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›››› 611 Single Tail Bounce Problem :-[ (
Posted by "Cam" on 06-02-2009 04:56 PM:
I've been flying my eRaptor 90 "EMAX" for a few months now and finally decided on the right motor and set-up so I'm getting used to it and getting my flying more finely tuned as well.

I had a 601 on a Raptor 90 about four years ago but that simply worked so I never bothered with the settings!

My EMax tail will bounce once when stopping from a right-pirouette.

It also does this other thing where the tail will accelerate beyond the normal max piro rate after you unload the collective - but that might be the gov.

The settings I started with were from Raptor Technique (I think) they looked pretty standard. I've listed all my 611 settings below so you may be able to diagnose what the trouble is.

BLS 251
95mm NHP Tails
The linkage ball is on the outside hole on the servo arm

RUDD L115% R115%
GEAR +72% -100%

G25N 5.5V
G38A 5.5V

LmtA 121%
LmtB 111%

AVS 105%
Fmod 3D
Mode CMT
Trk 0%
D1DA 0%
D1DB 0%
D1IA 15%
D1IB 25%

NCGA 130%
NCGB 105%
ACGA ***%
ACGB ***%

G:1A 50%
G:2N 43% - I think this is the total gain (I started with 37%).

I want the stop & lock to be solid when I centre the stick.

I think I've got the gain up as high as it will go - it's at 100% on the Tx. If I turn it up any more the tail will sometimes wag sharply and briefly when in fast forward flight.

I didn’t like the handling with any acceleration delay (D1DA/B) and I can’t tell the difference in changing the tracking (Trk%)

Also my links seem to have gotten loose very quickly - they're quick UK ones and it's only had maybe 20 flights.

EMax V2

Posted by Kader on 06-03-2009 08:24 AM:
Hi , it is not about "fine tuning", but first thing which I noticed on your setup are different limits (LmtA and LmtB) each other. For 611 there is recommended, that both limits are the same and abov 120 % . To reach this there is often have to shorten the servo arm, most often third hole on servo arm works well.


Posted by duceduc on 06-03-2009 08:50 AM:
I thought anything above 100% atv equal on both side is fine or pretty close to equal.

Duc S
Do It! Do It!™

Posted by Kevin Dalrymple on 06-03-2009 11:39 PM:
The linkage ball is on the outside hole on the servo arm
I can see that it is, but how far out is it? It should be 14-17 mm. If it is 12 it will not feel solid.
Posted by "Cam" on 06-05-2009 02:12 PM:
It's more than 12mm - I need to measure it.
Yes I can make the ATVs equal by adjusting the pushrod length, but I doubt that will remove the bounce.

The tail is very solid and if I centre the stick softly the tail is fine, if I centre the stick quickly it will give a single bounce.

EMax V2

Posted by "Cam" on 06-12-2009 04:00 PM:
The servo ball's at 16mm from the center of the servo hub.

EMax V2

Posted by "Cam" on 07-21-2009 09:05 PM:

I changed the length of the pushrod so both limits are the same and 118%, and the tail will still do a single, large (maybe 15 degrees and fairly slow) bounce when stopping from a right-pirouette.

Again All the settings are in the first post and:

G:1A 50%
G:2N 43% - I think this is the total gain (I started with 37%).

I want the stop & lock to be solid when I centre the stick.

I think I've got the gain up as high as it will go - it's at 100% on the Tx. If I turn it up any more the tail will sometimes wag sharply and briefly when in fast forward flight.

EMax V2

Posted by Kevin Dalrymple on 07-22-2009 12:42 AM:
G:1A 50%
G:2N 43% - I think this is the total gain (I started with 37%).
Did you fly with 37% in G:1A? your gain with a 50 size machine should be around 37% (on the gyro screen). Normal mode will be different. Not sure what you tried the gain % in with Head hold on.
Posted by "Cam" on 07-22-2009 01:09 AM:
It's a Raptor 90 electric.

Both rate and lock on the Tx are 100%

The GY601 and 611 are a the few points in the hobby that are still a grey area to me. Too many gain settings and I still don't get how they effect each other.

EMax V2

Posted by Kevin Dalrymple on 07-22-2009 01:48 AM:
Try this.
Posted by "Cam" on 07-22-2009 11:14 AM:
OK I've read that ^ and all my settings agree with JK's.

I had found that I get a way faster piro rate in FAI mode and the tail can stop very abruptly, although still has the single bounce.

I can imagine that the torque of the electric coupled with loading the motor may cause tail issues but this bounce happens even in gentle stall turns at zero collective and even in the hover.

I'm flying at 1950 RPM with 710's and 95's.

I tried 100 and 105 tails with the same results.

I am wondering if I should turn my gain back down to 37% (as JK and the manual say) and then try bigger tails.

Maybe go back to FAI mode and turn the piro rate down as well.

EMax V2

Posted by TMoore on 07-22-2009 03:34 PM:
Does the heli exhibit any rotation while in rate mode?


Delayed Response Operator Not Engaged
AMA SECTION 336 = Good
Drones = EVIL

Posted by Eco8gator on 07-22-2009 07:27 PM:
What gyro tape are you using? It doesn't look like your using the stock tape setup(including metal plate).

I'd start there.

Xera Motors
Thunder Power

Posted by "Cam" on 08-15-2009 09:12 PM:
I am using th stock tape and the metal plate!

Umm - I don't know if the heli drifts in rate mode - I never use rate mode except for when I'm carrying the heli!

Do you really think drift in rate mode coudl be the problem?

Also I'm running a headspeed of 1900 and this is with 95mm tails, although bigger tails do the same thing.

EMax V2

Posted by f penfold on 08-16-2009 11:59 AM:
cam try adjusting delay and tracking these are the settings to change stopping rate

I know I used lock tight why did my head explode

Posted by "Cam" on 08-16-2009 12:15 PM:
Ok Thanks. I’ve tried changing the delay before and I find increasing it makes the problem worse. But I’ve never touched the tracking because, although I’ve read the manual countless times, I don’t understand what tracking actually does.

Delays are currently at

D1IA 15%
D1IB 25%

- I thought you had to have some to save the tail gears?!

I am also wondering about the AVS setting – am I right in thinking this is a bit like gain – but it’s more like how much gain the gyro applies with the amount of tail stick?

AVS 105%

So many settings, and wind & rain again :-[

EMax V2

Posted by Dr.Ben on 08-17-2009 06:01 AM:
First, while Jason's settings were applicable when he wrote them ages ago (2/2005), they are not nearly as applicable for the 611 with a BLS251. Thus the agreement of your settings to Jason's are in no way a predictor of the success of your set up.

You're using the wrong delays. You want D1DA and D1DB, not the ones you've adjusted which do nothing to reduce the bounce. You preserve tail gears and reduce the bounce by slowing the electronic return of stick to center. I can't see how increasing the delay for a right stick input return to center makes the problem worse as you noted in one of your earlier replies.

You'll not want the gain in AVCS mode to be up at 100%. Try around 50% for a starter. Arbitrarily placing the gain at 37% fails to take into consideration the uniqueness of each installation and often deprives you of the staggering performance capability of BLS251.

FAI mode has markedly more agressive stops than 3D mode. Keep this in mind.

The outer-most hole on the Futaba 6 pointed star works exceptionally well in most applications. Larger wheels increase the mechanical gain in the system, which is more difficult to precisely manipulate than electronic gain. I'm no proponent of a tiny little servo wheel, but excessively larger arm radii don't work well either.

The tracking menu is effective for dialing out this problem. The manual's verbage can be followed as written for which way to adjust the value depending on which piro stop is affected. Your issue will require adjusting the tracking in the negative direction.

Also, note that all GY series gyros work best when trimmed mechnically. For those of you reading this for interest who have GY520's, this is especially important for that gyro.

Let me know if you continue to have problems.

Ben Minor

Peak Aircraft/Team Minicopter Team Futaba Team Kontronik USA

Posted by NoLuckChuck on 09-22-2009 01:12 PM:
Can anyone tell me if the GY611 is as capable as a GY520 or the newer gyros (JR370/JR770/Spartan/Align 750/Mini-G)? I can get a good deal on a 611 with servo. I will use it on a T-Rex 500ESP and possibly on a 600ESP in the future. I am not into 3D yet, but will do in the future. Thank you
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