HDX500SE V1 tail wobble

[Heli Paramedic]

Hi fellow freaks,

Can anyone help me out with a fix to a tail wobble.

After a recent crash and rebuild, my tail has developed a wobble I can't seem to get rid of. the best way to describe it is a slight side to side (about a quarter inch) movement of the tail at a rate of about 2 to 3 times per second. Seems to be more pronounced when hovering. Can't tell when in forward flight.

Heres what I've done to try and fix it:

Repaced spindle, main shaft, main blades and flybar
Replaced boom, boom supports, belt, tail shaft and blades
Replaced CNC tail case with plastic SA tail case

Belt tension perfect
Gyro gain (GY401 + 9254) adjusted up and down - makes no difference
No binding anywhere in tail

Any suggestions?:arggg:

[LITHIUMSTATIC]

Head Dampeners? What head speed you running at?

[Heli Paramedic]

Thanks Jeremy,

Head dampers are new. Not sure about head speed as I dont have a tach.

If this helps I have a 1050kv motor with 19T pinion on 4S Lipo & stock 94T main gear

Normal TC 0, INH, 75, INH, 100
Idle 1 80, 80, 80, 80, 80
Idle2 95, 95, 95, 95, 95

thanks,

Nathan.

[Heli Paramedic]

Also tail wobble seems very different from the wobble you get with low a headspeed.

[Heli Paramedic]

I guess it's more of a tail wag than a wobble. i've tried reducing gyro gain but that has no effect????

[LITHIUMSTATIC]

Your main blades to tight? They may not be straightening out completely....

The dampeners are lubed?

[Heli Paramedic]

Main blades are probably a little too loose. And dampers are well lubed.

[LITHIUMSTATIC]

That's a tough one..... :thinking What ESC do you run? Is it in Gov mode?

[Heli Paramedic]

ESC is the align 75Amp in Heli non-governor mode

[LITHIUMSTATIC]

It's really hard to say..... sometimes it takes a couple of people to dissect it in real life to get to the bottom of it. I'm just as lost as you now....:thinking:(

Could be a bad bearing maybe....

[Heli Paramedic]

I'm thinking perhaps it could be a gyro or tail servo problem?

I'm using the 6 arm star wheel that came with the 9254 servo. The ball is on the furthest hole out. I wonder if moving the ball in to the next hole will help. Although it does seem strange that this problem only started after a crash and rebuild.

[John Heli]

I am flying the same arm on the same setup (GY401 + S9254) with no problems. I only had this kind of wobble when the tail root was too stiff caused by a slightly oversized tail shaft so the tail pitch slider did not move easy. A change of the (new) tail shaft eliminated this problem.

[Heli Paramedic]

Thanks John heli,

I was thinking that also, but my tail pitch slider is silky smooth. The wobble was also there when I had the CNC SE version tail and continued when I changed to the plastic SA tail with a new shaft.

[John Heli]

Try moving the ball link in the middle hole. I just checked and I fly the middle hole. I can go up to 95% sensivity with 0% delay and I have no wobble / wag.

[Heli Paramedic]

I'll give that a try. I'm currently in the process of converting from an SE V1 to the V2 frames so it will be about a week before I'm ready to fly.