Micro tuning techniques - different than larger quads


#21

Let’s say I set up my PIDs the way I like it with say a set of 15000 kv motors, and then I decide to swap out the motors for a set of dark edition 18000kv, would that require a PID readjustment?


#22

I’ve found not much if any at all in my experience if it’s a good tune to start with for a brushed copter. Maybe just an adjustment to tpa, hoverpoint, and throttle expo if you use those things. What usually does require a big pid adjustment is different size props.


55mm prop to 65mm prop - Retune?
#23

@NotFastEnuf what affect does TPA have? What do I need to look for when adjusting TPA? Thanks


#24

TPA lowers your pids by up to the percentage you select as you approach full throttle. As I understand it, it starts to happen above the throttle breakout point that you set. That midpoint is also where throttle expo is applied. So if you are tuned to use those things and you put in stronger motors … your actual hoverpoint lowers and your expo may be in the wrong place and your tpa may be activating late. That would look like a mid throttle oscillation that goes away with more throttle IF you are using it and tuned up to take advantage of it. Think of it like mechanical spark advance on on old car distributor ( only we retard with increased rpms instead of advance). Throttle expo in the wrong place would feel like you have to correct too much to stabilize altitude. Does that help?


#25

@notfastenuf thank you for going in depth and teaching so much in this thread… I keep thinking I have my tune right, and then I find something else that needs to be tuned in or out… So I’d take a break, check back on the advice on this thread, and then I get re-inspired to try something new with your advice.

I have been working my first tune ever, and man I put a set of cheaper motors through the ringer doing it. lol (Crashing too much trying to figure out the balance between P and D for flips and rolls and flying them waaayyyy too hard on the wrong settings, getting them way too hot etc…)

For some reason tho whenever I throttle up it tends to yaw tho which is annoying… I can’t tell if that is just part of the tune or if it is because I accidentally slightly crashed into a wall and possibly damaged a motor, but as each day passes, I get closer to my perfect tune!

Thanks again man.


#26

Quick yaw movements to either side will show an arm dip very briefly with a weak motor. Yaw authority is where we push the motors of a quad to the max - and a weak motor will show itself there. If it stays flat in the first split second of a hard yaw at hover (assuming you have very high yaw rates that are indeed pushing max) then a motor is not your problem and you need more yaw I. The yaw gyro see that error - no doubt - but it can only push as hard to correct it as you allow with its value. The other thing that could be is your sticks on your TX - make sure it is not (or you are not) commanding yaw movement as you raise the throttle. Watch your receiver tab in the configurator to check that on the bench (be safe - no need to run motors). If yaw channel is moving there cause of human error or mechanical error on your tx - add a yaw deadband to tell the fc to ignore that first bit of commanded movement. I personally cannot throttle up without changing yaw a little - I correct my human error with deadband.

Curious - are you making adjustments from the stock tune as you go - or have you tried the tune from scratch complete work up?


#27

I really really don’t know how to tune, but this video helped me to get my micro brushless tamed, and what I think is a good tune (if any of you guys touch them might yhink is crap). What do you guys think of his style of tune, good, bad, maybe any imput might help my tuning process. https://youtu.be/ehyXLsvaEhw


#28

That’s basically the same from scratch method I talked about earlier. But the kind of signs and sounds he is looking for in setting P are more specific to high power brushless quads with active braking. For a micro brushed - your p oscillations after sharp movement won’t be that crisp.

I give it a big thumbs up.

Just to add - motor temp and d values are also specific to active braking brushless setups. Don’t be afraid to add d in your brushed copter to get a buttersilk smooth feeling. I think I have values as high as 60 in some. Hahaha


#29

right on man. I think it may be the weak motor if anything - I thought maybe it was the human error as well with the yaw upon throttling, but i noticed even with small throttle punches and just throttle raises it tends to do it as well… It’s definitely a dip in the front right arm i think - causing it to act super sluggish…

I noticed with a brushed quadcopter the motors cant stand yaw like brushless lmao

I will keep the deadband in mind though in case it actually is me… and when I get some more free time I will check in the RX tab to see if its human error JIC

As much as I know that starting a tune from stock is 4 timers better of a result in the end, I just tried to tune this time based off a stock betaflight tune - It’s my weekend starting 2night so I wanted to try to get some air time in after stressing about all of this PIDs business this week…

I learned a lot tho thats for sure!

with the DX6 its not as easy to assign a value to the switch, so I’ve been having to plug in, make small adjustments, unplug, test flight, plug in, make small adjustments, unplug, test flight -repeat repeat repeat!!! lmao takes forever, lol I also feel like my USBs are wearing away haha


#30

Yeah - sounds like a motor. Go fly and have fun. Like I said before -
tune both ways and compare! There is always time for scratch later - go
burn that motor the rest of the way out! Waste of time anyway from scratch
with a weak motor. You’ll get close but won’t nail it. Remember you have
three profiles to save pids on. So one for tune of stock. One for
scratch, and one to try combos!


#31

Excellent, the way he explained it sounded to easy, also am on a couple brushless micros.
Thanks NotFastEnuf


#32

Thanks again for all the help man! I definitely will rip it at the park 2moro, and I will certainly fly a battery in honor of @NotFastEnuf ! I Hope you are getting in as much flight time in as you require to fulfill your lifestyle!

Edit: also thank you for reminding me of all 3 pid profiles. I will absolutely look into that


#33

Thanks man. I have a 2 year old and a 4 month old. So my flight time is currently a trade off for missing sleep between 12 and 2am ( thank god for the whoops). But I’d rather be tired and happy than…
Recently the whoop canopy project has put a dent into it but building/designing is restorative and relaxing too. I burnt my 8.5mm motors months ago and have yet to put the spare set in, and I have a 3" brushless that’s still in pieces on the bench for a weight watchers revision since before my second son was born. That’s the last thing I tuned about 5 months ago. I guess I miss it so I’m talking a lot about it to cope. Hahaha. Have a great flight! Post vid back here if you can so we can see your current tune.


#34

@Airkaos - if you are getting ready to tune brushless - it will sound more like that video than brushed does. The words I used to describe the feel in my account of the method still apply. Just to remind you - you will need to keep d low if you have “damped light” active braking - but it won’t need much to smooth out so take small steps and keep an eye on motor temps. Pay attention to your baseline temp with d at 5 or below for comparison while you tune up P. Let us know how it goes.


#35

A lot of the new fc’s for micros are coming with flash these days. I think black box is useful for both brushed and brushless - should we start a blackbox log review thread? I’m still an unknown time off from my next build/tune where I could post logs - but I’d enjoy reviewing stuff others post Bardwell style. Lol. I’m sure there are others here too!


#36

Got to thinking about this more and comparing my method to stingy in the video. There is one major difference (other than the obvious that I wipe one axis at a time). He zero’s I and D vs. I drop to super low values but not zero (I=10, D=5). That is actually a big difference and here is why:

Having just a touch of I and D serves two purposes over zero (For me)

  1. Much easier to control the craft.
  2. The transition into the ‘sweet spot’ for adjusting P will be more obvious. I tried with zero I & D, and it just seems like a smooth progression of wobbles as P increases - with just a touch instead - you will go from sluggish - to sweetspot crisp with little wobbles (like stingy video) - to nervous wobbles that make you feel like it’s gonna go out of control.

Try it both ways… see if you agree.
Remember - you’ve already got your rates and expos that you like loaded up. So essentially the rest of the tuning process after P does two things - removes the little wobble after the sharp test motions - and makes it hold the commanded angle when you fly around. 90% of the feel of your finished tune is gonna come from the P adjustment. So finding the sweet spot is simple - just pick what feels right to you.


#37

Thank you so much for this. I have a couple of brushed minis with Scisky boards (90mm and 120mm), and the tuning is killing me. I’m hoping to learn to fly acro on these (I’m flying Tiny Whoops and E010s FPV, and am addicted to angle mode, sadly), but right now it’s like mush.

To be clear, if I want to put the training wheels back on and fly angle/horizon, the PIDs from acro mode still apply, with the leveling strength/angle modifying it?


#38

Yep you got it. Practice hover in acro first and the sharp left/right & forward/back motions before you go to tune. You’re going to have to tune acro starting with a really sloppy quad when you lower values. Not a great time to learn!


#39

Yes, practice hovering first in acro, controlling the natural drift acro mode can have… throttle up and hover, if it starts drifting to the right, gently push left and “level it out” manually. i like to use an “X” to mark the hover spot, and I try to hover over the X…

Once you feel comfortable hovering, practice moving forward by gently pushing forward… when you want the quad to stop moving forward, gently push back to stop it. If you don’t push back to “level it out” it’ll just keep going forward. If you push back too much it may crash, so be gentle with the stick movements at first…

Remember with acro mode, for every action you give it, there needs to be an opposite reaction to level it out if that makes sense… unlike angle mode, there is no computer to “self level” the quad. It is up to the pilot to keep things under control :slight_smile:


#40

if you are trying to tune the sci-sky v1.2 then i feel your pain.
please try another board for beginning tuning and acro learning… (i even like the NQX better for learning)
I gave all my v1.2s away.
They were so discouraging for a new tuner.
The v1.2 is the worst board I’ve tuned and flown.
The v1 is amazing in comparison to its ease of tuning.
I would personally never recomend to learn to tune on a v1.2 as it seems nothing like any other i have tried to make fly decently.
Once you become a tuning ace then go back to the v1.2 for a challenge.
Getting it to have the correct balance of smooth center/mid to tight flip outer stick is mind numbing (for the new tuner).

(disclaimer)
it seems its just me that feels this way.
i see things differently at times.