jcg1541

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Re: CC3D on Fixed Pitch Helis
« Reply #15 on: February 07, 2018, 04:01:10 am »
Here at LP, toilet bowl usually describes a GPS problem with Revo class FC's.

Since you are using CC3D, it is probably just a PID issue.  PIDs are too high.  Are you in Rate mode or Attitude?
Good assessment. The whirling is basically just oscillation by engineering terms, and it usually takes some gain to get an oscillation.
I am in attitude mode. I use CC3D atom. I am a beginner heli pilot. My toilet bowl effect looks awfully similar to quadcopters toilet bowl effect that I see on youtube. The oscillation period is about 3 seconds, and the flushing action is harrowing. I have to yank it hard to get it out, or it will crash within 10 seconds.

jcg1541

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Re: CC3D on Fixed Pitch Helis
« Reply #16 on: February 07, 2018, 04:05:04 am »
Thanks Dave will give it a try, it's been at 0.006 but will experiment with some different values.

Have to say I'm scratching my head a bit over the setup. Had been slowly increasing P settings but continue to get this low frequency oscillation (like 1-2 seconds frequency) that's worse on pitch. If I leave it the oscillation continues to get worse and I think if left would result in a crash. I would have assumed when I've tried high P's (and I've gone as high as .006 on Pitch P) it should have been such a strong stabilising force that the heli attitude would have been relatively locked, or had a high frequency oscillation. Tried high I's and even a range of D's....

Fingers crossed the Gyro tau helps...

I also hate the default Tau that immediately returns the servo back to neutral, like it isn't sure that it is doing the right thing. Looks very timid. 

karla

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Re: CC3D on Fixed Pitch Helis
« Reply #17 on: February 07, 2018, 02:52:15 pm »
Hi jcg1541,

I also hate the default Tau that immediately returns the servo back to neutral, like it isn't sure that it is doing the right thing. Looks very timid.

I luckily never had a need to tamper with the GyroTau setting, but noticed the default setting in Next is 0.003 and not 0.006.
Is this working for you?

Re: CC3D on Fixed Pitch Helis
« Reply #18 on: February 08, 2018, 12:40:13 am »
Gyro Tau is simply a vibration filter and should have nothing to do with it returning the servo back to neutral.

Leave it at default unless you have big vibrations that can't be fixed by carefully balancing things.

jcg1541

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Re: CC3D on Fixed Pitch Helis
« Reply #19 on: February 08, 2018, 01:46:15 am »
Changing the Gyro Tau has definitely helped. Dropped it back to 0.03 with some more moderate cyclic P gains and there was definitely an improvement, better with higher gains. Shot this video on second flight yesterday trialling some higher P settings and had a half decent flight. Definitely moving in the right direction now thanks  8)

Same experience here. Gyro Tau need not changing. Just increase Attitude P gain is enough for big improvement. I changed it from default 25 to 64, and , WOW, I am hovering my blade 230s  in my hotel room!!

jcg1541

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Re: CC3D on Fixed Pitch Helis
« Reply #20 on: February 08, 2018, 01:53:48 am »
Hi jcg1541,

I luckily never had a need to tamper with the GyroTau setting, but noticed the default setting in Next is 0.003 and not 0.006.
Is this working for you?

Karla, I am hovering my blade 230s in my hotel room now with the default GyroTau 0.003 , and changed cyclic pitch/roll P gain from default 25 to 64. I am using Ubuntu's default repository of LibrePilot, which is 16.09+dirty. So, I got the default gyrotau 0.003 . Loooove it.  WOW. My blade 230s has an onboard raspberry pi zero with MQTT software. Picture of my setup is at https://nocomputerbutphone.blogspot.com/2017/12/converged-drone-developers-platform.html

jcg1541

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Re: CC3D on Fixed Pitch Helis
« Reply #21 on: February 08, 2018, 02:12:27 am »
Gyro Tau is simply a vibration filter and should have nothing to do with it returning the servo back to neutral.

Leave it at default unless you have big vibrations that can't be fixed by carefully balancing things.
Yes Sir, You are correct. I am using the default Tau now. The returning of servo arm was caused by low P gain.

karla

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Re: CC3D on Fixed Pitch Helis
« Reply #22 on: February 09, 2018, 01:31:56 am »
I am hovering my blade 230s in my hotel room now with the default GyroTau 0.003 , and changed cyclic pitch/roll P gain from default 25 to 64.
:) Great to hear it worked out.
Thanks for the link, thats a very cool build.

Re: CC3D on Fixed Pitch Helis
« Reply #23 on: February 22, 2018, 03:57:36 am »
Haven't logged in here for ages so nice to see posts.  8)

I did a lot of playing with gyro tau, thrust scaling plus using different servos in order to get rid of the cyclic shakes on my FP build. It flies pretty nicely now in Rate, very nicely in Attitude but not what I'd call perfectly. The thrust scaling was crucial though with reduced P's and I's at higher throttle settings for both Roll and Pitch. Increasing the gyro tau just resulted in lower precision (controls felt sloppy).

Currently doing a CP build on a V950 but yet to maiden it...

Re: CC3D on Fixed Pitch Helis
« Reply #24 on: February 22, 2018, 04:08:23 am »
Current fixed pitch .UAV file....

Last video shot;