9CHPS Gyro sensativity Adjustment Help

[EdgeCrusher]

Hey guys

Im having some trouble getting my 9CHPS to adjust my gyro gain. I went into my Gyro Sensitivity menu and went to "GY" and lowered my value from 80 to 60 in hope to cure a small wag issue after i installed the new T-600 Tail hub. All i can seem to due it make my Piro rate EXTERMLY fast. Which leaves me confused cause i thought my Turn Rate was adjusted from ATV's. Either way i would like to know what im doing wrong. I did notice that when i make any changes in my "GY or STD" menu they effect Each other, is this normal?

Sorry for the silly question im still learning my first futaba Radio.

[WayneBrown]

I absolutely hate the gyro menu, and go old school to setup the gain and piro rates.
In the event you can't get help, I'll be up in the cities the first Sunday night in March for a meeting Monday morning. I'm sure we can find a parking lot that's lit up to setup and test it.

[MarkD]

Yaw rate is usually set by the Rudder Ch ATV's (Ch4). The gain should be in Ch5. The 9C GY and STD modes are similar but use differing vaues for the same thing

GY mode is -100 to +100 where -100 to 0 is NOR rate and 0 to +100 is AVCS rate
STD runs from 0 to 100 where 0 to 50 is NOR and 50 to 100 is AVCS

So -50 (GY Mode) is NOR which is the same as 25 in STD Mode
+50 (GY Mode) is AVCS which = 75 in STD Mode

You can also use the ATV on Ch5 to achieve the same thing

[EdgeCrusher]

Ok i can pretty much understand that. So where im still left confused is why when i lower my Values in GY mode am i only adjusting my Yaw Rate, i went from 60 to 40 my first time and the turn rate was way to fast.

[DavidH]

When you lower the Values in GY mode. Your only lowering th sensitivity of the gain. Yes the tail will piro a little faster, but it will also not hold as well. 40% in AVCS or Normal mode should hold the tail well. You can probably run 90% and the tail will not wag, but all your doing is overworking the servo and it will wear out prematurely.
ATV on channel 4 ( Rudder) is how you should speed up or slow down your pirouette rate.

David

[tppjr]

OK, I have been following this and have a question. I adjust my ATV (D/R for Futaba) from 100 to 140 and assign it to a switch so I can switch between the two I get a big difference in piro rate. My question is that how can I get it to spin the same rpm in both directions. Can't it compensate for the main rotor interaction?

Thomas

[EdgeCrusher]

When you lower the Values in GY mode. Your only lowering th sensitivity of the gain. Yes the tail will piro a little faster, but it will also not hold as well. 40% in AVCS or Normal mode should hold the tail well. You can probably run 90% and the tail will not wag, but all your doing is overworking the servo and it will wear out prematurely.
ATV on channel 4 ( Rudder) is how you should speed up or slow down your pirouette rate.

David

I thought the same thing but even when i go to values as low as 10 on AVSC "GY" mode the tail HOLDS awesome but it still wags and piros around 2- 2 1/2 times per 1.5 seconds which is way beyond what i want to run.

OK, I have been following this and have a question. I adjust my ATV (D/R for Futaba) from 100 to 140 and assign it to a switch so I can switch between the two I get a big difference in piro rate. My question is that how can I get it to spin the same rpm in both directions. Can't it compensate for the main rotor interaction?

I was just reading last night that running Different ATV values left to right is OK to get your yaw rate equal, butt Ive never noticed a large difference between left and right.

[DavidH]

I thought the same thing but even when i go to values as low as 10 on AVSC "GY" mode the tail HOLDS awesome but it still wags and piros around 2- 2 1/2 times per 1.5 seconds which is way beyond what i want to run.


Sounds to me like the tail linkage is binding or the blade grips on the tail are in a bind. If your getting wag with the sensitivity low, then something is definitely wrong in the tail system.

The heli wants to piro to the left easier. It is going with the torque of the main blades when going left. Trying to pirouette right it is going against the torque of the main blades. So it takes more power to piro right.
If you have the tail control system set up correctly. The ATV's on rudder will be pretty close and the piro rate will be close to same speed.

Yes if you have the gain set at 10% the GY is virtually not doing anything. I would think it would not be holding well and would piro fairly fast.

David

[EdgeCrusher]

Ok well im left even more confused then before. I don't know what i did but it is working just fine now around 55% "GY" I don't know what was making my yaw rate so fast before cause i could swear i was adjust the same values. Now the piro rate is where i like it and the tail holds good and im not getting any wag.

Thanks for the help.

[tppjr]

I was just reading last night that running Different ATV values left to right is OK to get your yaw rate equal, butt Ive never noticed a large difference between left and right.

Anyone know where in the 9C you adjust for ATV?

[EdgeCrusher]

Yes, its under your Basic menu and its the END POINT menu you want.

EPA/ATV same deal

[tppjr]

Yes, its under your Basic menu and its the END POINT menu you want.

EPA/ATV same deal

OK, got it, I think. So I can set each side different to get it so the piro is the same speed in both directions, right. :?: :?:

Now what is the D/R for? I understand the EXP part but not sure about the D/R.

Thanks again,

Thomas

[MarkD]

Yes, its under your Basic menu and its the END POINT menu you want.

EPA/ATV same deal

OK, got it, I think. So I can set each side different to get it so the piro is the same speed in both directions, right. :?: :?:

Now what is the D/R for? I understand the EXP part but not sure about the D/R.

Thanks again,

Thomas

Dunno but your avitar is really doing my eyes/head in

[Laddy]

Mine too.

[DavidH]

D/R is Dual Rate
The Dual part comes in that you can adjust it like the ATV/Endpoint. You can put this function on switch and lets say for example you have the End point adjusted to 90%, you can adjust the Dual Rate End point to say 50%. When you flip the switch that is controlling the dual rate then the end point will change to 50% from 90% and vice versa.
Normally Dual rates are used on Rudder, Elevator and Aileron functions.

David

[BarracudaHockey]

was just reading last night that running Different ATV values left to right is OK to get your yaw rate equal, butt Ive never noticed a large difference between left and right.

You should not have unequal end points with the 401, it effects the center pulse somehow, Dr Ben can explain it because I know I'll butcher it and David will make me fell stupid :D

[DavidH]

Feel or Fell? <G>

No Andy is correct. If you have a large offset in the ATV values it does affect the center position. For example if you have 100% ATV one direction and 50% ATV the other direction. The center position is now offset some.
If you have a radio that has AFR( adjustable function rate). You can offset the AFR values and this will not affect the center position.

David

[EdgeCrusher]

First off please don't take any of this as if I'm being rude I'm just trying to understand. How about an ATV offset around 3-5%(difference) would that still have a centering problem? I just don't get how ATV's can change your center stick position cause from what i understand your only changing that servos operation in the trail end of its movement if your values are within reason. Maybe that has something to do with gyros specifically?


A little help :D

[DavidH]

3-5% don't really make a difference. It usually starts showing up when you get above 20-25% difference.
ATV's are affecting the travel range. Yes that is the end points basically, but also the whole range.
It is not just something with gyros. I have seen throttle curves that are hell to get adjusted correctly because the ATV on one end would be like 120 and on the other end like 70. Couldn't get the curve adjusted correctly till there was only 5-10 % difference at the most. Of course the mechanical setups are way off in these cases and that affects it also.

David

[Dave]

Dual Rates and Expo do somewhat the same job but they do it differently.

By using Dual Rates you can slow down response by flipping a switch and in effect make it less sensitive to stick movement.

Expo does the same thing around center but you have the full rate at the extreem of movement.

A beginner may prefer dual rates over expo. If he over reacts the heli will not. With expo and extreem stick movement you may end up with too fast response. With Dual Rates you do have one or more switchs that you would need to use which also can be a negative to a beginner.

Of course you can use both.

I am somewhat surprised that the ATV end points also affect the center. It was my understanding that changing the end points have no effect on the center. Does this vary from radio to radio or do all radios work this way?

[DavidH]

Dual Rates and Expo are not the same .

Dual Rate is just as the name says. You can have two different rates of travel.


Expo just controls the travel off center.

In my opinion Expo is more beneficial to a beginner. Most of them I have seen over control the cyclics and rudder off mid stick. So 40% of softening expo will usually cure that and they still have full travel at full stick if needed.

David

[Dave]

I agree, dual rate and expo are not the same but they do have simular end results. Both flatten the curve near center which is what is important. The biggest differences between the two is at the extreems of stick travel.

They definately are not the same and I did not mean to imply that they are the same.

Dual Rates slows everything down, expo just slows down the center. That statement may be an over simplfication but I believe it is accurate.

I had envision ATV as somewhat of a 3 point curve. The center is controlled by trim and/or offset and the ATV controls the two end points. Is this inaccurate?

[DavidH]

On Futaba radios
Negative precentage- softens the input off center stick
Positive precentage - increases the input off center stick

JR radios are opposite from Futaba

ATV is adjustable travel volume- This controls the total range that the servo travels. It is controlled one side by one precentage. The other side is controlled by the opposite side. The center pulse is really not controlled by ATV. Thou it can be affected if the differential is large between the ATV precentages.

Dual Rate is a linear adjustment that controls ATV's
Expo is a non linear adjustment that only controls sensitivity from center stick.

David

[EdgeCrusher]

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