New Tail Servo Hele Now has the wobbles

[infacto]

Hi guys

Got the new servo you guy suggested (HDS-577 18g Micro Digital Servo)

Fitted it so it was centered and has plenty of movement in both directions.

All was looking fine on spin up hele stayed tail in with no drift. Took off and the tail began to wobble left and right. Well what did I do wrong do you think.

Any tips would be much appreciated.

Infacto

[marktigere1]

How high is the gain on the gyro?

Too high a gain and you get tail wag.

Try reducing the gain a touch.

Cheers

Mark

[infacto]

Ah
Maybe the old servo was much slower to react and the new one is much quicker and hence doesnt need so much gain on it.Sounds like a plan .

I'm poping home lunchtime to let the dog out and will try it out.

Thanks

infacto

[Ade_Law]

same servo horn length? The 577 is much more accurate meaning the mechanical gain is higher.

you could drop the gyro gain. but what is it set to at the moment?

Ade

[infacto]

Its set to just under 100

I moved it lunchtime to about 85/90 Its a bit better but not as good as it was.

Infacto

[Ade_Law]

what gyro is it? if its a 401 it should never be set that high, who set it up there.

Ade

[infacto]

I will check tonight what type.


The guy I bought it off set it up and to be fare it flew lovely until I crashed it.

[Smoothound]

What heli is his on?

I have 577's/401's on both my T-Rex and there is no way I could set the gain that high

[Fixxxer]

For what it's worth I run my polo digi 4 & 401 at 70% in HH, 78% @ rate mode with the servo horn link at 5mm from centre, that is on a x400 but pretty similar I would suspect.

[Ade_Law]

do you have any issues with wag in forward flight? 70% is going to be working that servo pretty hard might be worth dropping it down until you see a degredation in the performance high gain doesnt always give you a wag in the hover. You want to be under 60.

Infacto if your using a 401 did you run through the setup again when you changed the servo? Gyro setup isnt perticulary self explanitary and the little stuff can be very finicky.

Ade

[Smoothound]

For what it's worth I run my polo digi 4 & 401 at 70% in HH, 78% @ rate mode with the servo horn link at 5mm from centre, that is on a x400 but pretty similar I would suspect.

I use 5mm on the servo arm so at least we agree there Thats an odd one Fixer as on mine I have to have the gain lower in Rate than HH

[Fixxxer]

Mine was originally lower in rate but I changed something a while back & now it's arse about face but still seems to fly fine......did fly fine !

Will have another mess with it and see if I can reduce it to around 60 as suggested. No forward flight probs that I am aware of tho.

[Ade_Law]

rate mode whats rate mode? isnt it used to check the setup occasionally?

:-)

Ade

[Fixxxer]

now now

[infacto]

There is a setup for it ! Then the answer it no. Would not have a clue.

I did center it the same as the one I took off.Horn length is 5mm but the servo hangs down lower than the little one I took off.

Didnt have chance to fly last night as I was under orders to decorate the lounge from she who must be obayed!!

I'm Flying(or being flown by) a T-rex 450.

The gyro is Futaba GY240 gyro.

OK

Thanks for your help on this guys.