FC + ESC = mamba f405 stack MK2
motors = t-motors f60 III 2750kv

My motors were getting really hot with the default BF 4.2.2 pids,
I watched about 2-3 hours worth of tutorials about PID tuning and spent around 1-1.5 hours to try to change some things, because in addition to
the hot motors, my quad didn't feel good at all, and it shook from the moment I hit arm.
I ended up with these PID settings:


this is the sweet spot for me not getting hot motors(they are still hot but not as much as before) and an OK tune, but I still need to up my P gain, but I am unable because of the motors getting very hot when I hit 20 or above in the D gain territory.

another thing, about the quad making sounds and shaking a bit(sometimes taking off because of that) at the moment I arm, I applied a bit more filtering:


and it seemed like it did the trick, if I try to put it at 0.85 the quad starts shaking again so that's the minimum I can get away with.

is there anything more I can do to reduce my motors from getting so hot?
probably something with filters I guess? is it normal for motors to get hot at low D gains?

I tried searching for more info about it, I also watches JB's video about hot motors:

but thankfully I didn't have this kind of issue

Can't see the pics. What voltage lipo and whats the pitch and roll P and D? (D Min and D Max if applicable)

(12-Sep-2020, 05:26 PM)the.ronin Wrote: Can't see the pics.  What voltage lipo and whats the pitch and roll P and D?  (D Min and D Max if applicable)

I've re-uploaded to a different site, I'm using a 4s battery.

I tried using bi-directional D-shot, I flashed my ESCs with blheli_s 3.73 and enabled everything according to JB's guide,
I set my filters and PIDs sliders back to default and it made 0 change,
I set my filters to 0.7 on gyro and D-gain, and set my PIDs to:
ROLL P - 30
ROLL I - 40
ROLL D - 10
PITCH P - 30
PITCH I - 40
PITCH D - 10

YAW P - 40
YAW I - 65
YAW D - 0

with that tune I don't get hot motors, and I have a 'decent' tune, I don't know how I get away with such a low D gain but yeah.

(12-Sep-2020, 05:55 PM)SaHaRzZz Wrote: I've re-uploaded to a different site, I'm using a 4s battery.

I tried using bi-directional D-shot, I flashed my ESCs with blheli_s 3.73 and enabled everything according to JB's guide,
I set my filters and PIDs sliders back to default and it made 0 change,
I set my filters to 0.7 on gyro and D-gain, and set my PIDs to:
ROLL P - 30
ROLL I - 40
ROLL D - 10
PITCH P - 30
PITCH I - 40
PITCH D - 10

YAW P - 40
YAW I - 65
YAW D - 0

with that tune I don't get hot motors, and I have a 'decent' tune, I don't know how I get away with such a low D gain but yeah.

If you get a decent tune from these PIDS then leave it that way. If your motors are not hot after this then ur good.... All quads are different, on my 3 inch quad I have D set to something like 16 or 17... and on other quads I've seen as much as 50 D (which is kinda crazy lol).

D is what fixes any errors the gyro reads AFTER the fact... so on smaller quads (and I'm just using logic here and guessing) one would assume you wouldn't need as much D ANYWAY...... On a 7 inch quad after a flip there is a lot more inertia in which the D term has to help fight against.....  (Again, this is just an off the cuff assumption I'm making, but it sounds legit right ;D lol)

Seriously though if ur quad flies good then leave it...... Maybe turn down the filtering to make it even better (turn down the filtering as in raise the sliders to right).

Yea those are crazy low Ds. And that leaves your P at 3x D which is surprising your quad isn't shuddering like crazy on turns. For 4S your D's should generally be in the 40-50 range with P's about 1.5-2x that given proper filtering.

Please don't take offense to my frankness, but what you are referring to as a "decent" tune is likely a "least worst" tune given your settings.

I am not familiar with the default filtering settings since I just override them but why is the Gyro Notch Filters all off? You have RPM Filtering (Bidirectional Dshot) and Dynamic Filter turned on in the Config tab?

(12-Sep-2020, 07:02 PM)the.ronin Wrote: Yea those are crazy low Ds.  And that leaves your P at 3x D which is surprising your quad isn't shuddering like crazy on turns.  For 4S your D's should generally be in the 40-50 range with P's about 1.5-2x that given proper filtering.

Please don't take offense to my frankness, but what you are referring to as a "decent" tune is likely a "least worst" tune given your settings.

I am not familiar with the default filtering settings since I just override them but why is the Gyro Notch Filters all off?  You have RPM Filtering (Bidirectional Dshot) and Dynamic Filter turned on in the Config tab?

aww... My D's are in the teens in this video:



I think this tune is pretty damn tight! 40-50's in D term seems really really high.

Don't get me wrong. Low PIDs can still fly good. I'm just saying it can fly better.

"High" is very relative.

This is the filtering on my Acrobrat Duo on 4S:



And here is how it flies:




[edit]

I almost forgot the punchline lol:

(12-Sep-2020, 07:20 PM)the.ronin Wrote: Don't get me wrong.  Low PIDs can still fly good.  I'm just saying it can fly better.

To get my 5 inch to fly good all the PIDs needed to be much higher...... when I first started trying to tune my first 5 inch it changed my whole outlook on tuning kinda...... I was always thinking... MORE D!????

(12-Sep-2020, 06:08 PM)bLoWsMokE Wrote: If you get a decent tune from these PIDS then leave it that way. If your motors are not hot after this then ur good.... All quads are different, on my 3 inch quad I have D set to something like 16 or 17... and on other quads I've seen as much as 50 D (which is kinda crazy lol).

D is what fixes any errors the gyro reads AFTER the fact... so on smaller quads (and I'm just using logic here and guessing) one would assume you wouldn't need as much D ANYWAY...... On a 7 inch quad after a flip there is a lot more inertia in which the D term has to help fight against.....  (Again, this is just an off the cuff assumption I'm making, but it sounds legit right ;D lol)

Seriously though if ur quad flies good then leave it...... Maybe turn down the filtering to make it even better (turn down the filtering as in raise the sliders to right).

It's a 5 inch quad, but it doesn't fly that good, it's decent to what I flew before but it's not good, it's twitching and stuff.
As for turning down the filtering, if I do it my quad is making weird sounds when I'm arming and in the air, if I take it to defaults(1.0 on both) it can randomly take-off on arm.

(12-Sep-2020, 07:02 PM)the.ronin Wrote: Yea those are crazy low Ds. And that leaves your P at 3x D which is surprising your quad isn't shuddering like crazy on turns. For 4S your D's should generally be in the 40-50 range with P's about 1.5-2x that given proper filtering.

Please don't take offense to my frankness, but what you are referring to as a "decent" tune is likely a "least worst" tune given your settings.

I am not familiar with the default filtering settings since I just override them but why is the Gyro Notch Filters all off? You have RPM Filtering (Bidirectional Dshot) and Dynamic Filter turned on in the Config tab?

it's doing bad, and yeah I know these are very low D's,
I am referring to it as the least worst tune I have, mostly because it doesn't fry my motors.

I have Bidirectional Dshot enabled in the configuration tab, but is there a 'Dynamic Filtering' option in there?
I followed JB's guide on it(he released a guide for 4.1)

I wish I could up the D gain but my motors are getting really hot

You probably already have it enabled but just in case it's located here on the Config tab:



Also it's likely right but just make sure your magnet count is right for RPM filtering (usually 14 if it's a standard 22xx type motor for 5").

(12-Sep-2020, 08:50 PM)the.ronin Wrote: You probably already have it enabled but just in case it's located here on the Config tab:



Also it's likely right but just make sure your magnet count is right for RPM filtering (usually 14 if it's a standard 22xx type motor for 5").

Yeah It's enabled, and my magnet count is set correctly, I've manually counted the magnets

Then you might have some serious mechanical noise issues. Loose mounting, loose antenna, anything that might cause vibrations which then gets amplified by your D.

I'd also try and reset your filters. I'm hard pressed to believe that gyro notch filtering is off by default.

(12-Sep-2020, 09:56 PM)the.ronin Wrote: Then you might have some serious mechanical noise issues.  Loose mounting, loose antenna, anything that might cause vibrations which then gets amplified by your D.  

I'd also try and reset your filters.  I'm hard pressed to believe that gyro notch filtering is off by default.

The mounting and the antenna(which is brand new because I suspected it might have been it, TBS TRIUMPH now) are sturdy and not loose at all.

BTW my pids and filters are looking like this:

two days ago I hit 'Reset all profile values' in case something like disabled features is making these issues, I think Gyro Notch Filtering is off by default because I didn't turn it off.
Should it be on?

Try reseting just the filtering again makes sure you have a good starting point. Also take a real good look at the motor mounting make sure screws or anything else are not touching the windings. Other than that, the only real explanation is noise on your craft - or a faulty FC.

Hmm Mamba. Not the most reliable but personally, I've had a few that flew fine.

(12-Sep-2020, 08:15 PM)SaHaRzZz Wrote: It's a 5 inch quad, but it doesn't fly that good, it's decent to what I flew before but it's not good, it's twitching and stuff.
As for turning down the filtering, if I do it my quad is making weird sounds when I'm arming and in the air, if I take it to defaults(1.0 on both) it can randomly take-off on arm.


it's doing bad, and yeah I know these are very low D's,
I am referring to it as the least worst tune I have, mostly because it doesn't fry my motors.

I have Bidirectional Dshot enabled in the configuration tab, but is there a 'Dynamic Filtering' option in there?
I followed JB's guide on it(he released a guide for 4.1)

I wish I could up the D gain but my motors are getting really hot

I have similar issues with my 5 inch....... it just flies weird..... I found out that lowering the I to like the mid 30's helped for me..... The only thing I can't get rid of now is a dip when i cut the throttle fast after a punch out...... Nothing I do can get rid of that. I fear this FC's software is wonky because for one betaflight alerted me saying that I had to use a custom file or the thing wouldn't work.... sure enough I said no and betaflight didn't even register the gyro. I ended up having to get it though.I don't like putting D term much higher than 34. I try and use the safest route possible in anticipation of a crash (or many) ;D