Oxy 2 speed wobbles

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itsmillertime
Posts: 13
Joined: Tue 18. Jul 2017 1:24:16

New to the Spirit fbl and not sure how to tune this out. I did not have this issue with the micro brain fbl unit I previously had on it but after a crash I added a stretch kit and noticed a slight cyclic wobble and slow tail wag in a hover. After installing the micro spirit it is solid in a hover and while doing 3d but shakes badly only during fast flight. Fast forward flight it seems the aileron and elevator axis is affected but fast reverse flight is mostly just aileron axis.
ZeXx86
Site Admin
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Hello,

please check if the value of Advanced/Geometry 6° was configured precisely.
If yes, make sure that when Servos/Subtrim (tuning) is enabled, then both blades are exactly in the same level (when you fold ends together).

Also make sure that the servo frequencies are correct. If they are e.g. at 50Hz performance will be much worse.

You can share your settings here:
http://4dsviewer.spirit-system.com
Spirit System developer
itsmillertime
Posts: 13
Joined: Tue 18. Jul 2017 1:24:16

ZeXx86 wrote:Hello,

please check if the value of Advanced/Geometry 6° was configured precisely.
If yes, make sure that when Servos/Subtrim (tuning) is enabled, then both blades are exactly in the same level (when you fold ends together).

Also make sure that the servo frequencies are correct. If they are e.g. at 50Hz performance will be much worse.

You can share your settings here:
http://4dsviewer.spirit-system.com
http://4dsviewer.spirit-system.com/www/ ... eli-2.4.1)
ZeXx86
Site Admin
Posts: 12836
Joined: Mon 29. Apr 2013 16:06:44
Contact:

Thank you!

To solve tail wag I recommend to decrease pirouette consistency to 160.

It is also possible that such rudder issues transfered to the cyclic.

What servos do you have?
Servo frequency could be too high. Usually 200hz for cyclic is fine.

Also I recommend to reduce Elevator filter to 1 - 2.
Spirit System developer
itsmillertime
Posts: 13
Joined: Tue 18. Jul 2017 1:24:16

ZeXx86 wrote:Thank you!

To solve tail wag I recommend to decrease pirouette consistency to 160.

It is also possible that such rudder issues transfered to the cyclic.

What servos do you have?
Servo frequency could be too high. Usually 200hz for cyclic is fine.

Also I recommend to reduce Elevator filter to 1 - 2.
Piro consistency was 160, I raised it because stops felt mushy. Lynx servos for the oxy 2 - 333Hz, tried from 50-333Hz, no difference. Elevator filter was 1, raised it while testing various settings.
ZeXx86
Site Admin
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Joined: Mon 29. Apr 2013 16:06:44
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Here we have cyclic lynx servos too on the oxy 2 at 200hz.
It is working pretty well with zero wobble, stock setup.

You can check our settings in the Settings section.

Did you used supplied double sided tape? Is the unit mounted firmly?

To fix stopping you can use Rudder dynamic. We have it increased.
Spirit System developer
itsmillertime
Posts: 13
Joined: Tue 18. Jul 2017 1:24:16

ZeXx86 wrote:Here we have cyclic lynx servos too on the oxy 2 at 200hz.
It is working pretty well with zero wobble, stock setup.

You can check our settings in the Settings section.

Did you used supplied double sided tape? Is the unit mounted firmly?

To fix stopping you can use Rudder dynamic. We have it increased.
Yes, used supplied mounting tape and it is mounted firmly. I'll reduce frequency to 200 again and compare to your settings.
ZeXx86
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Joined: Mon 29. Apr 2013 16:06:44
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Great, also make sure that the blades are not tight in the blade holders. This could cause various issues.
Spirit System developer
itsmillertime
Posts: 13
Joined: Tue 18. Jul 2017 1:24:16

The changes I made yesterday make it fly better but the issue is still there and now it pitches up hard with even the slightest touch of down elevator while in fast forward flight. I increased pitch as well and the 350g 210mm bladed Oxy2 with a 3900kv 250 motor on 4s 850's is just insanely fast now, lol.
ZeXx86
Site Admin
Posts: 12836
Joined: Mon 29. Apr 2013 16:06:44
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If it is pitching up abruptly it mean that there is no required range for elevator to compensate.

The higher collective pitch, more range you will need and more demand is putted on the rudder and motor.

So the only solution is to increase cyclic ring range if mechanics allow it in all positions.
If not, then collective pitch range must be lowered.

So it is result of increasing collective pitch, since in fff some forces must ve compensated. Especially if CG is not perfect, more compensation/travel is required.
Spirit System developer
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