Post Your Tarot ZYX Heli Setup Here

[NexxuSix]

Hi all,
I've got my first Trex built... It's a 500e with the DFC flybarless head and torque tube upgrade. I am also using a Tarot ZYX gyro. I should mention I had this gyro mounted on my Blade 400 and highly impressed with how stable the 400 became after a little dialing in.

Not so with the Trex 500e. I am using BeenFlying's setup, and dialed down the Agility a little. The gyro is mounted on the side of the heli, just about even with the TT.

I can spool smoothly, and take off, but the minute I get airborne, I get a bad case of TBE with the heli. I have moved the battery forward to adjust the CG, and I'm using the stock hard plastic dampers that come with the DFC head. The servo links are in the last outermost holes.

I have dialed down the PID to 20-20-5, and while this greatly,reduces the wobbles, the Heli doesn't seem as stable, and still has a slight case of TBE.

I've read through this entire forum, looking a different settings and notes... All good stuff, but can't seem to get my 500e dialed in no matter what try. By comparison, my Blade 400 was very stable. The only real difference is how the gyro was mounted... Level on the gyro deck for the Blade 400, on the side for the Trex 500e. I mounted it on the side to facilitate programming and dialing in of the gyro...

I'm really stumped with this... And have tried a number of things to eliminate the wobbles, but cannot eliminate them entirely. Any help or,suggestions appreciated...

Thanks in advance!

[Mikej]

By dropping the PID values that low you have pretty much turned the ZYX off. If the problem is a wobble / oscilation then you need to drop the Roll Total Gain and the Pitch Total Gain on the Gyro Total Gain menu, not drop the PID settings.

[NexxuSix]

@MikeJ: Thank you! That seems to help significantly! I put all of BeenFlying's parameters back into the gyro, and dialed down the gain for Pitch and Roll to 20. The heli seems a lot smother, but a little touchy, so I dialed down the Agility to 25. I no longer get the TBE effect, but I do get a slight head / tail bob while hovering. I wonder if that has to do with the stock dampers, or is there another parameter I can dial in a bit to smooth out the heli the rest of the way?

Thank you again for your help... I was about to give up here... Now I can see the light at the end of the PID tunnel

[Lighty]

I don't have this unit but a head wobble on hover can be the cyclic gain being too high.

[Dr. M]

Originally Posted by Lighty

I don't have this unit but a head wobble on hover can be the cyclic gain being too high.

or it could be low HS.

Nexx, can you tell us what servos you have and how long your servo arms are. Also BEC voltage and throttle settings. What FBL head are you using?

[NexxuSix]

Originally Posted by Dr. M

or it could be low HS.

Nexx, can you tell us what servos you have and how long your servo arms are. Also BEC voltage and throttle settings. What FBL head are you using?

I'm using Align DS510's for cyclic, DS520 for the tail. Not for sure what the BEC voltage is, but the ESC is the preprogrammed stock that comes with the 550e. I'm using then Align 500 DFC head with the hard stock dampers. Servo arms are stock as well, with links set at the last hole out (10mm from servo center to link ball). The throttle curve is linear with 0-25-50-75-100, with pitch at -4, 0, +10.

Hope this helps. I also moved the battery forward about 1.25 inches to balance the CG of the heli...

[NexxuSix]

Originally Posted by Dr. M

or it could be low HS.

Nexx, can you tell us what servos you have and how long your servo arms are. Also BEC voltage and throttle settings. What FBL head are you using?

I need to correct something: The servo center to ball link is 20mm, not 10mm as previously stated...

The Tarot manual specifies 14-14.5mm for cyclics, and 7.5-10mm for the tail. I don't seem to have any tail issues. I set up the servos to Align specs at 20mm (outmost hole, according to build instructions).

[Dr. M]

Yeah that makes more sense. 10mm was looking kinda odd...

I think it's worth trying to take the balls one hole closer to center on the cyclic servo arms. It definitely sounds like you have too much gain in the system and it could be mechanical in nature. As long as the geometry still works, try the shorter position...

[NexxuSix]

Originally Posted by Dr. M

Yeah that makes more sense. 10mm was looking kinda odd...

I think it's worth trying to take the balls one hole closer to center on the cyclic servo arms. It definitely sounds like you have too much gain in the system and it could be mechanical in nature. As long as the geometry still works, try the shorter position...

That makes a lot of sense. I moved the ball link back one set of holes tonight, which is a little more than 3mm closer to center, and a lot closer to Tarot's spec for the 500 size helis. I also re-leveled the swashplate. I will squeeze in a test flight hopefully tomorrow, and update my progress... Hopefully, I will have some good numbers to post to this thread before long.

From what I've read some people are dialing down their I gain a bit also to cancel out oscillations. That might be something to consider to fine tune the system...

[NexxuSix]

Successful maiden flight!

Thanks for the help guys!

Here's my setup:
Trex 500e
DFC head upgrade
Torque Tube upgrade

BeenFlying's parameters for Tarot, and DX6i

*IMPORTANT* Ball link for cyclics is third hole from center or second from the end.


Video:
[ame]http://www.youtube.com/watch?v=_XHE9VfigW4[/ame]

[Dr. M]

Well done!

It looked like your HS was just shy of 1800rpm, which is really low for a 500. I don't think you can do much more than hovering and FF with HS that low. Caution! ZYX gains are dependant on HS, in that the higher the hs, the lower the gains need to be to prevent oscillations.

[NexxuSix]

Originally Posted by Dr. M

Well done!

It looked like your HS was just shy of 1800rpm, which is really low for a 500. I don't think you can do much more than hovering and FF with HS that low. Caution! ZYX gains are dependant on HS, in that the higher the hs, the lower the gains need to be to prevent oscillations.

Thank you, and good advice!

That would make sense: Higher HS = Lower gyro gain..

Most of the time I will be doing AP, and therefore hovering alot. But, on occasion, I will be brushing up on my circuits, so I could see where I could get into potential trouble with lower HS. Is there a work around for automating the gyro gain? I have a DX6i, but very soon will be getting a DX8

[Dr. M]

Yes, you can use the two different banks of settings on the gyro, called "conditions". Set up one for low HS, and the other for high HS. Assign your gear channel to switch conditions rather than tail gain and set up your radio to use the FM switch to also operate the gear/gain channel. This can be done on the DX6i as well as many other radios.

[NexxuSix]

Originally Posted by Dr. M

Yes, you can use the two different banks of settings on the gyro, called "conditions". Set up one for low HS, and the other for high HS. Assign your gear channel to switch conditions rather than tail gain and set up your radio to use the FM switch to also operate the gear/gain channel. This can be done on the DX6i as well as many other radios.

Ah... I just discovered something. There are two versions of the programmer software available on the web:

http://fbl.net.nz/ <--- 3rd Party Software
http://www.0577mx.com/ <--- Chinese Manufacturer (Official software)

If you can deal with a little Chinese from the manufactures programming software, you will benefit from having the ability to program the "Conditions" you mentioned above, which are found in the advanced menu. It seems the 3rd party software doesn't support this feature (yet?)

You had mentioned HS also. At the time of my maiden flight, I was flying in NORM settings. I have switched over to FMode to test the setup, but that seems nearly double the HS. Is there a recommended HS for use with the Tarot ZYX? Which parameters on the advanced menu would you adjust for higher HS's for the second Condition?

[Dr. M]

In my experience, a 500 starts to feel sporty around 2400 RPM, it gets pretty fast at 2600, and balls-to-the-wall fast, smack 3D at 3000. I wouldn't go any higher... It's really a matter of preference, flying ability and style. If you wanna do AP, by all means, keep the HS low - this will give you a mellow bird, low vibes and long flight time.

If you do want to run higher HS, though, you might need to drop the cyclic and tail gains on the main page), particularly if you have such a wide gap in HS as going from your AP setup at 1800 to a 3D setup at 2600 RPM. When tuning you high-HS gains for cyclic, start low (25 or so) and increase slowly until you start to see oscillations after quick cyclic inputs.

[siclic]

Hi Guys,

This is the setup I have on my T-REX 600N:-

Modified F3C Configuration
[section1]
PitchAgility=30
PitchGain=25
RollAgility=30
RollGain=25
YawAgility=35
YawRight=35
YawGain=100
[section2]
FixMode=3
ServoType=2
SwashPlateType=2
ServoDirCH1=-1
ServoDirCH2=1
ServoDirCH3=1
ServoDirCH4=-1
ServoAdjustCH1=-6
ServoAdjustCH2=0
ServoAdjustCH3=5
AileronLimit=50
ElevatorLimit=50
TotalCoefficient=55
PitchDir=-1
RollDir=1
YawDir=-1
TailPoint=-30
TailLimitA=80
TailLimitB=80
OptimizationDir=-1
[section3]
Acc1=125
Acc2=40
Acc3=100
Acc4=100
Acc5=25
Acc6=25
DeadBand1=40
DeadBand2=4
DeadBand3=60
DeadBand4=4
PitchGainD=0
PitchGainI=120
PitchGainP=80
RollGainD=0
RollGainI=120
RollGainP=80
SpinSpeed1=35
SpinSpeed2=35
SpinSpeed3=30
SpinSpeed4=30
TailCompsate1=0
TailCompsate2=0
TailGainD=25
TailGainI=40
TailGainP=80

The heli flies nicely with this setup . I do not fly hard 3D.

I have both the Tarot and NZ software and a Tarot Programmer and have a question about SpinSpeed. You will see that my configuration has values of 35 for SpinSpeeds 1 and 2, and 30 for SpinSpeeds 3 and 4. This differs from the F3C and Soft F3D defaults of 35 and I don't know what has changed these values. SpinSpeed is not shown in the software and the SpinSpeed in the Tarot Programmer menu appears to be the Yaw Rate as shown on the front screen of the software.

My Yaw Rates L and R are 35 for both Conditions 1 and 2.

Any enlightenment would be appreciated.

[Mikej]

I can't comment on the Spin Speed I'm afraid as I have those at default 35. A couple of comments though ... you still have your Dead Band settings at default of 40 and 60 - this can make the cyclic and rudder very dead around centre - most us us drop them closer to 10 or so (some even lower), secondly your Ail, Ele and Total coefficient settings of 50, 50, and 55 are a bit low - these will reduce the resolution of control that the FBL unit has. You should get better behaviour if you move the servo balls in a hole and reset the collective and cyclic settings.

[siclic]

Hi MikeJ, thanks for your input. I originally had the cyclic / collective ball links at 14.5 mm on Futaba S9255 servos when the heli had the standard flybar setup. I changed the head for an RJX FBL, using the bog standard T-REX swash, and I now have the servo balls at 10.5 mm. That's as close as I can get them without the links binding on the servo shafts and I still have bags of pitch range with the 50, 50 and 55 coefficients.

I had read about reducing the gyro deadband but thought it best to leave well alone as I'm relatively new to FBL. I also have 4 x 450 T-REX clones and I have recently converted 3 of those to FBL with Tarot Gyros and, following your comments. I'll now try lower gyro deadbands on them all.

[cofl1001]

Originally Posted by InFocus

Blade 450 3D, copter-x fbl, tarot head, stock 420 motor, Align 3g blades
Using the program box

Tail P:80 I:50 D:30
Accel L/R: 125
Decel L/R: 25
tail deadband RC: 60
tail deadband gyro: 4
piro speed l/r: 40
tail limit a: 123
tail limit b: 118

Roll/Pitch P:80 I:82 D:15
accel 125
decel 55
swash deadband rc: 40
swash deadband gyro: 4
roll/pitch agility: 40
aile/elev limit: 57 (about 7.5 degrees of cyclic deflection)
collective range: 57 (about 12degrees of collective deflection)

TX is a DX6i.
TX gyro setting: 68%
TX: DR/Expo setting 100%/25% (for rudd, elev, aile)
TX: throttle curve: 97-96-95-96-97

It took me a bit to finally get the heli working really well, although you can see I really didn't deviate too much from the stock settings.
The thing that threw me off for the longest time was FFF and light 3d was great, but I had some slight drift or wobble at hover, because I thought the swash was level, but in fact it wasn't. The fbl would 'try' to keep it right, but if I had the gains high enough to compensate for the un-level swash it would have other bad tendencies.. Anyway, with the mechanicals now correct, hovers are dead still, hands off even for 5+ seconds, and stationary piros are dead on.

Also, it very much likes the higher head speed, thus the reason I posted my throttle curve.

So, you checked the swash for level-ing it was ok, but after the wobbling you checked again, and found it to be not level-ed ?
Maybe I have the same issue. My heli wobbles in all directions in hovering mode, and since using the default settings, I dont know if my training gear on induces some additional vibrations ?

[astrecord]

Originally Posted by beenflying

Align 500EFL Pro
Align 425D 3G blades
500MX motor (12T slant pinion/134T slant main)
Align 70A ESC (using Internal BEC)
HobbyKing HK28013DMG Mi Cyclic servos
Fitec FS9357D Tail servo
Tarot ZYX FBL gyro (mounted in the frame)
Aurora 9 Tx and Optima 6 Rx

Video: http://www.rcgroups.com/forums/showp...&postcount=830

Cyclic servo arms: Align metal blue, inner hole (18mm)
Tail servo arm: 10mm

Cyclic Expo = 40%
Tail expo = 30%
Dual rates = 100%

Collective range = 57 (+/-12 degrees)
Pitch roll limits = 65

Cyclic Pitch & Roll:
Agility = 45
Gain = 40
P = 80
I = 80
D = 30
Accel = 125
Decel = 55
RC deadband = 50
Gyro deadband = 4

Tail:
Yaw rate = 40
Gain = 100 (Tx = 28)
P = 80
I = 50
D = 15
Accel = 125
Decel = 25
RC deadband = 40
Gyro deadband = 4
Cyclic comp = 0
Collective comp = 6

hi there my friend can i used this same setting on my 500esp with a spectrum DX 7s with zyx-s