Cyclic gain question

[devilfish]

To tune the cyclic gain, I just fly as I normaly do, and if I se any oscillation during my normal rutine fligth I lower the gain until its gone, just as tail gain right?

But if I se oscillation AFTER stick input, like if you do hard cyclic stops etc, can that also be gain related? Or is that something else I need to tweak here. Or perhaps its a combo of both the gain and something else?

What is your method.


Thanks

[Charz]

Devilfish, if you see oscillation after stick input, that means you Bell Gains are high so you should lower them but not too much or your cyclic will feel lazy..

Dont rely on the "auto tune Bell gain" feature. When I had mine turned on, it kept increasing the bell gains that I ended up with sharp oscillation after stick input.

[georgi UK]

=] SK provide a control loop in a box, this loop has a bandwidth, to work within this the heli first needs to be mechanically tuned correctly, this will determine it's performance.

if the initial part is out this results in modifying the loop to remove unwanted effects, this is not the way to go.

I don't need to use any "after" method, just set my swash mix correctly, run a gyro gain at 45%, it's fully locked. perfectly.

[georgi UK]

Originally Posted by Charz

Devilfish, if you see oscillation after stick input, that means you Bell Gains are high so you should lower them but not too much or your cyclic will feel lazy..

Dont rely on the "auto tune Bell gain" feature. When I had mine turned on, it kept increasing the bell gains that I ended up with sharp oscillation after stick input.

=] your control rates are set too high.

[Charz]

Originally Posted by gmcallister

=] your control rates are set too high.

Not true.. My control rates where 130 and 150 and the auto tune brought the bell gains to the mid 50's after 5 flights and oscillation after stick input was quite noticable..

Regardless, one major setting that affects the abrupt spring effect after stick input is high bell gains. That is also mentioned in the manual.

[georgi UK]

Originally Posted by Charz

Not true.. My control rates where 130 and 150 and the auto tune brought the bell gains to the mid 50's after 5 flights and oscillation after stick input was quite noticable..

Regardless, one major setting that affects the abrupt spring effect after stick input is high bell gains. That is also mentioned in the manual.

=] bell gain is only for stick response, not gyro response.

[devilfish]

Originally Posted by gmcallister

=] SK provide a control loop in a box, this loop has a bandwidth, to work within this the heli first needs to be mechanically tuned correctly, this will determine it's performance.

if the initial part is out this results in modifying the loop to remove unwanted effects, this is not the way to go.

I don't need to use any "after" method, just set my swash mix correctly, run a gyro gain at 45%, it's fully locked. perfectly.

Thanks for the answer.

I understand the importance of a mechanically tuned correctly heli. I tried that with all my builds, but it will always be a compromise. Bird size, weight, servo speed, power etc etc. No setup is like the other.,

Atm Im tuning my new sk540 to make a stable hover setup in bank1.

1600rpm, scale setting, 35% expo, and CR is 130/150.
Bell gain 40/48.
Cyclic gain 50.

The heli is rock solid in the hover, i really like how the heli is feeling atm.

But I do notice a "abrupt spring effect" after fast/abrupt stick input.
Its not a problem, I mean how often will you make fast/abrupt cyclic corrections during a low rpm hover.

Im just trying to learn on whats doing what.

Cheers

[Charz]

Originally Posted by gmcallister

=] bell gain is only for stick response, not gyro response.

gmcallister, In FBL world, stick response you are refering to is also goverened by the gyro's feedback which the FBL unit uses and intermediately act to acheive and maintain the cyclic rate set by the user.

In the manual, high bell gains (relative to cyclic rates) are stated to be responsible for abrupt spring-backs after stick input which is what I understood the OP is noticing.

[georgi UK]

Originally Posted by Charz

gmcallister, In FBL world, stick response you are refering to is also goverened by the gyro's feedback which the FBL unit uses and intermediately act to acheive and maintain the cyclic rate set by the user.

In the manual, high bell gains (relative to cyclic rates) are stated to be responsible for abrupt spring-backs after stick input which is what I understood the OP is noticing.

=] it keeps changing, it started off as an "oscillation" now it's a "spring back" which one are we dealing with?

[Charz]

Originally Posted by gmcallister

=] it keeps changing, it started off as an "oscillation" now it's a "spring back" which one are we dealing with?

How about "spring-back oscillations" .
Nevermind.. I respect your opinion and aim that the OP benefits from whatever information entertained in this thread.

[devilfish]

Thanks for the feedback all.

Im sorry for my lack in the English langue. What I talk about is just what Charz is saying "abrupt spring-backs after stick input ".

Cheers