FBL Gyro Cgy750 - Pitch Precomp

[Erfan]

Hi guys

On Cgy750, were could I find the pitch precompensation setting? That is the setting to change when the nose goes left on hard up/down pitch?
In 3GX and brain/ikon its called pitch precompensation, cannot find that on the cgy750.

I could find something called "F/F mixing" under the "Rud Gyroi Expert" menu, which could be set to on/off and when set to "on" you could set something called "F/F mixing rate" You seem to be able to give it more +% or -%.
Is that it or am I looking at the wrong place?

I need to stop the left nose on hard pitch movements, if the above setting is correct, are we then talking about more at the + or more - ?

 

[Lee]

I don't have this gyro, but i did just look over the manual page 96. So this is my educated guess

Make sure we are talking about the same thing.
"Hard up and down Pitch"
Are you changing the Collective, or the Pitch hard up and down?

In the CGY750.
You will need to adjust the F/F (feed forward)
Menu is the Acceleration gain (ACC Gain)

If everything in your heli is set mechanically correct, and the tail gain is at its highest stable value, then you can try adjusting the ACC Gain.
If the heli turns left, you should need to increase the gain.
If it turns right, decrease.

 

[Erfan]

Page 96? My manual only has 26 pages total
Cgy750 v1.4 manual.

I mean the pitch that takes the heli up and down in the sky, not sure if there is another word for it besides pitch? I think its called collective pitch, when all servo horns move up or down.

I found the menu you mentioned, under RUD gyro expert. I will try to play some with the ACC gain, not sure if I have to turn the F/F mix on or not before ACC gain does anything.
And perhaps something needs to be changed under F/F rate as well since it has to do with F/F mix.

At least it feels like I'm most likely looking at the correct menu items.

 

[Erfan]

I activated F/F mix and tried in " F/F rate" values from +10 to +75 with no luck, the tail still kicks.
I also tried ACC gain from 10 to 50%.
Non of the above seemed to do much difference.

The F/F rate has not much more to give, I will try to go up all the way to +100 tomorrow and see if that would help. The same with ACC gain which goes up to 200%.
I will also try goig negative on F/F rate, I tried a bit today but it seemed to make it worse, need to try some more, could have been mistaking, just tried -15.

But I'm pretty sure it is the correct menu items because I can see the tail change pitch when going from midstick to high and low and collective pitch, it did not do that before so I'm pretty sure I have found the correct menu for it.


Does anybody have any other suggestions to counter tail kicks?
I use gov, castle own gov. And when I had 3gx with some pitch precomp it did not do this. Nothing besides the gyro has been changed.

 

[holtneil]

Hi mate Lee is right on that adjustment , but the tail has to be right to start off, if you hover in rate mode does the tail drift, if it does you need to adjust the servo rod to get it to hover with no drift,this will help the gyro with pre comp
What is the F/F mixing acceleration gain set at it may not be working fast enough page 21 part 17

 

[Erfan]

I never did a "trim flight" as the cgy750 manual suggests, it had no drifting so I never did that part but I will try and see if the tail holds in rate mode.
I know I have some tail pitch at neutral stick as suggested in the trex600 manual. But not sure if its enough for the cgy750, will try in rate mode and see how it holds.

ACC gain is set to 50%, I will try to get that up as well, try to increase it 10% at the time and see if it helps, it goes up to 200% so there is still a lot left.

 

[holtneil]

Hi mate I am sure its just a fine tuning problem then it will hold under hard pitch pumps

 

[Lee]

Tail pitch at neutral for the 600 should be about 8º pitch between the two tail blades if folded over.
As I, and Holtneil said, make sure to get the bird mechanically tuned first, before messing with settings.
Butter smooth mechanically from tail servo to tail blades, no binding and no slop.
Tuning flight to get correct tail pitch for stable hover. ( as mentioned, about 8º pitch)
Tail gain adjusted to highest level before wagging starts.

Then you can try messing with the ACC gains etc.
Good luck