Problems with tail gyro on Align 3G

[santomotion]

Hi,

I'm new to FBL, I've a Trex450 3G that can't make it work.
I've gone through the manual and the swash plate (pitch and roll) seem to work ok (after adjusting it I've done the checks and it corrects in the opposite direction as is supposed to do).
The problem comes when I try to adjust the tail gyro, I go into gyro set up mode but I can't set the limits. When I move the radio stick right, the tail servo moves ok but when I move it left the servo moves as if head lock was on (the servo travels slowly all the way to the end regardless of how much you move the radio stick).

Under normal operation (not in set up mode) the gyro does not correct the tail when I move the heli (yaw) by hand and seems not to react to changes on the sensibility settings on the Radio (Spektrum DX7).
The servo moves fine when moving the radio stick, so I don't think it could be a servo problem.

On which channel should the gyro sense lead be on? I'm using a 6ch Spektrum receiver.

Do I need any special cable to update the 3G unit?

Thanks a lot in advanced!!

Cheers!

[Made2Fade]

If its not letting you set the limits then its probably because your out of its range. Get in range by going in or out on the tail servo arm. How far out are you on the servo wheel/arm?

[Made2Fade]

On which channel should the gyro sense lead be on? I'm using a 6ch Spektrum receiver.

Cheers!

The Gear channel

Do I need any special cable to update the 3G unit?

Yes you need the usb dongle

[Made2Fade]

Trex 450 Pro build videos - HeliFreak

Set it up as per the GP750 gyro in those videos. Its exactly the same setup. In the video Bob goes on about being on the correct hole on the servo arm, how to do it and how it puts you in the sweet spot (and within range of the gyros limits themselves).

[santomotion]

Trex 450 Pro build videos - HeliFreak

Set it up as per the GP750 gyro in those videos. Its exactly the same setup. In the video Bob goes on about being on the correct hole on the servo arm, how to do it and how it puts you in the sweet spot (and within range of the gyros limits themselves).

Thanks! I'll have a look at the videos when I get home.

I think the tail servo is properly mounted, with the rod at 90deg and the tail blades centered.

I'm wondering why the servo tails does not correct at all

[coolice]

Hey.

The lone single gain wire goes into channel 5 (GEAR) on a 6 channel receiver.
Check your ATV values for this channel to, you should see a solid green light on the 3G to signal you are in heading hold mode and it should change to red when switched to rate mode.

It's probably not the case here, but I setup a 3G with a DX8 that had a dodgy rudder channel, basically when the trim was centered that channel wasn't in the monitor page. This stopped us setting the rudder limits as the 3G was still seeing a rudder input even when we'd set the slider to the right position.
Go into your transmitter menus and check the monitor screen to see that when all trims are centered that the control bars are also in the middle of their travel.
.

[Delarado]

The problem comes when I try to adjust the tail gyro, I go into gyro set up mode but I can't set the limits. When I move the radio stick right, the tail servo moves ok but when I move it left the servo moves as if head lock was on (the servo travels slowly all the way to the end regardless of how much you move the radio stick).

Mine does exactly the same thing? But ive been flying it without issue really. I dont notice any other problems, only that it doesnt seem to care how uch youve moved the stick when setting rudder limits...

[santomotion]

Ok, I'm going to go from easy to complicated... I'll check that everything is plugged in the right place:
There're two single wire cables going in to the receiver, is that normal? Ones I get home I'll check where everything goes and post it.

Could the reason for the servo tail not correcting any at all being the gain set to 0%?

What does ATV stand for?

Cheers!

[Delarado]

You shouldnt have any servos plugged into your RX at all.

All 3 cyclic servos and the tail servo should all be plugged into the 3g. The 3g then has single wire cables that plug into the RX. The only plug that goes directly to the RX is the ESC I think...

If gain is set to 0% then yes it wont self correct i dont think...

[santomotion]

Mine does exactly the same thing? But ive been flying it without issue really. I dont notice any other problems, only that it doesnt seem to care how uch youve moved the stick when setting rudder limits...

Does it do the same to both sides when setting up the tail servo limits?

[Delarado]

As soon as you touch the stick it just moves all the way till it hits the stop i think, unless you press the other way first. ill do it again tonight.

[Delarado]

mine is 3gx though, is yours the original 3g?

[santomotion]

mine is 3gx though, is yours the original 3g?

Is the original 3G

[santomotion]

I have just taken all the wires out and I´ve found what it looks like a voltage regulator between the 3G unit and the tail servo (DS520, a bit big for a Trex450).

Does the DS520 need that? I thought it would work fine connected directly to the 3G unit, any suggestions what is that doing there?

[santomotion]

I´ve been looking on the internet and it looks like the DS520 runs fine with 6v. Should I still use the voltage regulator?

●Coreless Motor Design for fast speed, high efficiency, and low power consumption.
●10 Bits signal resolution for smooth movements.
●Response time of 0.07s/60°. High strength composite alloy gears with high precision and durable structure characteristics.
●Aluminum alloy mid case construction for instantaneous heat dissipation, maintaining servo’s high efficiency.
●Supports digital & analog control signal.
●Powerful and precise servo suitable for T-Rex 500 CCPM cyclic and rudder servo use.
●Stall torque:1.9kg.cm(4.8V)
2.5kg.cm(6.0V)
●Motion speed:0.09sec/60°(4.8V)
0.07sec/60°(6.0V)
●Rating voltageC 4.8-6V
●Temperature range:-20°C~+60°C
●Dimension:35 x 15 x 29.2mm
●Weight:25.9g
●1520μs standard band