FBL Gyro Hk401b tail wag issues........can anyone help?

[cantyman]

HELLO GUY'S.....HAPPY NEW YEAR!!!! Im here to get help with a HK401B gyro....whats happening is a pretty serious tail wag. Im working on a few projests and I wave switched to a different 401B because I thought the other was faulty. I have agjusted the gain to almost off ...then off .....still getting the wag....Then i turned it all the way down.,,,,, so you can imagine that there is a high level of frustration here....Am I missing something....here is the set up:

450 clone
HK 30A UBEC
Turnigy H2218 3200KV brushless
HXT900 SERVOS (4)
HK401B GYRO
3s 1800mah li po

Any help will be appreciated. What am I missing here.....could it be head speed....so maybe throttle curve???.....My head is just spinning here.....I know its something simple....I hope someone can point me in the right direction.....

Thanks in advance guy's

 

[coolgabsi]

HK 401 is a Futaba 401 clone.. working is similar..

ok.. so when you say you have turned the gain off.. is that on the gyro or in your transmitter?

using a slow servo also can cause a tail wag.. HXT 900 is analog or digital ? whatever it is.. does it match the dip switch settings on the gyro.. ? then.. if you are getting tail wag in rate mode, then you might be looking at the tail gyro too slow.
have you ruled out any .. ANY.. mechanical bind.. is everythin smooth as silk?

 

[Westy]

HXT 900 is too slow I think.... I biffed mine off the tail when I had a 450 and put on a DS520 Align one.

Have you read the Gyro setup guide in the Beginners Help on the 450 Section.

how have you set your mechanical setup with the radio Limits at 100 and your limit on your Gyro dial to between 80 -105?

Also the distance from the centre point on your servo shoudl be no more than 8.5mm (radius) the ball joint.

 

[cantyman]

Hey Coolgabsi......thanks for your reply.....

Yeah...so when im saying i turned the gyro of ...I mean down to zero....and then all the way up......it didnt seem to help....as fot the transmitter...Im using the fly sky CT6B....and im using the digital radio software down load to program the radio....it seems pretty straight forwar and easy...but I will re check the setting to be sure.as foar as a slow servo....i think HXT900 are .12 sec so???? They are all analog and the gyro is set up for them....meaning the dip isnt flipped up do the DS or digital servo mode....it wags in rate and in HH mode...so this really has me stumped!!!!....As far as the mechanical....it seems to be very smooth no bind whatso ever....Hmmm.....I gues i will just have to keep looking at this point.....maybe there is something Im missing......hey ...but you help is appreciated thats for your reply

 

[Westy]

....it wags in rate and in HH mode...so this really has me stumped!!!!...

That means the servo is Too Slow. U need a 0.08/sec or faster.

that will solve your issue.

SInce it wags in Rate mode.... the gyro is not influencing at all in this mode and since it is still wagging this indicates lack if speed on the servos behalf.

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Also .. .are you getting full mechanical travel from left to right. If not you may not be getting enough tail rotor influence to compensate.

 

[cantyman]

oK WESTY......I WILL GIVE IT A TRY........ANYTHING TO GET RID OF THIS HEADACHE......LET ME ASK......CAN I MIX SERVOS.....MEANING ANALOG ON THE CYCLIC AND DIGITAL FOR THE TAIL???? HEY THANKS FOR YOUR FAST REPLYS.......ITS APRECIATED

THANKS TO ALL AGAIN

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THE ANSWER IS YES.....FULL TRAVEL

 

[Westy]

hey CAntyMan...

Yes you can and no you cant.

you can use a Digital on the tail and Analogs on the Cyclics.... If using a digital ... make sure you use the correct Dig or Analoc dip switch setting ... also the HK401's are proned to the main board coming loose ... so you can you tube it and there is a hot glue fix that works .... come to think of it ... try that first before you do anything... you may be surprised as to the result.

But Do not mix digital and analog on the cyclic. Always use the same servo and model. If you are changing brand or type on the cyclic ... you need to get all 3 not just one unless you are swapping out same for same.

Hope that confusing dribble made sense.... ha ha .....

If you change to Digital on the Tail (highly recommened) get one that is 0.08/sec or faster.

you can get them pretty cheap second hand with low milage if you can wait for the right deal to come along.
you can use a mini or a standard on the tail with the right bracket.

Let me know if you want a hand to find a good one! cheers

here is the You Tube Mod/Fix - hope it fixes your issue

Watch this one through first then the second one....

 

[Westy]

Here is a nice servo for a good price (Second hand)

1 Align 650 tail servo - $45.00 Shipped


Here is a smoking hot deal on a complete set of Align 450 Cyclics and a Tail servo .... better jump!

 

[coolgabsi]

That's too big for this size... If its 450 you need ds520 for a pro design

And from what I see he is using a 9h servo he needs ds420 or Ds425 whatever is the latest 9g

And this gyro setting you said you are changing is on the transmitter right? Through the pc software .. There is no gain pot on the gyro

Just making sure we are on the same page

Ok.. How about mechanical .. May be I missed it.. But is that smooth?

Fly safe!! have fun!

 

[Tony]

It would be the DS415 for the cyclic and 425 for the tail. I can say this, that blue plastic gear servo will not hold that tail very well. If you spend a LOT of money for anything on a heli, you need to do it with the gyro and tail servo. If you can put a 26g servo on the tail, get the DS525 and the GP790 gyro. your tail will be locked in solid after that. If you can't put a 26g servo on the heli and need to stick with the 9g, then get the DS425. Either way, I would HIGHLY suggest you get rid of that 401 gyro. I had two of them and they were pure CRAP. I did all of the mods and they were still crap. Now, I'm all align and everything is ROCK SOLID!

 

[Westy]

I like My Curtis Young Blood Mini-G .... solid as a rock .... picked one up for $30USD landed in NZ .... what a steel! works like a charm