Backward drift with 3GX

[WolfE]

This summer I have built up a 600 Pro with the EFL 3GX V1.0, but during the first flights a backward drift has become noticeable in my hover speed. I could eliminate this drift by a BeastX pad and a slight increase in the balance speed. After a slight crash I rebuilt the heli and made the new update to the 3GX V1.2. For the first flight I used the settings from Leon. At hovering no drift was noticeable, but during the sport flight an always stronger backward drift has become noticeable. If I reverse the rapidly drifting helicopter again hovered in front of me, the drift was less and less, until the drift was no longer noticeable. Then again flight and the whole drift problem repeated itself.


I've tested everything: No Sub-trim is used, 3GX relocated, same Swashmix results for Aileron and Elevator, new bearings of the engine because of vibrations, center of gravity tested slightly top-heavy, neutral and slightly tail-heavy. All measures did not help, my 600 EFL is always drifting backwards with the 3GX V1.2.


Last Action: A downgrade to the 3GX version V1.0. Then first flight and suddenly there was no drift anymore. Today I made two more flights, no longer drift detectable.


Why does my 3GX with the V1.2 not work correctly?
Is my 3GX defective?
Is the 3GX V1.2 not suitable for sport flights?



Regards Wolfgang

[Cra-Z-1]

Thats a great question...I've got Ver 1.2, as well, and am seeing the exact same thing you were. Although annoying, its not so bad, it will cause me a crash. I notice it the worst when I land and spool down. After the blades stop spinning, I can watch the swashplate very slowly inch back toward neutral. It prob takes 1 to 2 minutes to return to level. It always starts out nice and level, and after performing a couple of loops, I notice a backward drift, and it stays that way the whole flight.

[dct]

I also have had backward drift from day one on my 550 V2 3GX..
I have used 1.1 and 1.2 software update with ALL STOCK or default setting in software except I have changed EXP to 0 in software because I have been told to do so ,,, if using EXP in TX...
I posted this problem here...https://www.helifreak.com/showthread...344814&page=11 #211 and got a answer here #212 .... I have sent my 3GX in for warranty ... And have gotten a new one back.... I have not done a test flight yet!!! But will try one soon ...
I will let you know how it works out...!

[Gerald11]

I got the same problems (I'm on v1.2), including a drift to the left - followed the threads here on HF and elsewhere, tried all proposed solutions - but nothing helped.

I just didn't try to step back to v1.0 (don't know where to get v1.0 from).

I keep the fingers crossed for your new unit - if it works I know what to do.

Gerald

[dct]

To all,,,,, the new 3GX DID NOT STOP the tail from slowly falling ...
Or drifting backward in hover or falling slowly in forward flight!!!!!
So we all need to post this problem for all to read and maybe find a fix???
My settings,,,, are all the same in my first posting here #211...
https://www.helifreak.com/showthread...344814&page=11

Leon Luke,,,
Please help me if you can?
Trex 550 V2 3GX
Setup withV1.1 and now V1.2 on both software from day one, the tail keeps dropping very slowly !!
Now I have been flying for years and know how to setup fly bar helicopters..
And the swash is level the CG is even a little nose heavy and still the tail comes down in hover or in FFF...
I have tested it with different nose down trim 4 clicks and still the tail will fall very slowly ....
The servos are good ....
The Trex only has 70 flights on it..
It has been doing this from the first flight...!
I have even lengthen the elevator servo rod a little to make swash a little high in the back to see if that would push the nose down....
But it still drops the tail as if it was tail heavy.....
It is nose heavy....!!
I'm sure... !
I was waiting for this new update to see if it would solve this problem ??
It didn't .....!!!
I run a DX7 with sat plugged into the 3GX ..
Running 30% exp only ,, and using stock setting in new software with exp set at 0 in software .
Gyro is set at 36 in software... on gyro ..
What Do I need to change?(( Or try???)) (( Bad 3GX ??? ))
Thank you.
Dan T

[ReadyToCrash]

i also have the same problem. i use v1.2 niw, but had the same issue with 1.1.
the heli takes off perfectly straight with not backwards drifing at all, but during the flight develops this anomaly...
honestly this is not bothering me that much anymore, but i'd like to have it solved.

[bad007]

I noticed with 2.1 if you tip the helli and hold it there the swash goes back to level even if it's still tipped. My 3G doesn't go back to level when tipped and I don't remember 1.1 doing that either. My new Velocity drifted back slghtly also but just discovered by laying a straight edge along the top of the 3GX it was tilted back quite a bit. I leveled the 3GX unit and have yet to do a test flight. With the 3G I used to set the helli up level, initulize it and made sure the swash was still level. My 500 with the sensor on the tail boom didn't set level and tipped the swash. I leveled the sensor and the swash stayed level and the annoying drift went away.
I'd say COG is criticle with the 3GX esp. since it seems most hellis are tail heavy.

[WolfE]

I sent an email with the 3GX error description to the German robbe support.
The text was identical to the text in my first post in this Thread.




I received the following reply.

If you have set identical values for roll and pitch with the3GX 1.2 version and drifting occurs, send the 3GX to us.




I will send my 3GX to the support

Robbe, is the German general importer for Align products




Greetings Wolfgang

[Cra-Z-1]

Originally Posted by bad007

I noticed with 2.1 if you tip the helli and hold it there the swash goes back to level even if it's still tipped. My 3G doesn't go back to level when tipped and I don't remember 1.1 doing that either. My new Velocity drifted back slghtly also but just discovered by laying a straight edge along the top of the 3GX it was tilted back quite a bit. I leveled the 3GX unit and have yet to do a test flight. With the 3G I used to set the helli up level, initulize it and made sure the swash was still level. My 500 with the sensor on the tail boom didn't set level and tipped the swash. I leveled the sensor and the swash stayed level and the annoying drift went away.
I'd say COG is criticle with the 3GX esp. since it seems most hellis are tail heavy.

Without having tried levelling that thing out yet "first", I'm gonna say that I'll bet your on to something there...The table that I run my setup on is a little high on one side, and I know for a fact that when I zeroed the swash out to setup in "DIR" mode, the nose is toward the high side. Gonna get a minute to try my new 3GX out today. If I get this with the brand new unit, I'll level the heli first, and go from there with a new setup.

[dct]

I sure don't know ... But IMO the only thing the 3GX sees.... Is level at half stick on swash....!!! Even if the helicopter is in a horizontal position laying on it's side??

[Cra-Z-1]

Originally Posted by dct

I sure don't know ... But IMO the only thing the 3GX sees.... Is level at half stick on swash....!!! Even if the helicopter is in a horizontal position laying on it's side??

It definately seems like that IF the unit needed to be perfectly level during setup, that they would make a pretty big note of this in the software instructions.

[ReadyToCrash]

hey guys,
i don't think the problem is the table not being perfectly level, or the unit not settling perfectly level on the heli. i tried this out already and it didn't solve or changed a thing.
i even went further. i tilted the table on the other direction so i could see a dramatic change in behaviour in flight and absolutely nothing happened.
it seems to me we are missing a crucial point: does your heli drift backwards right after the take off? mine doesn't. it only starts drifting after a few maneuvers or after a few min of flight. it says to me the problem is the fbl unit itself, not the set up. the unit simply isn't that good as it should be. after it gets warm or after the current/voltage drops a little bit it just starts working bad. a guy here in helifreak said this backwards drifting is a "feature". i think it is.

[Siliki]

hi , may be you can have a look at these posts...
https://www.helifreak.com/showthread.php?t=356585
https://www.helifreak.com/showthread.php?t=362393

it may help...
if you r on futaba , have a check if your cyclic afr are the same on nick and roll... ??? that could be a way ....
let s try , here the weather is too bad to try!!!
have good flights.

[dct]

Update..
Going to try Leon Luke setting to see if this will help???
Rudder Delay Command ..
With testing.... My 3GX will only go to 10 % down from 17%
Next...
Aileron Sensitive 93 % with pots turned all the way up and slider set at 70%
Elevator Gain... 93% with pots turned all the way up and slider set at 70%
This is as good as I could get my 3GX to these suggested settings for the 550...!!
If this doesn't fix the tail dropping slowly in hover and in forward flight, I think I will try and send the 3GX BACK FOR THE SECOND TIME!!!
IMO the stock settings in 1.1 and now 1.2 should work without having to change all these settings!!! I do have a good CG and have also tried nose heavy ...!!! So I am VERY disappointed in this 3GX....!!!!!
This is the second 3GX I have in my 550 ... Doing the same thing!!!
Will the NEXT ONE WORK???
See post here ,,https://www.helifreak.com/showthread...25#post3496125
#260

[Cra-Z-1]

Boy do I feel your pain, dct...Same exact thing with mine; second brand new unit. 3GX=

Nuther link...same issues..

https://www.helifreak.com/showthread.php?t=356585

[bad007]

Well mine did the same unless I dialed in froward trim. This was a new helli with just two gallons run threw it so I decided to recheck setup. It had even collective and now for some reason I ended up with +15 and -13 and the horns where a tad bit high. Lowered the horns, reset 0deg. with the links, double checking with FB paddle gauges and checked from both sides and after roataing the head 180 and raise the head speed from 2100 to 2150 rpms and the drift is gone. It was real bad before. COG is still a tad tail heavy.

[jmackey]

Backwards drift is a 'safety feature' to protect the pilot during nose-in landings.
Just Kidding

After all of the trouble-shooting I have done with 3GX (3 different units on 3 different helis) the one common denominator is the 3GX unit or something in firmware common to all 3 versions I have tested. I experimented with extremes in CG, trims, subtrims, recalibrated and updated my radio, adjusted endpoints or not, firmware versions 1.0, 1.1 and 1.2, setups from stock to Leon Lukes (best flying setup in 3GX I tried by far), precisely balanced my complete RTF head and tail assemblies on the shaft, all kinds of other tweaks, you name it.

3GX is not bad for sure. I have several hundred flights on 3GX with TREX 450 and 700 helis and it never failed in flight for me. It has been a solid performer for the money. Other than the backwards drift, I have had several light blade strikes after autos. Feels like 3GX is over compensating some cyclic inputs when headspeeds are dropping. This is what I learned to fly with, so it's all I knew until my first flights with VBAR about a month ago.

For me the bottom line with 3GX (IMO of course, your results may vary...):
It is what it is.

It isn't bad, but doesn't have that locked-in simulator feel either.

Jay

[dct]

Originally Posted by dct

Update..
Going to try Leon Luke setting to see if this will help???
Rudder Delay Command ..
With testing.... My 3GX will only go to 10 % down from 17%
Next...
Aileron Sensitive 93 % with pots turned all the way up and slider set at 70%
Elevator Gain... 93% with pots turned all the way up and slider set at 70%
This is as good as I could get my 3GX to these suggested settings for the 550...!!
If this doesn't fix the tail dropping slowly in hover and in forward flight, I think I will try and send the 3GX BACK FOR THE SECOND TIME!!!
IMO the stock settings in 1.1 and now 1.2 should work without having to change all these settings!!! I do have a good CG and have also tried nose heavy ...!!! So I am VERY disappointed in this 3GX....!!!!!
This is the second 3GX I have in my 550 ... Doing the same thing!!!
Will the NEXT ONE WORK???
See post here ,,https://www.helifreak.com/showthread...25#post3496125
#260

Update.....
I did some test flights on these settings...(( Going to try Leon Luke setting to see if this will help???))
NO DIFFERENCE !!! 3GX still drop's the tail ,,,! Very slowly in hover and forward flight!!!
Can someone post a link to some Align company in the USA that might test this 3GX ...??
Thank you.
Dan T

[XYZVector]

I am having same problem, this is my only complaint about this otherwise awesome flying helicopter.

[th0rg0d]

Send it back and request a coupon of equal value towards a BeastX. If enough of you do this, they might fix the problem.


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