Gyro setup in a Blade 400

[Maxime30]

Hello,


I tried the 400 yesterday, and altough the helicopter itself seems to be fine, the tail didn't seem to hold well. Is there any magic settings to make the tail more flyable?? ( without spending for a 401/3400g!).


Thank you!

[carlo_the_wonder_frog]

What happened to the tail when you got into a hover? did it constantly turn, spin uncontrollably or what?

[sokal]

this is what i have done and tail holds well

go to this forum its a trex one some one recommended it to me. they apply vey well just have to translate what he say to the dx6i and b400 just diff wording but the same.


http://www.helifreak.com/showthread....11373&page=129

ccpm vids help with head setup. use the gyro for the tail, but just use the part about the tail centering. havent yet figured out what hes talking about with the gyro.i've used the tail set up and put gyro to 64 and moved up to 66.5 hold well trimed the taill a lil and it holds

[sokal]

oooops also found plug it in as soon as u get outside and its cold its not as strong

[Maxime30]

Sokal,


Your link doesn't work.


carlo_the_wonder_frog:


Actually the tail isn't locked in at all. Acts like if the gain wasn't high enough, but starts wagging before being locked-in when increasng the gain.


I increased the headspeed, lowered the rudder EPA to de-sensitize the tail. A bit better, but still not satisfied.


Next step I might install my 3400g in it just to see if the gyro works better with this servo.



Thank you!

[sokal]

http://www.helifreak.com/showthread.php?t=11373&page=133

the page keeps changing as of now this is it can be found under bob tech room
trex 450 general build vids last page in forum
sorry

its seemed to work for me but this is my first heli of this type
my other was a cpp

[Maxime30]

Thank you!

[deifan]

ADJUST LISTD\R&EXPOAILE190%INHELEV190%INHTRAVEL ADJRUDD<- 90% -> 90%GYRORATESW-GYRO0:66.5%1:64.0%THRO CURSTUNTPOS LPOS 2POS 3POS 4POS H100.0%92.5%85.0%92.5%100.0%HOLDPOS H- 0.0%PITC CURNORMPOS LPOS 2POS 3POS 4POS H35.0%42.5%50.0%75.0%100.0%HOLDPOS LPOS 2POS 3POS 4POS H35.0%42.5%50.0%75.0%100.0%SWASH MIXAILE- 75%ELEV- 75%PITC+ 85%SETUP LISTMODEL NAMEMODEL 1BLADE400REVERSEAILE - RRUDD - RSWASH TYPECCPM120*TIMERDOWN TIMER - 04:30

[carlo_the_wonder_frog]

Do not adjust the Rudder EPA ( ATV , endpoints) it does nothing to the tail sensitivity. Rudder EPA will only do 1 thing, increase or decrease your Piro rate ( How fast it spins). If you want to desensitise the tail add exponential to the rudder channel. The e-flite gyros also tend to kind of suck at holding a heading as they never seem to hold without trim.

[BKF]

When changing to another tail servo that's opposite the stock servo, what else do you have to change?

In the TX, you have to change the rudder to opposite, and you have to flip the gyro switch on the G110 to opposite. But do you have to change the gyro setting in the TX to opposite? Or is that over-ridden by the switch on the gyro?

[carlo_the_wonder_frog]

You don't have to change the gyro setting. You will have to change the gain though until it holds well. It will always drift somewhat, the e-flite gyros dont hold all that well as battery voltage and HS decline it drifts.

[OliOC]

Can anyone else offer any advice on setting up the Blade 400 with the stock (piece of junk?) G110 gyro?

I'm having a number of issues with it. In a hover it wont hold and wants to creep no matter what I do with the trim. And when gradually increasing rpms on the ground it wants to piro and needs constant rubber input to help correct it while spooling up.

I'm also having some issues with mechanical setup.

I inspected the linkages out of the box and with the slightest input (about 25%) the pitch slider would move to almost full throw. Correct me if I am wrong, but shouldn't the tail be set up so that on full tx input the pitch slider 'just' reaches the blade grip holder and gearbox case without binding?

I moved the ball link on the servo arm to 2 holes out to help calm things down, and then had a play around with the end points. I've noticed that the servo only wants to move to about 40% travel each way. Adjusting the epa anywhere beyond this point doesn't make any difference to the servo's behaviour, and I can't get the pitch slider to reach the gearbox case or blade grip holder. Even with the servo not connected to the control rod (to confirm it's not binding anywhere) there's no difference between 40% travel and 100%, so I'm not able to use all of the servos resolution. Maybe this could be the problem? Perhaps I am being dumb, but I just cant figure it out?

I just long for Finless Bob to do a setup with this gyro but something tells me he wouldn't waste his time doing so!

I'm not a complete noob, but welcome all the comments and help you guys have to offer.

[Wolfpackin]

In a steady hover my tail moves slowly to the right (CCW).
The tail never wags or twitches.

Is this most likely correctable with rudder trim or should I start playing with gyro gain settings in the TX?

They are currently set as they come from the factory (something like 64%/65.5%)

[carlo_the_wonder_frog]

Can anyone else offer any advice on setting up the Blade 400 with the stock (piece of junk?) G110 gyro?

I'm having a number of issues with it. In a hover it wont hold and wants to creep no matter what I do with the trim. And when gradually increasing rpms on the ground it wants to piro and needs constant rubber input to help correct it while spooling up.

I'm also having some issues with mechanical setup.

I inspected the linkages out of the box and with the slightest input (about 25%) the pitch slider would move to almost full throw. Correct me if I am wrong, but shouldn't the tail be set up so that on full tx input the pitch slider 'just' reaches the blade grip holder and gearbox case without binding?

I moved the ball link on the servo arm to 2 holes out to help calm things down, and then had a play around with the end points. I've noticed that the servo only wants to move to about 40% travel each way. Adjusting the epa anywhere beyond this point doesn't make any difference to the servo's behaviour, and I can't get the pitch slider to reach the gearbox case or blade grip holder. Even with the servo not connected to the control rod (to confirm it's not binding anywhere) there's no difference between 40% travel and 100%, so I'm not able to use all of the servos resolution. Maybe this could be the problem? Perhaps I am being dumb, but I just cant figure it out?

I just long for Finless Bob to do a setup with this gyro but something tells me he wouldn't waste his time doing so!

I'm not a complete noob, but welcome all the comments and help you guys have to offer.

This is all completely normal, while the heli is on the bench a HH gyro when given even the slightest rudder will go all the way to max throw. Why? because when you give it rudder it expects the heli to actually turn, while its on the bench it will never turn so therefore the gyro assumes the heli isn't moving and gives even more trying to force it to move. TOTALLY NORMAL. In rate mode the tail will center itself with the rudder stick.

The reason it doesn't hold during spool up is because the tail isn't turning fast enough to create any counterforce yet, all of my helis are like that, but soft start keeps things fairly tamed.

E-Flite does not make a good gyro (they actually don't manufacture them), it will never hold all the way through a battery pack. Try a Futaba GY401 for a very good Gyro that isn't too expensive.

Number 1 reason why the blade400 tail doesn't hold? Gyro kinda sucks.

[bebopgolf]

OLiOC is your ball link on the inside or out side of your servo arm? If you are on the second hole from the center (like I am) you might want to put the ball on the out side because mine would bind on the inside. After that get rid of your of creep using subtrim ala finless vid. gain should be above 70% in the radio mine is @ 73.5 % no wag fast backwards / sweeeeet hold.

[haucke]

I am new at this. I just finished building my first t-rex 450 se v2. I learned a lot from that build and would suggest that exercise to anyone who wants to really understand how these things work. With that being said...
I have a a Blade 400 and have been messing around with it for about a month now. I had the same tail gyro issues. Based on my experience with my t-rex I adjusted the head and tail of my Blade 400 using the same methods that I learned from the Finless videos during the t-rex build. I have it flying as good as my t-rex now. (Keep in mind I am a noob at this so my comparison is not at a pro level.) The big issue I had was my linkage to the tail rotor was not adjusted right.

1. Removed all rudder trim from my radio both trim and sub-trim.
2. I set the gyro to non-heading hold mode.
3. Set the arm of the tail servo so it was set at 90 deg to the case of the servo.
4. Then adjusted the linkage to the rotor blades so that the blades were straight.
5. Powered the 400 down and set the radio back to heading hold and powered the 400 back on.
6. I then used rudder sub-trim to adjust out the rotor blade drift.
a. This adjustment is done without any throttle.
b. There is a good finless video on this but it is listed under a different gyro. Take the time to watch all these videos they are priceless.

AGAIN I am a NOOB at this, so if any of you experts out there want to elaborate on this please do, and let me know if I missed anything. I hope this helps.

[sokal]

tail blades isnt supposed to be flat pitch

they need to have some pitch to copensate for the torque of the main rotor system

just center the slider on the shaft

if you use sub trim may vreate a rebound effect whwn stop in the turn

i use 0 trim and 0 sub and is very solid

[haucke]

Compensating for the torque of the main rotor system? That is what the gyro is for as well as wind compensation isnt it? If you put any pitch in the rotor blade when the servo is centered how is the gyro suppose to know what true center is. I think that is what was causing mine to drift. Once I set everything at center to include the blade my drift went away. Dont get me wrong there is very minor drift over time compared to my T-Rex with 401 gyro, but not enough to keep me adjusting my tail all the time, just after a few manuevers.

[SeaComms]

Setting the blades with no pitch for centre servo arm might be handled by the HH mode, but if you put it into normal mode you will have constant stick input to hold steady. The gyro is not looking for a center position, it looks for no spinning and increases/decreases pitch to try and keep it there. Under a normal stationary hover you should have in the vacinity of 8 degrees pitch on the tail blades (yes - I watch the Finless videos too :)). This is what is required to hold the tail stationary against the torque from the main blades and should be about right for center of the pitch slider. What we are looking for is the servo arm to be as close to 90 degrees when the helli is in this stationary hover position.

The proper way to set it up (according to Finless) is to adjust for centre pitch slider (which gives you your 8 deg aprox pitch on the blades) as a start, then fire up in non heading hold (round 25% on the gyro gain) and then keep testing while adjusting the ball link length adjustment until it will hover with pretty much no stick input. Then it should be spot on for HH mode. (instead of actually hovering, I set up a turntable and strapped it to it - got it to hovering speed and watched the tail. That way by the time I did actually hover it was damn close and controllable).

[sokal]

TRANSLATING TENDENCY OR DRIFT
During hovering flight, a single main rotor helicopter tends
to drift in the same direction as antitorque rotor thrust. This
drifting tendency is called translating tendency.

A tail rotor is designed to produce thrust in a
direction opposite torque. The thrust produced by the tail
rotor is sufficient to move the helicopter laterally

To counteract this drift, one or more of the following
features may be used:
• The main transmission is mounted so that the rotor
mast is rigged for the tip-path plane to have a builtin
tilt opposite tail thrust, thus producing a small
sideward thrust.
• Flight control rigging is designed so that the rotor
disc is tilted slightly opposite tail rotor thrust when
the cyclic is centered.
• The cyclic pitch control system is designed so that
the rotor disc tilts slightly opposite tail rotor thrust
when in a hover.
Counteracting translating tendency, in a helicopter with a
counterclockwise main rotor system, causes the left skid
to hang lower while hovering. The opposite is true for
rotor systems turning clockwise when viewed from above.


all above taken from an FAA ROTOCRAFT text book on helicopter dynamics


to explain
if you were to remove the tail and spool up heli copter you will see that the body will spin opposit of the blades rotation with is due to torque from the main rotor.

now to stop this you have to have an out side for counter act that spin in the body ie tail rotor now if i have 0 pitch in the tail blades is it creating any force witch will counter act the main rotor torque. NO
that is why the tail blades will have some type of pitch in them to create the antitorque of the main rotor.

what the gyro does for you is
1 help keep the nose pointed in a constant direction so that you dont have to manually.
2 when applying more thrust to the main rotor you have to add more antitorque so it does that for you so you dont have to do it manually.


a gyro is not needed to fly a heli its just make things beter for you in controls. less stress for the flyer

[Montana_Reefer]

Do not adjust the Rudder EPA ( ATV , endpoints) it does nothing to the tail sensitivity. Rudder EPA will only do 1 thing, increase or decrease your Piro rate ( How fast it spins). If you want to desensitise the tail add exponential to the rudder channel. The e-flite gyros also tend to kind of suck at holding a heading as they never seem to hold without trim.

Hey Carlo
I too am a trex guy and am trying to help set up a blade for a friend. This gyro dosen't have travel limits I think they have to be set w/ the ATV's we already burned up one servo. It just crept over and sat there till it smoked! When using the old style same as the align gyro you need subtrim to stop creep.