I have been there and I have done that.
I stand by what I said.
I wrote the control and navigation code and tune aircraft for a living.
Sorry you are wrong.
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So it is better, for example, on my 25kg quadcopter to remove the 7 kg payload to do the autotune? If so i’ll run it again. I have done it with payload attached since it’ll nevet fly without, but if i understand it correctly if i remove the payload for whatever reason i could run into trouble.
If you are never going to remove the payload then keep it on as that will tend to give you a sharper tune for that payload. Just keep in mind that if you do remove it or change it the tune may be unstable or a little over tuned.
Ok thanks for your advice!!
Seriously? What happened to your minimum payload rule?
Are you really questioning the person that actually wrote the software you fly?
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I said one should tune with the full intended payload aboard. I was told I was wrong and that tuning with a minimum payload aboard is “better” because it will produce a more stable tune. He goes on about tuning with full load and then removing the load will make the aircraft unstable. Then he tells you to tune with the full payload. So which is it?
I built each of my aircraft to serve a specific purpose. Each aircraft has a unique fixed Take Off Weight (TOW). Each aircraft was tuned at that weight. My aircraft are stable, their handling and flight characteristics are consistent, and their flight times are repeatable. Is that not what tuning is about?
I think it makes perfectly sense. If you never remove the payload than tuning it with payload is the way to go. If it happens to remove and fly without payload than it is better to tune without. This is what i understand and if it comes from the person who develops the math behind it than i take it for good 
If you are never going to remove it that would be the minimum payload wouldn’t it.
If you are never going to remove the payload then you don’t need to worry about it becoming unstable without that payload do you.
As I said, this is wrong. Tune with the minimum payload.
No, I said if you are never going to remove it then it is safe to tune with it. (Because that would then be the minimum payload).
No, that is my idea of getting an aircraft flying before I start tuning.
To summarize for everybody:
- Increase in aircraft weight tends to allow higher PID values.
- Tuning with a payload and removing it can result in an unstable and therefore dangerous aircraft tune.
- So the general rule is tune without your payload or at your minimum payload.
If you are never going to fly without your payload or you have a fixed configuration that will never change then you can safely do autotune in that configuration (your minimum payload).
The one thing to be careful about here is if your payload is on a vibration mount or is flexible. This can result in Autotune giving you a bad tune. Here you may benefit from a tune without the payload. Even then a flexible payload or vibration mount may interact with your controllers to cause oscillation. So be careful with any flexible payload or payload mount.
The other thing to remember is batteries are payload so if you intend to fly on a partial battery load it is a good idea to tune it without payload and with the partial battery load.
Generally a good autotune will be so sharp that you will never notice that it is softer at full payload.
That reminds me. An extremely important exception to all this. While you should tune the aircraft for minimum payload you should set your ATC_ACCEL_XXX parameters for the maximum payload you intend to fly. A good rule of thumb would be to reduce the values given by Autotune by
MinTOW / MaxTOW.
To give you an idea I reguly achieve a 4:1 max TOW to min TOW without any tuning changes over the full battery voltage.
If you follow these general guidelines then you will give yourself the best chance of achieving a well tuned aircraft across a wide TOW range.
Another tip is make sure you set your MOT_BAT_VOLT_MAX and MOT_BAT_VOLT_MIN. I also recommend using MOT_PWM_MAX and MOT_PWM_MIN so you don’t have to recalibrate your ESC’s if you connect a different radio.
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I get it. It all depends on what your definition of “is” is.
Interesting explanation. What is TOW please?
Take Off Weight. Also known as AUW, or All Up Weight.
I think this was long overdue.
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I have seen a request for a Wiki Dev weekly chat.
Do you know WHERE this weekly Dev chat is?
It wasn’t evident in Mumble where I assumed it would be.
I am happy to pitch in, just need to know the details of where and when (still Wednesday version of the Dev chat?)
I just asked Randy and he told me “there’s a wiki meeting on Wednesday mornings… same time as the dev meeting but on wed instead of tuesday”
So it looks like you may have hit one that was canceled or something.
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Hi Leonard.
Fantastic description. I was quite surprised, that many steps I did similar, but it took me almost 1 year and in minimum about 100 flights, to get there.
With this wiki I think you helped now a lot of people to overcome frustrating tuning hours and also crashes.
BR
Harald
1 Like
I’m setting up to fly a big X8 similar to above (slightly bigger) T-Motor U10II KV100 and 30" props. I’ll follow your tuning guideline. However noticed MOT_BAT_VOLT_MAX and MOT_BAT_VOLT_MIN will not work for 12S? Range stops at 35V.
Yep, change that in the parameter list directly.
Thanks I will change the parameter range of that one.