Problem when turning/piro the Extreme/Gy601

[Knud Pedersen DENMARK]

I have a problem with the tail on my Fury Extreme.
- When hovering in Idlup2 (Only tested it in idleup2)
- Then turn the nose fast to the left, approximately 45° - after stopping the turn, the nose turns 3-5° the other way (Without touching the transmitter sticks) .

I do not see this problem when turning the nose to the right…..

I use:
GY601/S9251
SAB J.Krause 105 mm tailblade
In the Gy601, I have only change the Limit to 140. the rest is default values (flying in F3C mode)


1.
Can the problem be that I have setup the tail linkage, by hovering in Norm-mode, with the Gyro in NON.Headinglock, and then adjust the linkage so that the heli kept heading (Not turning)?
Should this be done in Idleup2 ????

2.
I have today read in the manual for the GY601, and maybe the “Gain Tracking” function will help me?
Anybody using this features ???
:?:
ChopperKnud

[ChrisLaFollette]

I adjust the tail rod so it has equal travel both ways and let the HH take care of where the servo needs to be. It wont ever be perfectly centered while flying unless your hovering on a calm day. I run a gain amount of 38% in heading hold. I would suggest flying in 3D mode. It has better control over the piro rate during piro-loops, etc.

[DavidH]

Knud,
The gain tracking does help problems like your experiencing. But if you adjust the tracking, it is going to affect all the flight conditions also.

Put the rudder trim in the neutral ( center postion). Make sure all mixing for the rudder is disabled.

Hover the helicopter with the gyro in Normal mode. Mechanically trim the tail rotor linkage till the helicopter will hover straight without any rudder input. Once your satisfied with the heli hovering the helicopter the tail will stay put without any rudder input.
Now land the helicopter and let it idle. Flip the switch that controls AVCS and Normal mode back and forth three times real fast. Now put the gyro in AVCS mode, the heli should hover straight without any rudder input.

What type of transmitter do you have?
If you have a 9Z, I use the delay function on the rudder channel. The delay menu is behind the ATV menu.
You also say you have the limit set to 140. At 140 is the pitch slider traveling as far as it can in each direction? How far out is the ball on the tail servo wheel?

Also check the foam tape holding the sensor. Since this is only happening to the left. It could be the tape is giving up and allowing the sensor to twist when the stop command is given. It would show up when left is given because the heli is moving with the torque and it is harder to stop rotation .
David

[Knud Pedersen DENMARK]

Hi

Sceadu50dude:
Maybe I should try the ”3D”mode……just wondering if it is better, because J.Krause, on his homepage, write that he flies in “F3C”-mode……

--------------------------------------------------
DavidH:
I actually switch off the Rudder trim on my 9Z WCII, and then did the Mechanically Setup – I don´t think i did that with “toggle switch for the AVCS/Norm control” - i think i just switch of the heli, and restarted the heli/gyro in AVCS...... - is that bad :?: :oops: :oops:

- Must I do the Mechanically setup I Flight mode NORM or IDLEUP?

LIMIT:
The pitch slider almost hit the gearhouse/tailrotorhub……
I use the Big Futaba servo wheel, and use the hole at the largest diameter….

I will check the Gyro tape…
OBS: I use Velcro around the gyro sensor…..

ChopperKnud

[DebianDog]

Velco?

[Knud Pedersen DENMARK]

yes - I use the Original GY601 Tape+ plate, and then I have Velcro around the sensor - because I have seen that the tape (On my Gy401) did wear out – properly due to the fuel/Smoke….

ChopperKnud

[DavidH]

Knud,
I don't use the metal plate that comes with the GY 601. If your mounting the sensor on a metal surface it is not needed. Only time I have used the metal plate is when I was mounting the sensor on a carbon fiber surface. That is the reason the metal plate is included with the GY 502, 601, 611.When the 601 was first released the metal plate did not come with them. It was about 4 months after release when the plate was included.
I have not used the Futaba foam squares since the G501 came out in 94. After I had them separate one time that was enough for me. I use 3M Products 4408 double sided vinyl foam tape.

David

[Knud Pedersen DENMARK]

DavidH:How far out is the ball on the tail servo wheel?


I use the hole in the middle - what are you, and other using ????

I also noticed when the servo/Gyro is at "center postion", the servowheel is standing 90°, but the ballcrank after the servo, is not standing straight up/down - thst is not good, or?????

Is limit 140/140 to much (maybe not if using middle hole...)????




ChopperKnud

[DavidH]

but the ballcrank after the servo, is not standing straight up/down - thst is not good, or?????


The way the bellcranked is shaped. It may appear that it is not 90 degs to the rest of the setup. What your looking for on that bellcrank. Is both balls on the bellcrank should be lined up so they form a 90 deg angle to both pushrods. The one from the servo and the one going to the tail rotor.

I am about 16-18 mm I believe out on the servo arm. I would have to look, but I think my limits are in the 120 range.

David

[Knud Pedersen DENMARK]

DavidH: I am about 16-18 mm I believe out on the servo arm.

Is that the "arm" at the tailrotor gearbox?

[DavidH]

No that is the distance the ball is out from center on the tail servo wheel. I am using the Tempest FAI pitch slider on the tail. I am on the outer hole on the arm of the pitch slider. When I used the plastic pitch slider on the tail, I still used the outer hole on that arm also.

David

[Knud Pedersen DENMARK]

did some search (also on RR) and it looks like I maybe should use the inner hole on the ballcrank at the tailbox.....

[DavidH]

You can use the inner hole on the bellcrank at the tailbox. But be aware when you move into the inner hole on that bellcrank. Your going to have to redo your mechanical and electronic setup completely. Moving to the inner hole allows the tail pitch slider to have more travel with less travel provided from the servo.
I personally don't see any reason to use the inner hole on the tail rotor bellcrank.
There is more than enough travel if everything else is setup correctly.

Could you direct me to where you saw on RR to use the inner hole?

I have not used the inner hole of the bellcrank on the tail since the days of the spinning wheel gyros.

David

[Knud Pedersen DENMARK]

sure DavidH
Here they is:
http://www.runryder.com/helicopter/t224713p1/
http://www.runryder.com/helicopter/t15012p1/
http://www.runryder.com/helicopter/t199228p1/


ChopperKnud

[DavidH]

Then turn the nose fast to the left, approximately 45° - after stopping the turn, the nose turns 3-5° the other way (Without touching the transmitter sticks)

Well you can move to the inner hole if that is what you want to do. I don't think it will cure the problem you posted about above. That first thread was referring to a GY 401 also, I remember some pilots trying to increase the mechanical gain, so they could decrease the electronic gain. That first thread you posted you had to dig to get that one out of the archives. That one is over 3 years old.

David

[Knud Pedersen DENMARK]

Hi David

I will try this tommorw:
Shorten the linkage from the servo, so that the bellcrank is straight up/dowm, when the servo is at 90°, and gyro in "neutral"

Then adjust the linkage to the tail, so that the bellcrank at the tail is 90°.

Then I wil:
DavidH: Hover the helicopter with the gyro in Normal mode. Mechanically trim the tail rotor linkage till the helicopter will hover straight without any rudder input. Once your satisfied with the heli hovering the helicopter the tail will stay put without any rudder input.
Now land the helicopter and let it idle. Flip the switch that controls AVCS and Normal mode back and forth three times real fast. Now put the gyro in AVCS mode, the heli should hover straight without any rudder input.


BUT: should that Hovering in Non HH - be in flightmode NORM or IDLUP????

And can is just stop the heli, switch it off (electrik Power off), and resetstart it in HH (I mean skip the "Flip switch")????????
ChopperKnud

[DavidH]

Knud,
The gyro has no idea what flight mode the helicopter is being flown in. All the gyro knows to do is what the transmitter tells it to do.

Page 31 of GY 601 instructions
[During use]
When the rudder was re-trimmed in the Normal mode and the new
trim position also affects the AVCS mode, the rudder trim neutral
position must be memorized in the GY601.
Re-reading method
In this case, quickly switch (interval of within 1
second) the transmitter remote gain switch between the
Normal and AVCS sides at least three times and
switch the AVCS side at the neutral trim position set in
the Normal mode. This memorizes the new rudder
neutral position in the GY601.
When the transmitter has a function that allows trim
setting for each flight condition, such as the T9Z, the
AVCS mode trim position is fixed and this operation is
unnecessary.
Never use the transmitter rudder trim in the AVCS mode.
When the rudder is trimmed during flight, the neutral position will
change.
When using the GY601 in the AVCS mode, set revolution mixing
to OFF.
When the rudder neutral position was changed by the linkage,
the rudder neutral position in the AVCS mode must always be
re-read before use.

David

[tnreefguy]

Also check your endpoint adjustment in you radio for the gyro. It will affect the piro rate one way or the other.

[Knud Pedersen DENMARK]

Hi

The reason for asking if the tail should be mechanical trimmed in flight mode norm or idlup, is that because of the different head/tailspeed - or does the more torque follow the more tailrotor speed ???
mmmhhhh

Or am i wrong:
Will the more torque and more rotorspeed, "follow each other" - and therefor it does not matter if I mech.adjust the tail linkage, in flight mode norm or idleup????

[3DME]

I would do the mech adjustment at what ever head speed you normaly fly at, but it will not make much difference, either way you want the heli to stay still in rate mode.
Mike

[DavidH]

It does not make any difference if you do the mechanical adjustment at 1200 rpm or 1900 rpm. Again the gyro does not know what the rotor head or tail rotor rpm that is being used. The gyro just makes corrections when it needs to make them.

David

[Knud Pedersen DENMARK]

I have now tried to RE SETUP my tail/gyro. I did:

- Switch the heli on with Gyro in HH, then switch to Non HH, controlled that the servoarm was 90° (It was)

- Then shorted the linkage to the bellcrank, about 3 mm, so that the bellcrank was straight up/down.

- Then adjusted the linkage to the tail so that the arm was 90° to the tailrotor axle.

Did go to the flyingfield (<0° gray weather – in Denmark L )

- Started the heli in HH, switch to NON HH, did hover in Norm + idlup 1+2, adjust the linkage.

But either the nose did turn a little to the left, then when adjust the linkage (1/2 turn) it goes to the right…..

- Toggled the gain switch HH/ non HH

I tried flying in HH (with both type of drifting side), and it still kept drifting a little back, when turn fast 45° nose to the right.
BUT the 45° to the left was better, more accurate!!!

When I came home, I dod look at the GY601, and when I did my Non HH hover, it was with 35° NON HH gain,,,,,,maybe that was to little?

Or should I have trimmed the “linkage” with the
transmitter trim (with I normmaly have switch off / inactive)?
Or used some Subtrim?

:arggg:
ChopperKnud

[TerryBelanger]

Don't use subtrim or trim on the rudder channel. Make sure that you toggle between no HH and HH a few times after you adjust that tail linkage when flying. This resets the center point. Otherwise the nose will drift.

[Knud Pedersen DENMARK]

Hi BDIS

I think you misunderstood me:
Using the Transmitter trim or Sub trim, is when setting up the mechanical heading of the nose, when flying in Non HH (I know that I can´t/must NOT touch the transmitter trim, when the gyro is in HH)

And by:
I tried flying in HH (with both type of drifting side), and it still kept drifting a little back, when turn fast 45° nose to the right.
BUT the 45° to the left was better, more accurate!!!

i mean, when hovering and the add fast leftnose stick, so that the nose turns 45°, and then stop fast, the tail swing back (nose swing to right) about 5°.
When doing fast turn nose left for about 45°, it stops sudden and fast without svingen back the other way, and without hunting.


Maybe I should try to use the “Gain Tracking” feature in the GY601.????
Or try moving the ball to the inner hole I the arm at the tail???

[kthane]

Change the gain tracking to +10. See if it gets worse or better :smokin: