GPS?
Anyway, nice to know you have the problem resolved.
Enjoy your F11. Happy piloting.

 

[pan1300]

Hi David,
Probably the reason is that this watch generates some magnetic interference when calibrating the compass. The watch has also a magnetic kind of lock. If I take of the watch, no issues. I assume the brand is not important but the magnetic interference generated by these kind of watches and magnetic locks.

Enjoy the Holidays!
Laurens

 

[gregb49]

Sorry to pick this subject up so late, but I have a JJRC X11, upgraded to 4K, which I believe is an identical quad. It is very stable in my experience. I concur with your compass calibration findings. It seems more sensitive to metal objects or transmitting devices than other drones that I have. Good compass and gyro calibration is essential.

Glad to hear that you have solved the issue as it is a great drone to fly, and at its high weight, is not buffeted by winds as much as my sub 250gm drones. It's Return to Base function has been fautless, when it looses signal although with current UK flying restrictions ie VLS and weight restrictions mean it is not as much fun to fly as it used to be.