450 Trex 450 Pro DFC Set Up Problems- Help on Set Up!

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Nl Henderson

Member
I got a trex 450 Pro DFC flybarless last week and I am having trouble with pitch and aileron servos on the initial set up with the 3GX.

Im using a futaba tx (T8FG Super) with the 6208SB reciever.

I have leveled the swash plate and when I throttle up and down , the pitch servo is a lot faster than the aileron???? (don't move equally together).

Also, when I input left or right aileron the aileron servo(right side) is the only one moving. ( pitch/throtle servo does nothing).

Please note that I have not completed the whole 3GX set up. This is as far as I have gotten. is there a setting in the tx i need to change (mix??) or do I just need to finish the set up (end points/limits etc.)

All help is appreciated as i have been fighting this for a while!!

Thanks
 
Tony

Tony

Staff member
You will need to set your Tx to ccpm 120º 3 servo swash. I have no idea how to do that in that Tx though.

One thing that I"m wondering about is why you said with aileron inputs, you don't get any throttle movements? Your throttle shouldn't have anything to do with teh swash. Connected to your swash should be the aileron, elevator and pitch (or aux 1). CCPM mixing mentioned above will put the aux 1 servo in with the others and mix them together.

Also, when you are setting this heli up, you need to go into DIR mode. To do this, turn on your Tx, push and hold the button on top of the 3GX and plug in your battery. Once you see the green lights flash one at a time across the gyro, release the button. This will bypass the gyros.

Hope this helps.
 
N

Nl Henderson

Member
In DIR mode, the pitch servo outruns the aileron and elevator. They don't move up and down together at the same speed. The ail/ele servo do work at the same speed together.
When I enter normal mode, the only servo that seems to work properly is the elevator, the ail/ele servos are all out of whack, they both
work in different directions when moving the joy sticks.
 
Derek

Derek

Well-Known Member
you may need to reverse your servo directions to get them all going the appropriate direction.
 
N

Nl Henderson

Member
I did reverse the throttle servo and they move in the right direction. Although, if reverse the pitch servo (in either direction) it does nothing.

seems like the pitch/throttle don't work together
 
Lee

Lee

Well-Known Member
You say throttle servo. There is no throttle servo. Have you got the servos in the correct ports. Ail Elev and Aux1.??
 
stokke

stokke

Well-Known Member
Nl Henderson said:
I did reverse the throttle servo and they move in the right direction. Although, if reverse the pitch servo (in either direction) it does nothing.

seems like the pitch/throttle don't work together
Click to expand...

Throttle? There should be no need to reverse throttle channel. There are three channels which control the swash movement; Aileron, Pitch and Elevator. See that all servos are connected to the correct port on your Receiver. Pitch usually plugs into the Receivers AUX port.
 
N

Nl Henderson

Member
Im using the Futaba 6208SB, pitch servo plugs in to channel 3 and is in the right port. I have double checked all the wiring and they are correct. In normal mode the pitch servo does not work. in DIR mode it works but does not move smoothly with ail/ele servo
 
Lee

Lee

Well-Known Member
Have you tried changing the servos around or changing the suspect servo to another port. This will tell you if its the servo or the RX giving you issues.
 
N

Nl Henderson

Member
I did that (hook in to the rx only) all three servos worked correctly with each other.

Hooked back in to the 3GX - Same thing, pitch servo is out runnung the ail/ele servo.

Also, when pushing up on the elevator servo, the aileron is the only that moves down in conjunction, pitch does not move at all (down)

- - - Updated - - -

Travel thow on the pitch servo is alot more than the aileron, do I need to adjust throws on the pitch servo?
 
stokke

stokke

Well-Known Member
If it works correctly when using only the Rx, then it should work correctly while in DIR as well. Is it so that when hooked up through the 3GX, the pitch servo does not work at all?

- - - Updated - - -

All your throws (servo travel adjust) should be at default; 100-100.
 
Tony

Tony

Staff member
What firmware are you running in the 3GX? You may want to upload a stock firmware to reset anything that may have been changed. Also, check your endpoints of all servos and make sure the 3 on the swash are the exact same. If one is lower (I'm suspecting the pitch), then that will cause this issue. Also, while you are setting this up, make sure your dual rate is at 100% and your expo is INH or whatever it was that your tx says. That way you don't have anything interfering with the travel and everything is linear.
 
N

Nl Henderson

Member
Thanks for all the help - The problem was that I had the throttle servo mapped to the pitch.

Got that all fixed and took a first flight. I had bad tail wag with the gyro at 65%

Had to dial it down to 50%. is this ok, or is it to low?? Also, when I pitch up hard and then hover, i get just a tad of wag in the tail.

Im not real keen on dialing/tuning these helis in. All advice would be appreciated.

And, I get just a little vibration on spool up (just before mid stick) is this normal??
 
stokke

stokke

Well-Known Member
Good to hear you got out the kinks :D

If your tail gain ranges from -100% - +100%, then 50% might actually be a bit high. Usually you find a solid heading hold around 40%.

Strange behavior in flight or hover is often caused by an un-level swash. But figure out the tail before attacking this problem.

Vibration while on ground is perfectly normal, as long as it does not vibrate in the air.
 
N

Nl Henderson

Member
Got the gyro down to 40%(can I go Lower) - It helped out a bunch, but when i use rudder to the left or right real quick, and the stop it, the tail twitches a little left and right in real short increments.

Also - do you know what a good throttle and curve pitch setting would be for?
1 - normal mode
2 - idle up 1
3 - idle up 2
4 - idle up 3

I would really appreciate some numbers on these if you can help out.
 
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