500pro 3GX setup issues

[mhills51]

Just flew my pro for the first time today and it was super twitchy. I have two 250's and it makes them look like coaxes. Also as it would slowly go higher and I would input a little less collective it would start to drop quickly and not start to rise until I inputted a lot of collective. The motor not bogging down at all. Seems like the gyro would raise the collective and after I corrected it It took some time to rise back. I set the speed control for fixed end points at 0, 50, 85, 90, 98 which compared to my FB500 sounded and looked correct. All the guys around me fly v-bar or beast and don't seem to know anything about the 3gx.

[DesJardins]

Did you calibrate the ESC & then complete the entire DIR set-up while at center stick?

[leedawg]

Also I would just set flat throttle curves you will get much more consistent collective control. The gyro does not move your collective around either it just controls the cyclic and the tail. It is normal to have to put in a fair bit of collective when the bird is coming straight down without any forward movement takes alot more than a hover to counter that momentum and gravity then you back off on the collector once you have stopped the decent to maintain hover or you will start to climb again. Remember the 500 is much heavier than your 250 so its going to behave a little differently however it should be much slower and not as twitchy feeling on the controls as a 250 id do what the above poster said go through the DIR completely on the setup and calibrate your end points on the ESC...

[mhills51]

Yes I calibrated the speed control and like I said this is my second 500 just first FBL. I have five 450's, two 250's Two scale 450's with a five blade heads using copterx fbl controllers.

That is what has got me baffled on this. I do seem to have lots of bad luck with bad electronics and yes a poor set up fbl controller will screw with your collective so to say it won't effect it is incorrect sense it controls all the servos.

[Steemo]

If your using V1.2 this helped me tame the twitchiness of the 500 and 450 with 3GX. It is mostly about your Tx setup so make sure you have done the initial setup by the book then try the info in my posts here.
https://www.helifreak.com/showthread...=344042&page=3 read through from post #28 to end of P4
https://www.helifreak.com/showthread...06#post3713206 summarized

with regard to collective... are you using a 0-100 pitch curve?

[mhills51]

Yes on the pitch curve 0-100 also have my swash at ail +60, ele +60 and pit +30 to get 12 +- on all controls. I had upgraded to V2 before I programmed it knowing that I would have to reprogram it all if I upgraded later. Will look into the links thanks! Using Futaba 7C fasst s-bus rx.

[Steemo]

hope it helps

[jschenck]

My swash mixes are at 40/40/45 for ail/ele/pitch - getting ~8 cyclic and ~12.5 collective - it's silly fast. Put a pitch gauge on there and go through the setup again. Mine flew almost perfect off the bench. I'm running V2.0 software on the 3GX which I like better than the 1.x software.

[DesJardins]

I'm -/+12~pitch, 9~cyclic.
Never been plug into a PC and it's solid on v1.2 after the DIR with 5% TX expo

[mhills51]

Thanks guys, I just set it up per the directions and with 12/12 degrees on both. It's a flybar thing lol! I will try turning it down. I need to go back and reprogram the whole thing anyway. #2 servo could not get 90 with arms so I had to use trims before set up to get it 90, but on start up that channel slams down past the collective so I need to take it to the other notch and trim it the other direction.

[DesJardins]

Your using Sub trim during DIR only correct?
Not "trim"

[poconnell]

With version 2.0, use a computer to lower the flip and roll rates. I went from 50 to 40 one each and it made a HUGE difference.

[mhills51]

Yes, sorry sub trim to bring the one up before set up. I will change the rates in the computer and try that. Beautiful out side, but 30 to 40 mile gust. Not to good for testing lol!

[mhills51]

I think I may of found one of my problems and maybe a lot of problems others are having with the 2.0v. The set up directions are different. Now it calls for setting up no more than 8 degrees for pitch, elevator, and collective. The old directions call for 12. No wonder it is twitchy and anyone that upgraded and didn't change this would be in the same boat as myself. As for my servo that was off I just adjusted the link and kept the sub trim at 0.

[DesJardins]

I believe the v2.0 calls for a pitch range of 10-14 (depending on your preference) and 8 degrees of cyclic...
Below was from the v2.0 thread



Here is a copy of the 3GX V2.0 manual
The software animations recomend the following:
__________________________________________________ _______________

1.Using 600EFL PRO as an example, the recommended pitch range±12°, maximum pitch range for advanced pilot shall not exceed ±13°.
2. Adjust the maximum collective pitch using the transmitter's swashplate mixing function (pitch swash AFR). Do not adjust individual servos endpoints through the servo ATV/AFR function. Should any changes made to the endpoints or subtrims on the transmitter in the future, the 3GX flybarless system initial setup must be performed again.
The recommended collective pitch range for various T-Rex helicopters:
(Collective Pitch Settings)
◎T-REX 250
With Emphasis On Stability : 12°
With emphasis on agility : 14°
◎T-REX 450
With Emphasis On Stability :12°
With emphasis on agility:14°
◎T-REX 500
With Emphasis On Stability :10~12°
With emphasis on agility :12~14°
◎T-REX 550
With Emphasis On Stability :10~12°
With emphasis on agility :12~14°
◎T-REX 600
With Emphasis On Stability :10~12°
With emphasis on agility :12~13°
◎T-REX 700
With Emphasis On Stability :10~12°
With emphasis on agility :12~14°

[Daddy B]

Originally Posted by mhills51

Thanks guys, I just set it up per the directions and with 12/12 degrees on both. It's a flybar thing lol! I will try turning it down. I need to go back and reprogram the whole thing anyway. #2 servo could not get 90 with arms so I had to use trims before set up to get it 90, but on start up that channel slams down past the collective so I need to take it to the other notch and trim it the other direction.

Just get the arms close on the setup, and do not mess with the subtrims. Once you go into DIR mode, then make your subtrim changes.


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[ManilaIce]

DaddyB or anyone, is there a difference in doing a subtrim in DIR vs outside DIR? Second, should i use swashpate leveler during DIR and not outside DIR?

[mhills51]

All adjustment of this kind need to be made in dir. If you make adjustment outside dir without hooked to the gyro all your adjustments will be wrong and if you make adjustment with the gyro hooked up they will be wrong because the gyros will be on and trying to make adjustments of its own. Also if you make any adjustments in dir you will need to reprogram the gyro to update the adjustments....Man thats a lot of adjustments lol!

[Daddy B]

Originally Posted by ManilaIce

DaddyB or anyone, is there a difference in doing a subtrim in DIR vs outside DIR? Second, should i use swashpate leveler during DIR and not outside DIR?

I dont know, but I set the subtrims from zero anytime I go into setup mode. I write the values down so I can change them quickly. I follow the manual (in EngRish, lol) to the letter, and my helis fly likes dream. I love the 3gx. I would be glad to help you out ifi can. PM sent.


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[Steemo]

Dir mode switches off the gyros, you will not get an accurate servo centre point if every time you move the heli the servos move.
So yes, always position your servo arms and set sub trims while in DIR mode.