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dual rate (dx9) and servo traveling range problem
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Author:  riodoro86 [ Wed 12. Aug 2015 7:54:11 ]
Post subject:  dual rate (dx9) and servo traveling range problem

Hi everybody,

i have some problems in understanding the dual rate function and also about the traveling range of servos. Let me explain to you where my doubts are coming from...
Yesterday i wanted to add some dual rate (dx9) because my quite new goblin 380 was to fast and agile for me. The interesting thing was that i had to reduce dual rate down to 30% to see some effect (dx9 dual rate is from 0% - 125%). Of course now my first thought was that i configured something wrong in the spirit regarding servo travelling and so on.

Now i checked the settings:

In the diagnostic tab everything seems to be ok. Aileron and elevator are at 0% and at maximum stick movement at -100% and 100%. But after some tests i had the strong suspicion that for roll and nick the maximum movement of my swash plate was reached at maybe 2/3 of stick movement. which means the last 1/3 of stick movement the swash plate would be already on its maximum (which would explain my fast and agil goblin^^).

Proving my suspicion:

To do that i went to "limits" and activated "cyclig ring (tuning)" to deactivate the stabilisation. I did 0% pitch and tested my roll and nick. And it was as i expected. After 2/3 of stick movement the swash plate was at maximum deflection (The cyclig ring (tuning) setting itself is configured correct, so no problem there).
What i did now is reducing the servo traveling range at the transmitter(dx9) for roll and nick i had to reduce it from 100 to 63 to have maximum swash plate deflection at maximum stick movement. So far so good but of course now in the diagnostick tab i have only 63% at maximum stick movement which is not the recommended value refering to the manual.....

So what i need now is some explanation..... is it ok what i did? is it normal behavior? alternative solution?

Thank you very much :D

Author:  ZeXx86 [ Wed 12. Aug 2015 8:04:54 ]
Post subject:  Re: dual rate (dx9) and servo traveling range problem

The behavior you are describing is normal with Flybarless systems. You should not use Dual Rate for this purpose at all.
On the ground swashplate is behaving differently than in the air, because there is no feedback (movement) from the helicopter at the time you are moving with the sticks.

So you should return DR value back. If your helicopter is rotating too fast in the air, you should decrease value Rotation speed in the Sensor tab. You should never increase it more than you really need.

Author:  riodoro86 [ Wed 12. Aug 2015 8:39:16 ]
Post subject:  Re: dual rate (dx9) and servo traveling range problem

ok, behavior on the ground is different, that's clear. But that's why I moved to "cyclig ring (tuning)" to deactivate the stabilisation. And for me it seems that the stabilisation is deactivated in this setting (maybe I'm wrong)and the stick movement directly correspondents to the servos. This is where I encountered the "problem" that maximum servo movement is only 2/3 of stick movement. This is where i reduced the servo traveling range (not dual rate) to compensate it. And it was necessary to go from 100 to 63. So the question is, is it normal that i have at activate cycling ring setting 100% swashplate deflection at 2/3 stick movement.... sorry it is a bit hard for me to explain..

Thanks a lot!

Author:  ZeXx86 [ Wed 12. Aug 2015 8:47:31 ]
Post subject:  Re: dual rate (dx9) and servo traveling range problem

Yes, it is very correct.

It is behaving in this way to check if there is any mechanical binding with servos more easily.
You should configure Aileron / Elevator range as high as possible.

Author:  riodoro86 [ Wed 12. Aug 2015 9:05:00 ]
Post subject:  Re: dual rate (dx9) and servo traveling range problem

ok, so maximum deflection of the swashplate at only 60% of stick movement is ok inside this setting. I should not try to get 100% swashplate defelction at 100% stick movement by modifing "travel adjust" values at my dx9 ( i looked the correct word up in the manual^^)?

sorry that i ask so much so often but i want to be sure.

thanks for your help and time!

Author:  ZeXx86 [ Wed 12. Aug 2015 9:11:29 ]
Post subject:  Re: dual rate (dx9) and servo traveling range problem

Yes, you do not have to do any additional correction in your transmitter. Everything is OK.

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