Nano CPX servos do not return to center when main rotor is running

[megasmicros]

The CPX is not a fixed pitch helicopter, the OP is describing a fixed pitch(FP) heli. On a FP the servos will remain center or near center until commanded otherwise. Once they are commanded to move they will execute the command and return to their fixed position.

This is not the case for a collective pitch(CP) helicopter like the CPX(hence the CP). In a CP heli the servos start at center and begin to adjust the pitch as soon as throttle is given(according to your pitch curve). All servos start moving up in unison adjusting the pitch and the gyro will make minor adjustments to keep it level. When you command movement it will execute and stay at the commanded position and will not return to its previous position. This gives the pilot more maneuverability and quickness, without this 3d flying would not be possible.

Once you finish your flight, land and return your throttle to 0 the servos will center within a couple of seconds. While it remains on the ground without throttle input the servos will act like a fixed pitch. They will remain in the center and if send a command they will execute and return to center. Once you give throttle those servos return to CP mode and will not return to center unless commanded to.

I hope this helps clear up the issue. If you want self-leveling servos go for a fixed pitch heli(120s maybe), much easier to fly. CP is a challenge for beginners but much more fun.

[Mojin7]

@mega. You aren't understanding the issue. I also feel you may not really understand a cp heli from what you are saying. The term self leveling and self leveling servo are getting tossed around and creating confusion. For example, "if you want self leveling servos..." Mega you are saying that with a CP heli, if you bump the cyclic forward, that the servos responsible will move in that direction and stay there even after you have stopped giving input? That is completely incorrect. If the servos responded to forward cyclic and stayed there, the heli would pitch further and further and further. One bump to the cyclic and the heli would continue to pitch further and further, or roll further and further. Not so. The attitude of the HELI stays after you stop giving input. The response of the SERVO is that it stops changing attitude of the heli once the stick gets back to center. I hope this clears thing up for you.

[megasmicros]

@mojin, I'm not saying that if you give a command to change the pitch 10% forward that it will continuously go 10% then another 10% and so on. I'm saying it will give the command and hold it there and not return the servo till it's previous position.I'm ok agreeing to disagree here I'm not one to force my view on anyone else but I'm confident I understand how a CP heli works. You can clearly see how it works, we're not talking about something that doesn't exist. We can watch and interpret it as we all see fit. I'm sure I might not use all the right words and you try and dissect them however you like, but I hope I've at least made my point and not mislead.

[Mojin7]

I hear you. However the conversation was about the servos not centering after a command has ended, not the heli. Here is what's happening...
In stable hover...
Push cyclic forward til heli is at a 10 degree angle and release. The rear servo has extended to complete the command. When cyclic is released, the rear servo should come back to end the command. The heli should stay at that 10 degrees. (More or less) The servos should stop trying to pitch the heli further. If the servo stayed in the extended position, AFTER the command has ended and the stick is centered, then the heli would continue to pitch further. So.... the servo should return to what is was doing. NOT stay where it was commanded. The heli should hold the attitude you commanded. NOT return to level flight or pitch further than commanded.

[jedibry]

Swash doesn't return to center. Any cyclic input sticks... a normal swash when functioning, the heli will drift after applying and releasing cyclic. This one is continuing that path.... sticks unless you manually attempt to recenter. Very difficult to fly. Not my first FBL either...

Anyone found an answer yet?

[hellyflyer1]

Hi All,
Its been long but I will try give an answer to this question. First of all I want to clarify that Heli Gyro/FBL system are not like quads it will not stabilize the heli after you release the inputs. I think this feature has been added to the new NCPS.
Ok going to the issue of non centering, I would recommend that you try the following and let us know if this helps

1. Try a new fully charged battery, if you have 2 then try with both batteries and see if issue is repeating. Cause in my tenure with Nano I know what a good and bad battery can do to this little heli

2. Make sure that your travel limits on TX is not set to more than required per the manual. reduce them to see if that helps

3. clean your servos.

Hope these points help, all FBL systems are unique with loads of features so you may have flown CP heli's or quads but actual CCPM system with only tail gyro gives you the real heli fyling experience.

Thanks