Micro tuning techniques - different than larger quads


#81

@NotFastEnuf: Dude - Serious Virtual Fistbump! Thanks for posting this - Extremely helpful!

I’m glad you mentioned that your P values are in the 3 digit realm - I thought I might be going nuts until I read this because my P values have been going through the roof - anywhere between 100 and 120 on roll and pitch and I’m having really good response from my crafts.
I don’t understand why default PIDs are so, so off in the first place - I mean, I do - but why hasn’t someone established some defaults that are much closer to real-world values?

A Wiki with quad tunings based on type, weight, size, motor and FC would be awesome. They could be rated by those that download and use the particular tuning - much like “guitar chord/lyrics” websites.
Just a thought…


#82

Got pitch and roll P linked to a switch. It changes FAST though!
Can’t find a setting that changes that.

Though I just had an idea, I bet it’s treating it like a knob and if I dial the TX back so it’s at like 1400/1500/1600 instead of 1100/1500/1900 it’ll go slower.
Rubber duck debugging right here. Will report back.

EDIT:
Nope. It either changes violently or not at all. I’m missing something.


#83

It’s supposed to change 1 point per second. So you can just click the switch like a momentary switch and get an increase of 1.


#84

Yeah… it’s more like 45+/second. Touchy.
That said, doing some awkward flying around (2 hands doing the job of three hands) in the ~19MPH winds flowing around / over the house / fence / trees (yes, there were crashes. A number of them, including one that knocked a motor slightly out of it’s mount. It later came out mid flight and caused another crash.) I have a P of 110, an I (untouched) of 31, and a D of 162 for pitch and roll. Haven’t touched Yaw yet, it’s still at 80 P and 30 I.

End result?
It’s windy as hell out there, the air is a mess (19mph, plus swirls as it goes over/around fence / house / cars etc, I’m on a hill facing the ocean where the wind is coming from too), and the only way you can really tell in the video feed is a faint twitching now and then, and the battery voltage dipping (yay OSD!) as the motors spin way the hell up to counteract something.

This.
Is.
Awesome.

What should I do with I? Or is that somewhere in the ~80 posts I haven’t reread?


#85

Lmfao, I’d think no more than 45 or 50. Bring it up 5 at a time and stop when it holds a line well over a distance. Take it too high and it will feel like you’re carrying too much momentum into corners & slightly robotic (although the d setpoint stuff hides a lot of that now). If you have any thrust imbalances that cause a small quick change of attitude on throttle punches … (and you’re on 3.1.6) - we will address that with antigravity gain. Just remember that I is the last guy to the party. That should help you analyze any unwanted behavior wither caused by I or because it’s too low.

Nice to hear it’s holding wind well. Have you done anything with setpoint weight and transition to get the feel you like?


#86

I’ve got 20 mph sustained with higher gusts here - flight time was down 1 min but other than that it took it really well. I know what you mean by the juice getting sucked down fast when it’s fighting. Just a stellar flying experience. A few times I got some really minor P oscillation - I think maybe there is a reasonable limit we should place on our expectations. We are working with a pretty limited amount of power.


#87

Ahh that’s fun, flying in the wind. Intense when you find a place it curls around. Went from hovering along to with some slip left to going up and backwards at 15mph due to clearing the edge of the garage. Totally controllable though! Crazy stuff.

Ended in a crash of course, but everything survived. The transition from outside to in the garage caused issues.

D transition was 0.2 by default, with a setpoint weight of 1. Dropped setpoint to 0.85, will see how that feels later or tomorrow. I can sense a neighbors yard trip nearing me flying in this wind and I’d rather pass on that one. The wind of course is blowing across the narrow way of my yard. Were it the long route I’d be golden.


#88

Nice! I get some strange wind turbulence in my front yard flying space too. Lots of giant Oaks surrounding a culdesac and I have been flying above, in, and below the tree line. Areas of strong lift right next to downdrafts… fortunately no matter what direction the wind is going - the air always behaves the same due to structures in this space and I’ve learned it well from years of flying micro planes here.

The d setpoint, just to give you more info, at .85 actually softens your sticks at the initial response to input a bit below 1 to 1. I find that I am pretty far from perfect and a lot of unwanted behavior is actually my fault. With this value, it’s kind of like the fc does more of what I am “suggesting” and less of what I am imperfectly actually “telling” it to do. A better pilot than I would hate this - but it made me look like like a better pilot! Hahaha. Curious to see what you think of it!


#89

Lol! I’ll let you know what I think about it.
On one hand my sprint kart is how I generally prefer things (instant, tight, twitchy), on the other hand… I’m not a great pilot either.

Your description of your flying area sounds very similar condition wise. I was working on getting back in the garage door while not hitting the ground, then got out of the downdraft and about hit the header bar (or did, not sure), emergency throttle drop and dodge got me inside but with 30 degrees left roll, corrected that just in time to hit the wall and that was the end of that.
No damage though, so no biggie. Just a bit more abrupt.

I have video of having to rapidly move my foot out of the way of a landing P-twitchy quad too, pretty funny.


#90

This is what is being tuned btw.


#91

Very nice. That’s the 0820-15’s right? I miss that combo with the afuntas. A ripper for sure at that weight. I must say though, the cheapo 0820 standard unrated replacements on gemfans are giving me the same 4 min flight times and really close to the same punch and speed that I had on the 15’s plus afuntas - and I’ve got more blade in the air. I’m not sure I’ll go back to the 15’s since you can get 20 of these cheapos for 25$.


#92

Yeah, this set is Kados 14750 or something like that.
Between them, MMW 15kv, and Banggood sourced (Crazepony? Racerstar?) 14.5kv they all appear pretty similar.
Ben’s though, they don’t have any holes for sand to get in. This is important when you fly at a grass/sand field and crash in a sandpile after an unintended scratched landing on a picnic table (note: turn air mode off, THEN land). Oops. So much for the brand new Kados. Actually the sand seems to have lost the battle between casing and stator wires though, so it’s all good.
The Banggood ones were red, that was fun. One of them started eating a bushing after a decent amount of flight time.
Ben’s there was a grade A catastrophic RX issue and I bent a shaft. Still flies well enough though so whatever I guess.

I’m hard on motors.

What size Gemfan? Link?


#93

Just the 65mm with the annoying hole that’s too big and needs superglue. I’m gonna try the kingkong 65mm next. Fresh pack to open tomorrow evening - broke the last of my gemfans today. Toying with queen palm trees in 20mph wind. I like a challenge. Palm tree won.

Anyway, too much blade for the 15’s in my opinion. Ran too hot, flight time short, felt less punchy and too floaty. Come to think of it, same palm tree clipped me with my last 15’s, spun me, and burnt the motor mid air just from hanging it up in that brief moment.


#94

Yeah I tried those 65mm (generic edition, but the Gemfan 65mm I found look the same). No more punch than the BTG 55mm (parrot clones I think) or Afunta, but ran very hot on 15kv. Lots of overhang over the center bit of the kk100 too, not very useful airflow wise.

That palm tree has it in for you.


#95

i too love how bens motors have no wholes in them for sand to get in them… They are also silky smooth and way quieter than alot of other brands I’ve tried… i also find the afunta 55mm props to be better for my purposes lately than the gemfan 65mm, but im sure with the proper and correct tune those 65mm props can be just as or maybe more efficient and rip at a lower throttle value and provide nice thrust… but they also catch the turbuelnce of the wind much more… which is why I decided to start tuning on 55mm afuntas… 55mm afuntas rip, and punch out fairly nice… This is just a noobie pointing out his observations though!


#96

I’m 100% with you! Not sure about the 65mm efficiency thing - but I will say the only motor I think they are well paired to if you want decent flight times is the cheapo slow unrated ones. That combo under 55 grams flies well but I spend a lot of time at 100% throttle. It’s not a show stopper for power but it’s at least in the beginning of what I consider the fun range. As for tuning with 65mm - my feelings were the same in that until this last experience - I’m in love with them now and really use the extra bite from more blade to stick it where I want with less momentum slide.

Finally I totally agree with the better quality of mmw motors. You can hear, feel, see the difference!


#97

So this just in from boris b…
https://www.rcgroups.com/forums/showpost.php?p=37279531&postcount=47305

Basically talks about a similar thing to what we attempted to cover earlier - reducing filtering for better performance … Although it seems I got it backwards starting with removing d notch first instead of last. Of course I did mention that I was going for the most aggressive gains as opposed to what boris recommends which is to make these changes slowly. I am virtually prop wash free now on 8.5mm brushed but still get a touch here or there if I don’t nail my exits from maneuvers and come out flat. This may maybe worth another visit… (this time in the order that boris reccomends :smile:)


#98

FWIW - I have 4 micro builds - I was able to set d_lowpass_type = PT1 on 3 of them - the 4th quad, setting it to PT1 made it shoot straight up with no throttle control (1000 to 2000) in other words no matter where the stick was, I was getting the same rpm from the motors…changed it back to BIQUAD and all’s good. Interestingly enough, I was able to remove the 1st Notch filter without any adverse affects.

Note: Just in case you forgot or didn’t realize, you have to log into each profile in order to store changes.

I would love ability to:
1 - setting global parameters (profile independent)
2 - copying of profiles (Copy Profile 0, Profile 2)
3 - Within the GUI - Question box asking me to apply settings to (Global, Profile 1, Profile 2, All Profiles)

@NotFastEnuf - Can’t thank you enough for bringing this subject up and also freely sharing all your wisdom - cool beans!


#99

I must say Woooww, Amazzing !!!, I got a very good result in turning my 95 and 120 mm quad, on the 95mm I even can remove the 1st Notch without introduce any problem


#100

NotFastEnough - Sorry to derail the thread ever so slightly but do you have your PID values for the Silverware DM007 2s build that you made? I have done similar to Ikki’s build and using 1s batts but I’m finding it difficult to tune right. Thought I had it down but it was slightly windy yesterday and it threw everything off. A starting point of with something I can compare to would be really helpful as I know it’ll be different due to the frames.