Gaui gyro

[Dardoug]

I've recently got a new gaui 425 and I've put a quark gyro on it with an align ds520 tail servo but can't get the wag to stop even with taking the rates up or don an now causing a serious headache!! Also when in rate mode the servo sits centred but when go into head hold he servo travels back to a different place?! Any thoughts?

[minititinflyer]

you got sub tirm on the servos is seeing that as stick on input center the servo with out the gryo hook up to it or the rx just hook up the servo to the rx first center it then turn off it hook up the gyro back to the way it was then turn it back on hope that helps

[Dardoug]

Yeah got all sub trims at 0 centred he servo direct to the rx before connecting to the gyro but doesn't seem to make any difference!! Was working perfect when came off the trex450 that's y can't understand it! Thanks

[stark]

I don't have a wag with the quark on 425.

Did you take a look here?
http://www.spartan-rc.com/resources/...83&category=23

What is the distance of the ball on the tail servo arm? Move it inside towards the center to reduce the mechanical gain. Ideally you should have no wag at 30% gain in rate mode.

- Are the links and tail pitch assembly smooth over the entire range? In my case I had to shave off a bit of plastic from the tail pitch control lever since it was rubbing the tail hub case.
- Is the tail push-rod is straight?

cheers,

[Dardoug]

Got about 19mm from centre of ball to centre of servo. Yeah the push rod is straight and held straight through guide. Should the distance be shorter?Thanks for the link.

[PTcaflyer]

...on the 425, you should only need about 10-13mm center distance on the tail servo horn to push rod...all of mine are in that range.
PT

[stark]

DS520 is a mini sized servo. This manual recommends 8 - 15mm distance for the tail servo ball for mini sized servos on pg 42. (http://www.produktinfo.conrad.com/da...e_en_fr_nl.pdf)

13mm sounds like a safe bet to start with. Start with 30% gyro gain. You shouldn't have any wag.

Do let me know if you get any bounce on tail stops. I'm trying to fight this problem in this thread.
http://www.helifreak.com/showthread.php?t=434978

cheers,

[Dardoug]

Shifted the ball to 13mm that's the closest I can get to the centre ran a servo test and was saying wasn't centred the only was to get I centred was by putting in sub trim and since then it will go between modes without hardly any travel so is the wrong way of doing it like I say so far all seems to b working on the bench but suppose the proof is in the flight?

[Dardoug]

Just to let u no still got servo twitching with gaui with only 24% so back to the drawing board looking for vibration now start on the head!! Also going to try taking the tail ball into 10mm c how that goes failing that get the gyro checked out or possibly the tail belt being too tight was another thought orebody had but this heli was built and test flown from the manufacturer before posted out to me?Thanks.

[stark]

I don't worry much about travel while switching modes. To keep things simple avoid subtrim on the radio. Try to get 90 degrees on the servo arm as close as possible. It's OK if it is not 100% perfect. It won't result in a wag. You need to set the arm to 90 degrees with the gyro in rate mode (red light on the quark)

Do you have enough slack on the gyro cable? Leave at least 2 inches before you fasten the cable to the frame. This will ensure that vibrations don't travel to the gyro via the cables.

Just to confirm, I hope you are test flying in heading hold mode (blue light on the quark). One more thing. You must always power up the quark gyro in heading hold mode and not touch the radio sticks while it is calibrating.

By any chance are you running governor mode on your ESC? If yes, disable it till you sort out the tail wag problem.

[Dardoug]

Yeah tail servo is 90 and also the tail slider at 90 to so mechanically should be fine will look at gyro cable and try it looser c if that will help the serious servo jitter. Yeah power up in head hold and just fly in head hold. Not sure what the esc mode is fraud starting out at this hence the lack of knowledge!! Also took the swash mix down to 50% which tamed it a bit to! Does get frustrating but just persevere I know it will be worth it when get over the teething trouble!!