Okay I have issues, this is like going to psychology, I feel like I should know this, but I just can't find the solution, and I NEED HELP

My problem:
I can't get my gyro to hold my tail, if I turn gyro sense up the tail is oscillating, I can't find the sweet-spot between oscillating vs. holding tail in hard wind and fast backwards flight !!!!!

Here is my setup:
Freya 90, with 105mm SAB extreme tail blades, Futaba 401 Gyro and a Hitech HS-6965HB tail servo

Gyro setup DS=On, Dir=Off, Delay=90 and Limit=110

Gyro sense on transmitter Normal= norm=60%, idl1=AVC55 and idl2=AVC50%

Please help what is your setup like !?!?!?

http://rcheli.dk
http://birdeye.dk

First off it may not be the gyro

things to check

1.are linkages moving freely
2.is the belt slipping?
3.are the blades sliping ont he tail spindle? (hold tail and try to turn head with a little force)
4. is the headspeed too low?
5. is the engine too rich?
6. is the gyro mounted right?

as for gyro abotu 60 gain is what i have on my 50 nitro and turn down the delay a bit

Velocity 50 "99.9999999999999% of an atom is empty space." also 01001000 01001001

Why is your delay at 90? have you turned this up to try stop the wag? Have you got full travel at left and right rudder? How is your 401 mounted? 2 mounting pads?

Sorry about all the questions!

60% of the time, it works every time!

How far out is your connector out from the the center of your rudder servo on your tail push rod. I had problems with mine sometimes and found moving it toware the center one hole helped.

it should be 3rd hole out we defiantly need more info answer all the questions asked so far

Velocity 50 "99.9999999999999% of an atom is empty space." also 01001000 01001001

I can't get my gyro to hold my tail

Just wag it!

Now seriously... how are the end points for rudder on the radio? Should be close to 120%...

It's hard to see the light when the fridge door is closed

Pics of the tail, linkages and gyro mount please....

Logo 600 VBAR, and Mikado XXtreme!!!!

Answers
VooDooX
1. Yes
2. No
3. No
4. No
5. Maybe
6. Yes, the gyro mount tape from Futaba

Richardmid1
Okay I can try to set the delay up to prevent the gyro in over adjusting, that’s a good point. Full travel, yes. Only on gyro pad, do I need two ?

The rest I will check when I get home after work today in about 8 hours

Thanks for the answers this far

As you can see i did have some slop in the tail link, but that is removed now. http://rcheli.dk/2009/06/06/slop-in-the-tail/

http://rcheli.dk
http://birdeye.dk

You only need any delay if the servo is fairly slow like 0.10+. Is your tail servo getting warm/hot? if it is its a pretty good sign that vibration is affecting the gyro. On nitros I like to use 2 pads and also strap the gyro down with a velcro strap but not too tight.

60% of the time, it works every time!

Delay??????????????

Hey Buddy,you are running a digital servo get rid of the delay, then move the ball on servo arm to max 13mm from center, check your head speed my be to high or too low,also try swapping the tail blades for shorter ones maybe 10 to 15mm less than what you are running now.also make sure you tail control rod is not binding anywhere and is as straight as possible.I usually add 3 layers of double stick tape on my 401's,and one last thing you could try is move the ball on the servo arm to the first hole closest to servo screw and then max out your travel, Hope this helps good luck..BTW I would give Graig Gomez at MRC a call PH# 732-225-2100 He is Hirobo's man, knows his stuff call him first I'm sure he will have the right answer for you

Eric G

Assuming that the mechanical linkage is in good working order and relatively slop free I would:

Insure that that tail servo is running on 6vdc if your setup allows so the servo operates as fast as possible (6vdc: .08). This servo is not very fast and wasn't designed to be a tail servo. It has a 300MHz frame rate at 1500usec, so not nearly as precise and responsive as a dedicated tail servo like the Futaba s9256, BLS251, JR 8900 or MKS equivalents. While the 401 will not work with narrow band servos there are faster servos out there that will work with it you just have to look around.

However, the HS6965HB should work pretty well when run on higher voltage.

Remove the Delay, set it to 0.

Make sure the gyro is mounted with Futaba gyro tape or two layers of 3M red double-sided tape (available at Lowes and Home Depot).

Make sure the wires going to the gyro have sufficient slack and aren't putting tension on the gyro case.

Make sure your engine is properly tuned and the model is running smoothly.

Make sure your belt tension is set correctly, not too tight and not too loose. Depending on how often the temperature fluctuates where you live you make have to adjust it more regularly.

Make sure your tail rotor blades are in good shape and not nicked, chipped or otherwise damaged.

As per the 401 manual:

Set up the gyro in Rate mode FIRST so you can set the mechanical linkage/pushrod to eliminate any drift. Do this on as calm a day as possible and set the gyro gain in the radio to around 40-50% (non-AVCS mode, when the 401 is in Rate mode the LED will flash slowly, then it is in AVCS it will be on solid).

After you're done setting the pushrod to the needed length, reset the LIMIT since you've changed the length of the pushrod and the mechanical limits have now changed.

Once you have set for no drift in rate mode, switch back to AVCS model and start around 50% and start dialing up the gail until the tail begins to wag. Check for tail wag in all flight modes and if needed, set individual gains for each flight mode if the wag occurs at different gains for each mode.

If you can't get it to wag you may need to either overdrive the gyro's gain by disabling the Gyro Mix (INH) and setting gain using the GYRO channel 5 ATV.... or you may have to go in on the servo arm.

The 401 is a pretty easy gyro to setup and is pretty reliable. It is probably still one of the best gyros Futaba ever made for entry-level to intermediate use on all classes of helicopter.

- Dan Goldstein - Team HobbyHut -

Running any servo on the tail on 6v will over heat it and its performance will actually drop off if not stop working all together!

60% of the time, it works every time!

Richard,

The Hitec HS-6975HB is designed to work at 6vdc. Not all tail servos are limited to 4.8vdc. In fact, the majority of servos rated for 4.8vdc can be safely run at 6.0vdc as long as it is regulated.

See the OPERATING VOLTAGE RANGE for the HS-6965HB here:

http://www.hitecrcd.com/product_fil...4/HS-6965HB.pdf

Other tail servos that will work on 6.0vdc:

the Align DS620 (actually has been successfully run directly off a 2s lipo with no problems)...

the ACE DS0606: http://www.tiger.com.tw/product/8130.html

also see: http://www.spartan-rc.com/resources/servodb/servo.php

- Dan Goldstein - Team HobbyHut -

I am not home from work yet, but my servo is running close to 6 volt and it is not getting hot at all.

I have had one Futaba servo die on me, that is why i am using the Hitech as an alternative.

I will still get back with some more answers.

http://rcheli.dk
http://birdeye.dk

Okay back from work.

My link is 12mm out from the center of the servo horn. Endpoint settings is 110% 110%. I Think that was the answer of all the questions.

But i think that i can already conclude that i have to set my delay to 0 on the gyro. and try to setup the gyro sense level again to make sure it is working okay with the new delay.

Any comment on the 12mm from center of servo horn ?

http://rcheli.dk
http://birdeye.dk

Yes most servos rated at 6v will work fine on 6v regulated and I am running the Align DS 610's direct off a 2s li-po but when coupled with a gyro on the tail the servo is working so much harder so they work best at 5v on the tail. For the very little performance increase from 5v to 6v if any it is not worth reducing the life of a tail servo being as expensive as they are plus you will reck your model when it fails in the air!

60% of the time, it works every time!

Richard,

to each their own...

an increase in voltage will cause a decrease in current draw, and that means less heat. if a servo was designed to accept 6.0vdc or a 5-cell NiCD pack, then it will work more efficiently at 6vdc than at a lower voltage.

what really "over works" a tail servo is a higher gyro gain than actually needed, mechanical binding and flying style.

- Dan Goldstein - Team HobbyHut -