Wobbly Cyclic on a Compass 3D+ and 3GX

[atomiccomp]

I have a Compass 3D+ with a 3GX on it. The head is an RJX 50 size and the 3GX is on 3.1 and mounted on the battery tray (flipped upside down)

When I do rainbows or aileron tic tocs the heli wobbles on the cyclic and the pitch seems a bit spongy.

Has anyone encountered this? I have no idea what to adjust on the 3GX.

Other than that the heli flys great.

[coolice]

I have a Compass 3D+ with a 3GX on it. The head is an RJX 50 size and the 3GX is on 3.1 and mounted on the battery tray (flipped upside down)

When I do rainbows or aileron tic tocs the heli wobbles on the cyclic and the pitch seems a bit spongy.

Has anyone encountered this? I have no idea what to adjust on the 3GX.

Other than that the heli flys great.

Hey buddy.

What sort of head speed are you running? Normally a cyclic wobble indicates that the cyclic gain pots are a little too high, however if rotor rpm is dropping during your rainbow this will upset matters and it could be through a lack of rpm.

On V3.1 there is no pitch boost option like you have on V4 and above, so a soggy collective response could also be down to rotor rpm and or collective pitch range.

This is a 500 class model isn't it? My 550 settings file may work well on this model and help smooth out the 3GX for you.
.

[atomiccomp]

Hey buddy.

What sort of head speed are you running? Normally a cyclic wobble indicates that the cyclic gain pots are a little too high, however if rotor rpm is dropping during your rainbow this will upset matters and it could be through a lack of rpm.

On V3.1 there is no pitch boost option like you have on V4 and above, so a soggy collective response could also be down to rotor rpm and or collective pitch range.

This is a 500 class model isn't it? My 550 settings file may work well on this model and help smooth out the 3GX for you.
.

Cheers,

Its a compass 3D plus which is a 600 nitro. Headspeed seems constant and is running 2000-2100 rpm, I originaly had the 2 pots set to 12 oclock and tried 2 oclock and it was just the same. i will try turning it down. I have tried V4 however I then had a constant tail wag, however I spoke to Raj at align trex today and he said the tail needs setting up in rate mode first which I never did. So armed with that info I will try V4 again. Going to get rid of the wobbles first before I upgrade. It seems worse on the stops during the tic tocs. I will try reducing the 2 gain pots.

Thanks for the response.

[coolice]

Evening Mate.

There is no excessive vibration on the model? Are you using the stock mounting pad and where is the 3GX mounted on the model? These can cause problems sometimes.

What servos are you using also?

Raj is correct, V4 needs to be setup in rate mode by adjusting the tail pushrod to hover hands off. Also you need to set your tail gyro delay to large/small heli, but make sure no delay value is set so that it stays at zero percent. To do this push the rudder stick in the direction of delay type you want, green led for large heli in this case, then leave the 3GX on this delay parameter to time out and reset. If you press the rubber button to move onto the next step the delay isn't stored, there is a bug in the system, you need to leave the 3GX to time out on the delay LED for it to store the setting.
This combined with the rate mode setup removes the bounce back/over-shoot on yaw commands.
Also in the PC software reduce the rudder lock gain value from the default value of 70% to 45~50%, this allows you to run a higher Tx based gyro gain before wag sets in.
.

[atomiccomp]

Evening Mate.

There is no excessive vibration on the model? Are you using the stock mounting pad and where is the 3GX mounted on the model? These can cause problems sometimes.

What servos are you using also?

Raj is correct, V4 needs to be setup in rate mode by adjusting the tail pushrod to hover hands off. Also you need to set your tail gyro delay to large/small heli, but make sure no delay value is set so that it stays at zero percent. To do this push the rudder stick in the direction of delay type you want, green led for large heli in this case, then leave the 3GX on this delay parameter to time out and reset. If you press the rubber button to move onto the next step the delay isn't stored, there is a bug in the system, you need to leave the 3GX to time out on the delay LED for it to store the setting.
This combined with the rate mode setup removes the bounce back/over-shoot on yaw commands.
Also in the PC software reduce the rudder lock gain value from the default value of 70% to 45~50%, this allows you to run a higher Tx based gyro gain before wag sets in.
.

Hi Dude,
The 3GX is mounted on the battery tray where it meets the front frames. Its a fair way from the mainshaft! Apparently this is where compass recommend you install the FBL controller and or sensor. The tray is turned upside down so its flat. The mounting pad is the stock one. Vibration is normal I would say for a nitro, all engine and drive parts had new bearings last week and I use Align DS620 on the cyclic and a 650 on the tail. The servos came with the model which was flybarred originally.

I will let you know how I get on with lowering the pots.

Thanks again for your help.