Using
Fsi6x transmitter
FsiA10B
Check the documentation for your receiver failsafe actions, it will probably be “hold all existing outputs” or something similar. You may have to bind the receiver again while the transmitter throttle channel is set to something like -110% (in OpenTX terms) or about 970 PWM using trim. Then set the transmitter throttle back to normal after binding and test the failsafe on the ground.
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There’s a significant physical yaw/motor imbalance like motor mounts are twisted on the frame, or the frame itself is twisting. People have even found CW and CCW props are not always producing the same amount of thrust.
Your clock-wise motors, 1 or 2, will be twisted on the frame, and motors 3 and 4 have to work harder to counteract 1 and 2
Yaw is not tracking so well because of the motors being twisted on the frame
You’ve got some high vibrations there, you will want to look at prop balance and also antivibration mounting of the flight controller. Secure any loose wiring too.
I suggest you dont stop at the yaw problem though!
You’ve got a lot of default values there. You really need to use this spreadsheet or the MissionPlanner plugin ( Alt A on the keyboard) to set some parameters based on your quad, and then run through the tuning guide.
https://ardupilot.org/copter/docs/tuning-process-instructions.html
Since you said it rolls after you launch, you might want to redo the accel and RC calibrations again.
Check you transmitter trims are NOT set, but all centered.
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Thanks Shawn.
Will test and get you back…
I did exactly what you said.
Now RC failsafe is working.
Thanks shawn.
Dealt with this as well. The motors are quite sensitive to being just a tiny bit rotated. Took me a number of flights to get the thrust so its pointed straight down. My bubble level would say it was level but the logs said otherwise
Thanks for mentioning props might produce varying thrust, Shawn. I hadn’t considered this and been using cheap props as I had a couple mishaps early (thinking I would switch to better props when I ironed out everything).
Hi Shawn,
As per your suggestion
- Used plugin and updated some recomended parameters.
- Did accelemeter calibration.
- I did not used any antivibration mounting. (need to get) For now using Double sided tape only.
I went for a test flight with all changes above
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Loiter is performing is good. holding its position perfectly.
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Rolling problem is fixed. Motor (1 and 2 ) heating problem is also fixed.
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But some time VIBE is becoming red color when I move the drone in the air. Here is the log file…
https://drive.google.com/file/d/1zhv9Ormxm2LZSI8v0ljMK4YJiJWcGEXV/view?usp=sharing
Is that fine? OR Can I reduce the VIBE if I go for AUTO TUNE?
Please le me know.
Thanks.
The vibrations are a physical problem and you must definitely fix them before going to autotune.
It is risky to fly in anything other than Stabilise mode if you are getting vibration warnings.
Once you have vibes fixed, you can set up Harmonic Notch filter properly and do Autotune. We’ve got a 700mm/2.5kg quad with V5 Nano that performs like something half it’s size after that process. Elsewhere I might have called it a 650mm frame, but I measured it and it is really 700mm.
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Thaks shawn.
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Could you please suggest some antivibration module?
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Also I am using F450 frame. Is that fine? I suspect the frame only.
Those frames are a bit too flexible and can enhance the control issues - but they do usually work in the end.
You will probably need to balance all the props (usually evident in X and Y vibrations) and maybe improve whatever is mounting the flight controller now, something like in this discussion:
Since you are using the Pixhawk 4 from Holybro it looks like on their web site they just use/sell the foam mounting pads. That may not be enough, or you might have done something wrong.
Make sure the wires aren’t pulling tight on the flight controller, rubbing against it or vibrating around unnecessarily in the prop wash.
Also keep in mind if you add weight, like a camera, you will probably need to increase the prop size to 9 or 10 inch.
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I am using Emax 935 kv motor and 4s battery.
They recomended
- 10 inch prop for 3 S battery
- 8 inch prop for 4s battery. (Currently using)
Can i use 10 inch prop? Will it cause for motor heat increase?
I just mentioned it because your hover PWMs are right in midrange where they should be.
If you do add weight you’ll just have to see how those props and motors handle it.
Best to check all the specs, maybe run it through ecalc. ecalc costs less than the price of a set of props, but you can use it for free with limited choices.
https://www.ecalc.ch/xcoptercalc.php
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Okay shawn.
Thanks. Will check and let you know.
Hi Shawn
With your suggestion I did some modification to my frame and finnaly got these results below.
Please check them and let me know whether everything is good or need any changes.
That looks good, be sure to follow through all the rest of the tuning. There’s hundreds of posts here covering every aspect.
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Okay Shawn.
Thanks for the reply.
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Hi Shawn,
Suddenly motor 1 and motor 2 is not working.
2 days before i have flown and landed properly. After 2 days I went for flying today 1 and 2 motors are not running.
Please let me know what might be the problem.
Either a connection/broken wire problem, or ESCs have failed.
If those are genuine Emax ESCs they should be good.
If the motors connect to the ESCs with bullet connectors check all those, and the wires tend to break right at the edge of the bullet connector.
Check soldering.
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Hi Shawn,
Everything were perfect, but still 1 and 2 were not running. I even tried esc calibration, after that also 3 and 4 were only working.
Then I uploaded Rover firmware. After completing the 100% uploaded the 3 and 4th motor were spinning in another few seconds followed by 1 and 2 motor started to spinning.
Then I disconnected the battery, again uploaded copter firmware and again did all the basic calibration then everything came back to normal.
Now the drone is flying properly.
But why did happened, that am not able to figure it out.
Hello shawn,
I have replaced my motors, ESC’s and propellor with T- motor combo pack (F-450). Completed the test flight.
Please check the LOGS and suggest for any changes.
https://drive.google.com/drive/folders/1-jgIYvC31PkqAw_SuRmu7wW9fX172MEn?usp=sharing
Thanks