Practical PID Tuning - Part 7 - DYS 5x4x3 Vibration Madness 

Of course. He's a professional.

Hahahahaha. Not professional at Audio that's for sure.

Yup. This is why I wanted to share this video!

+Cw1Xpro the filtering will be revolutionized by Betaflight notch filter, so I'll just make it then.

+Amber Meows yes, definitely the DYS props.

Hey Joshua, maybe you can try the Dal 5040 triblades, it's the same blade profile as HQ5040 tri and DYS 5040 tri, but much better balanced. I've been able to push D to the 40-60 range on a similar 5in setup with no issues (or propwash!). The motors only gets a little warm, but is sensitive to prop balance. If a blade is bent after a crash, that motor will heat up pretty quickly, similar to what you experienced with the DYS prop with D set to 47.

That is exactly what I hate about DAL.

Maybe I should change my slogan to "life is too short to balance props."

+Joshua Bardwell Right on!! So against balancing miniquad props.

Hot glue? Do tell.

I'm just about to upload a video form the test. Don't mind how my shit flies XD I'm going through my first F3 tune sins the naze came out. Your videos have been a great help. Hope you an ckeck out my log ones i cant get any further. Oka so back to the mod. Super easy. I just teared away the small piece in the housing that holds the mic. Then i hot glued a maybe 1-2 mm layer around the mic. Pott it all in place and your dun. I have some better mic's but wanted to try this first.

+sciullo779 yup. But that didn't exist yet.

Yeah, and I prefer to fix a problem instead of mask it, but if we want durable props we cant expect perfection. I just wonder what the dterm handling differences are between 2.6.1 and 2.9.1 that they make such a huge difference in terms of heat output and tunability.

The difference is that the default filter was raised significantly. There is much, much less filtering in 2.9.1 than in 2.6.1. If my memory is correct, anyway. What are the gyro filter settings in your setup?

I actually set the exact same defaults 80/70 as 2.6.1, but like I said looking through the release notes P term accelerator was added, dterm math was modified, from the cli dumps Dterm averaging was removed, etc. Im sure its for the better on cleaner copters, but for most of us running slightly noisy motors/props, it can really limit the tunability of them (at least my copters)

+sciullo779 you can turn dterm averaging back on in 3.0 at least. Maybe 2.9.

+James Woodsrc eventually

For X frame, I like the QuadQuestions QQ190 because I think it has a great camera pod design.

My thanks.

+Albert Kim (marblekit) I'm working on that

Thanks. I can do adjustments but always have to land first. I'm really interested in how you do this while flying. Love your videos.... keep up the good work!

+Albert Kim (marblekit) just flip switches with one finger and fly with the other.

+Joshua Bardwell I too would love to see how you've set this up. One of the things that continues to put me off getting the best tune I can is the tedium that comes with having to "set pids, fly, no good, land, hook up to laptop, adjust, fly..." You knew the drill. Here in rainy England we rarely get to fly, so as long as the quad flies ok, we'll take it when we can. Also, I'll just take this opportunity to say a huge thanks for all the time and effort you put in for us mere mortals. I have learnt so much since subscribing to your channel. You've given me the confidence to push my boundaries without too much fear. Keep up the fantastic work. And in the words of our messiah "happy flying" 👍

If you are in autolevel mode, here is the fix: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-otJNzZrE-yk.html

+Anatoliy Pishenin I have a video coming out about this soon. It is not that thing you said.

So far, but I am still looking for something even better. The KK tris are great performance but their durability is not quite where I would like it to be.

It's an H2N Handy Recorder microphone.

this thing is what you use..? amzn.com/B005CQ2ZY6 So, was that a jet I heard for reals..?? also noticed most of vocals are on Right channel. - I assume you did that when mixing video/audio on purpose?

I didn't mix the audio that way. The unit has quadrophonic microphones and it can mix down to stereo in real-time. In later videos, I have started mixing my voice over down to mono, or manually panning it to center at least.

+Dashz try playing with D term setpoint

No way Josh... Do you think it could be hardware issue? My battery is a very cheap 40c 3S 1500, Im using 5040x3 with sunnysky edge 2204 motors and the battery gets warm after flights, could happen that the battery cannot deliver enough amp peak to stop the quad in place after a hard roll? Idk but it gets frustrating.

+Dashz maybe that's it.

+neo36w eno36w I try to tune P first.

For sure, but I'll be damned if I'm putting those stupid DYS props back on to find out. Oh heck, knowing me, I probably will.

+DJMOTO acro. I also have air mode enabled. Air mode is not a flight mode like acro or angle. Air mode adds on to the flight mode. It's a change in the mixer logic.

thanks for the info. out of interest what's the spec on your quad ie weight thank Dave

+DJMOTO around 550 grams.

Joshua Bardwell is that 550g with battery 3s 4s ? what esc's , motor's and props are you running sorry for all the questions I am trying to give myself a good chance of making a good quad thanks again Dave

+ML Caldwell defaults are great.

+Joshua Bardwell thanks Josh

+Peketronics if you've explored the limits of the tune, the only thing to do is focus on the mechanical. The first thing I would do is try changing props.

+Joshua Bardwell I'm going insane on this one, of course I've tried new props, even different pitch and shapes, they are balanced, no vibrations, motors too, and it happens on all my 4 quads, this is my setup, naze32, emax2205, dal 5040x3 or dal5045x3 or gemfan 5040x6 or gemfan 5050x3 all new littlebees 20A and other quads littlebee 30A also my center of gravity is checked of course, I've even tried to put the lipo as forward as possible to try to prevent the nose liftoff LOL what do you think is wrong??

It is called, Quadcopter's nature or "real world situation" Boris introduced in the last update an antigravity option that will probably help you. That thing you were experimenting happens to 99% of the quads.

+Dashz in Betaflight 3.1 set anti_gravity_gain=3.

I don't agree with that analogy. It is the same as controlling a motor in a control systems feedback, at least at some basic level. Here is a good explanation. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-0vqWyramGy8.html

Never mind. I just found your Taranis advanced pgming tutorial. Cool!

I've got a video coming soon about that.

Pretty sure he's using the "adjustments" then assign it to a switch and excited to learn about it as well.

Probably not.

I can imagine some scenarios where reducing the motor update rate would filter the D term so as to reduce the heat. But if what you want to do is filter the D term, why not just use the low-pass filter? That's what it's for.

If your motors are coming down cool or warm, but not hot to the touch, then tune however you like.

+Joshua Bardwell just warm alittle after 4-5 minutes of flight. Thank you

I was going to post asking pretty much the exact same question. I've always been afraid of going over 40 with D. I finally setup the adjustments tab and went out and tuned. I tuned based on feel rather than numbers. The biggest thing that annoys me is bounce back. I finally managed to tune it all out, P's are in the 80's and D's are in the 60's. Motors come down warm, anything higher than 70 on D and they start to get hot. But 60's seems OK. Can't figure out why my numbers are so different to everyone else's. I realize that every quad is different but I've never seen a single person post saying their D's needed to be this high. D traces in blackbox look horrible, but it flies amazing. The other thing thats strange is that no matter how high I go with P, I can't get high P oscillations. Is there something happening in betaflight 3 thats hugely different to prior versions? Running pretty standard gear, xracer v3 (4 and 8khz), littlebee's and cobra motors.

Later versions of betaflight are MUCH better at resisting P term oscillations. Oscillations may only come out during hard propwash scenarios. I sometimes end up with D gains around 50 or 60. If the D traces look bad but the copter flies well and the motors are coming down cool, don't worry about it.

Good enough for me, Cheers mate

+Ardy Seto Priambodo try using TPA?

Try using the DAL props brothers of the Dys, and you are good to go, more balanced, smooth and silent.

Maybe you just need more TPA and tpa_breakpoint more higher...

+ABMNS PRODUCTION Will try tomorrow, thanks man!

I had same problem with Dys props. No matter how I tuned it, still had them on punchouts and certain throttle ranges. These props suckk!!!

Yes. I've flown Cicada on the QQ190 and Canis M4. They are good ESCs, but I don't have enough data for sure to say that they are worlds better than a good F390 ESC.

I didn't feel that they were "worlds" better initially, until i went back to my xm20 ship yesterday, after flying the cicada's exclusively for a cpl weeks. They are in fact WORLDS better. It's like going back to SD tv after watching HD tv for some time.

+Guy Rook you might be right. Like going from PPM to SBUS. At first it feels subtle until you go back.

I have a hunch that it is better to have D cutoff higher than gyro cutoff, but I haven't tested to verify this.

raceflight default D cutoff is 45hz lol but its true that D in raceflight works differently.

Anyway, you should try it and maybe you will be able to get a better tune ;)

+neclovekSK we can't focus on a single metric like this and judge a whole firmware based on it. Thar just leads to the same childish "my firmware can beat up your firmware" nonsense that I loathe.

Joshua Bardwell I am not saying anything about it being better, i am only saying that it uses really low number and it works great, so why wouldnt it work in betaflight? BTW my firmware could totally beat up your firmware :P (jk)

Best way to take care of unbalanced props is to buy a different brand of prop. At least at size 6" and below. We just break too many of them flying mini quads to spend time balancing them all. That's my opinion anyway.

Definitely! I balance the props on my larger quads cuz the props have more mass and cost more. But "F" that on these little quad props!

You seem to know a lot about PID controllers but not very much about tuning quadcopters. Are you a pilot? Why don't you spend some time learning about how the PID controller in Betaflight actually works, and then you can decide what the best way of tuning it is. The code is all up on Github for you to study. But if you don't fly, then you won't be able to actually apply any of your theoretical knowledge in a practical way. Also, have a look at my playlist, "Blackbox 101", which will show you how to get data out of the flight controller to analyze. ru-vid.com/group/PLwoDb7WF6c8l0-ABsIcnJt1FyhX9MBoVW

I am looking at Betaflight. I will look more this week end but Betaflight doesn't seem to help you with the tuning since you are still using trial and error. Are you aware of closed loop transfer functions, poles and zeros? When you change gains you change the locations of the poles and zeros in the s-domain. In your case you are changing them randomly. If you know what kind of response you want it is possible to choose the location of the poles and then calculate gains but this requires know the transfer function. It looks to me like a simple transfer function would simply require knowing the rotational inertia around each axis and the distance each rotor is from the axis of rotation so a torque around the axis can be calculated. Then calculate the PID gains. Yes, PID gains can be calculated.