700E V2 tail blowing out

[devens]

I am having issues with my tail blowing out in fast backward flight when I pull into a big backward loop.

I am flying a 700E V2 with black vbar and V5.2
2150 HS
BLS 251 rudder servo
105 Radix tail blades
710 Radix V2 main
CC 160HV in fixed RPM mode

My rudder throw in VBAR is within tolerance but right at the maximum.

My native gain for the rudder is set at 89 in my radio. I was thinking about trying longer tail blaides. Like Edge 115's. I read that helps the trex tail. Another potential solution is more head speed and I would need to regear. I suppose it is possible that I am boging the head and causing it but I am not doing a tight loop and I am being carful with the collective while testing it.

any help would be appriciated

Daren

[MrMel]

Start with raising Acceleration parameter.
Perhaps gain too.

115mm will do it if nothing else but your parameters are low.

[Ah Clem]

"I am having issues with my tail blowing out in fast backward flight when I pull into a big backward loop."

I have a V1 with an 8900G on the tail, KBDD EE 104mm Tail Blades, and a Blue Full-Sized V-Bar with 5.1 Pro.

Tail Gain is at 69.
P-Gain is 78.
I-Gain is 69.

I have not tached it, but it definitely does not bog-RPM is quite constant.

The tail holds beautifully in large backwards, outside loops (one of my favorite things to do and this machine will move quite fast, backwards, especially on the descending portion of the loop).

When you stated that "native gain" in the radio is "89", what did you mean? If memory serves, the gyro gain setting in the transmitter does not change the gain on the V-Bar, if the V-Bar is the Pro version of the software (it does in Express). Only the computer or control panel can change the rudder gain (again, if I recall, correctly).

[KC36330]

Originally Posted by Ah Clem

........... the gyro gain setting in the transmitter does not change the gain on the V-Bar, if the V-Bar is the Pro version of the software (it does in Express). Only the computer or control panel can change the rudder gain (again, if I recall, correctly).

with bank selection set to Aux-->gyro gain you adjust tail gain from the transmitter aux channel (gyro gain in the transmitter)

[devens]

Mr. Mel

My gain is set to 108 in Vbar! That seems high since 120 is max. The acceleration was at 55 and I lowered to 45 after reading the "popup guide" in the vbar. P and I are a 75 for a basline starting spot as you describe in you tail setup vid.

I assume you mean to raise the P&I gains when you say raise the gain?


AH Clem,

The gain is adjustable from my radio in V5.2. I do this for quick tuning so I don't have to "plug in" to the vbar.


I could just buy the tail blades but I rather get ti working with the software if possible and spend the $40 else where

[MrMel]

Raise acceleration as it affects a lot

[Ah Clem]

KC36330 and devens,

Thank you, I did not know that about 5.2 or bank switching (on the tail gain from the TX).

Always learning from this forum.

[fstclyz]

Guys,
If I'm not using the tail gyro gain on the TX in 5.2 pro (only through the software), do I "inhibit" gyro gain on the TX? or should I just click on the Bank function-gyro gain so that I CAN adjust the gain on the TX? I think I'd prefer this.

I'm new to Vbar and just went from the free software to Pro and unsure what to do with the tail gyro gain on the TX. As of now, the TX settings don't affect/change the tail gain in the software (atleast the bar/slider doesn't move when changing the gain on the TX).

Thanks,

CD

Originally Posted by Ah Clem

KC36330 and devens,

Thank you, I did not know that about 5.2 or bank switching (on the tail gain from the TX).

Always learning from this forum.

[K2Freak]

I believe the current best practice is to run 115 tail blades on the 700E, even at higher headspeed like you are running, OP. Many, many threads over the last several months have related the very noticeable difference between the two sizes. Definitely works better for me...

[Rexaholic]

+1

Edge 115's fixed my problems. I had it pretty close anyway before the switch but now it holds solid as a rock!