450 V2 Pro Tail Wag

[The Tone™]

I got my heli set up at the model shop on Saturday. It was set up mechanically and the 3GX unit was set up on the bench, no PC. When tilting the heli the 3GX tries to self correct and seems to be working, but the heli wasn't actually test flown due to bad weather.

So I came home and I plugged it into my PC for the first time and found that it was running V1.1. So I updated it to 1.2, and the software thinks it is a Trex 500 - 600, but I left it alone and didn't change anything as I want it test flown. The 3GX still tries to self level so I can only assume that's still working.

I finally tried to fly it today for the first time and built up the courage to try and lift it off the ground, when I got a few inches up the tail wagged terribly so I landed it and flew my mCPX around instead as that doesn't scare the crap out of me.

What should I do?

Should I plug it back intot he PC and tell it that it is a Trex 450 and click on the begineer button and try to fly again, or should I just go back to model shop and wait for a test fly?

To be honest I am a bit baffled by the 3GX set up, but I'm soaking up information like a sponge thanks to you guys.

Oh, and I did my first figure of 8's today. GO ME!

Any help would be very much appreciated, thank you.

[Spork01]

Definitely change the heli type to 450 on the 3gx via the pc software first.

check the tail grip bearings as many have them bad out of the box.

check the tail gain and try lowering it

[ctyankee]

Originally Posted by Spork01

Definitely change the heli type to 450 on the 3gx via the pc software first.

check the tail grip bearings as many have them bad out of the box.

check the tail gain and try lowering it

+1 on the Tail grip bearings. It is remarkable how little drag on the bearings will cause tail wag. I fought that one a while myself.

[The Tone™]

I have read about those bearings before, I might aswell change them then for sake of a few quid. Does anybody have a part number please? There are sooo many.

I think the tail issues are a set up problem. I am just getting my head around it but after messing about with it all evening my brain is a bit fried. I'm using a JR DSX9 and the LED on the 3GX goes green if I keep the Gyro Gain setting abover 52%, any lower it goes red. When it red I can use the tail properly, I move the stick a little, the rudder moves a little, I let go of the stick and it centres. When it is above 53% and has a green light it seems to have a mind of it's own and I have no control over it.

[350Z_Al]

When it's above 53% the tail should still move side to side when you move your rudder stick, it will just not re-center. If you rotate the heli, you should see the tail move to one side, if you rotate it the other way, the tail will go to the other side.

[The Tone™]

Originally Posted by 350Z_Al

When it's above 53% the tail should still move side to side when you move your rudder stick, it will just not re-center. If you rotate the heli, you should see the tail move to one side, if you rotate it the other way, the tail will go to the other side.

Ah ok, so it IS working then. At the risk of sounding like a right noob though..... How do I control it in the air if it doesn't recentre and react how I want it?

[350Z_Al]

Originally Posted by The Tone™

Ah ok, so it IS working then. At the risk of sounding like a right noob though..... How do I control it in the air if it doesn't recentre and react how I want it?

Think about this:

With the tail centered there is no left or right thrust coming from the tail. The heli's main rotors are causing the heli to want to rotate all the time. If the tail linkage remained centered, the heli would just spin out of control.

What your tail is doing is actively trying to keep the heli from rotating. If the gyro senses the heli rotating in one direction, it will compensate by moving the tail to provide thrust in the opposite direction to keep the heli straight.

If the gyro senses no rotation of the heli, it will keep the tail at the spot that it is currently at (not re-centering) because that is the amount of thrust required to keep the heli from rotating at that given time.


Make sense?



As for your problems, after updating the 3GX to 1.2 and changing your model to 450, you may need to set it up again.

Check all your tail linkages for any kind of binding.

Not sure what your gain values are now, but IIRC my 450 is in the 60-70% range depending on my flight mode.

Another thing we need to look at are your throttle curves, were you flying in Normal mode or in Idle-Up? What is your throttle curve in the mode you were flying in?