Tail servo positioning - need help

[Maverik]

Hi there,
First of all I want to mension than English is not my first lengauge so please exuse my gramar mistakes in advise
Second – that is my first heli so … I am not very experiensing with helis
I am using:
Spectrum DX7
Beam E4 kit – asembled as manual says
Scorpion Comander 55A V2
CSM SL720
Futaba 9254 /servo arm is ~11mm and is 90 degree from its base for setting up with gyro Mode0/
1.
I mount servo so I have 8 degree tail blade pitch to the left (so nose will go to right). In that position tail slider is not in his full travel middle position and when I try to make gyro travel adjustment for tail servo slider hits tail base and there are not enough compensation to separte slider from base. To othe rposition (slider to tail rotor) everything is OK. Ignoring left travel adjustment I have limited slider move for full ruder stick comands both directions (gyro Mode0).

2.
I mount servo so slider is in his middle position. Here everything is OK with gyro travel adjustment. In gyro Mode0 I have full slider travel according to rudder stick, BUT … I have ~8 degrees tail blades pitch in wrong direction (nose go to left).


I am starting to thik that I must change direction of tail toror rotation, but this is totally wrong according to Beam E4 manual.

I am stuck in this problem and I cant solve it alone. Please help me to set up this thing right. 10x in advice


P.S. Gyro manual says to set ATV to 100% on TX but Spectrums manual says 145% ATV for rudder to be set ... which i must to follow?
P.S.2 Is the servo arm 11mm alright?

[rspblake]

Martin,

Welcome to the forum, strangely over the last week or so, we have been talking about this..offline.

We are trying a model with the rotation in the wrong direction as a test, just to see if the tail has any improvement over the standard setup with the limited tail end point..

To be honest the tail even though limited seems better or as good, than most 450 out there, right hand tail being limited seems still to be ok..maybe its the way its driven..or the result of the head being better..

I have checked other forums and it seems it has never been talked about!

My concern running backward is if the limits are not checked, it could rub the brass sleeve slide not locktite in the slider correctly, it could come undone. (rotation with the threads)

If all things correct it should be fine..

The norm is to drive the tail into the wash of the main blades, this will not be the case running backward, I have asked a few people about it and if run tail away, what the effect will be.
Seems just hovering and straight climbs or inverted is the only area it could be effect, if at all being more and more we are never in one orientation for long enough.

Talking with Russ Deaking and then Angelo's its seems that its only rate mode this offset really matters, it is more important in hold to get the overall travel set as close to 200, being it could be 90 one side and 110 the other, but stressed 50 /150 is to wide and drop a hole but also if you ended with 90/180 to reduce the throw on the larger side slightly.

It seems in hold that the gyro can sort itself, if the point are sensible.

This was a long conversation with both and very helpful thanks guys.
I kinda skipped most of it

I think the Cy G works better when you set to the center of the shaft(servo posistion via G view) and read the max throw limit on the shortest side and work out the amount to center then equal it out on the other side,. again its dont care about the dreg on the pitch it seems, so from that they all seem to work the same on the same idea.

You will need to run the servo arm as small as possible, increase the throw rate via the gyro..over 90% min on the CSM, I am sure to get the best.. sure someone will correct me on that..

So I feel there is room for improving the tail better than we have, but in its standard works does perform excellent any way..

Rob

[3dbasher]

Martin,

Welcome to the forum, strangely over the last week or so, we have been talking about this..offline.

We are trying a model with the rotation in the wrong direction as a test, just to see if the tail has any improvement over the standard setup with the limited tail end point..

To be honest the tail even though limited seems better or as good, than most 450 out there, right hand tail being limited seems still to be ok..maybe its the way its driven..or the result of the head being better..

I have checked other forums and it seems it has never been talked about!

My concern running backward is if the limits are not checked, it could rub the brass sleeve slide not locktite in the slider correctly, it could come undone. (rotation with the threads)

If all things correct it should be fine..

The norm is to drive the tail into the wash of the main blades, this will not be the case running backward, I have asked a few people about it and if run tail away, what the effect will be.
Seems just hovering and straight climbs or inverted is the only area it could be effect, if at all being more and more we are never in one orientation for long enough.

Talking with Russ Deaking and then Angelo's its seems that its only rate mode this offset really matters, it is more important in hold to get the overall travel set as close to 200, being it could be 90 one side and 110 the other, but stressed 50 /150 is to wide and drop a hole but also if you ended with 90/180 to reduce the throw on the larger side slightly.

It seems in hold that the gyro can sort itself, if the point are sensible.

This was a long conversation with both and very helpful thanks guys.
I kinda skipped most of it

You will need to run the servo arm as small as possible, increase the throw rate via the gyro..over 90% min on the CSM, I am sure to get the best.. sure someone will correct me on that..

So I feel there is room for improving the tail better than we have, but in its standard works does perform excellent any way..

Rob

sounds about right... not got that far yet... good idea though i'll be running my tail in reverse from day one i'll let you know how i get on

[Maverik]

I have just adjusted 5 degree tail pitch and successfully passed all gyro set-up procedure. It seems to me that 8 degrees is too much for gyro’s travel adjustment length(maximum compensation from gyro for left/right stop point). I hope that 5 degrees will be enough and is in the range of the Quick-trim system …

[Maverik]

After first test hoover:

1. WOW Beam E4 fly almost alone ... far-far away from flying of HoneyBeeFP ...

2. The 5 degrees from previous post was .... only 1 So in Mode0 I even dont dare for now to hoover it. I only get it light on its training kit and heli gets crazy piroeting tendency so i decide not to push it furder.

3. After readjustment of servo location and double check 5 degree tail pitch i have Throw limit 1 136% and Throw limit 2 50%. Tommorow i wil try it again ...

www.youtube.com/watch?v=xWiF11T_DtI

[rspblake]

Martin servo arm length?
What servo are you running?

[Maverik]

Futaba S9254 with ~11mm servo arm
Tommorow i will try 9mm/7mm servo arm, now i am almost sure that the arm lenght is making this mess.

You will need to run the servo arm as small as possible, increase the throw rate via the gyro..over 90% min on the CSM, I am sure to get the best..

10x Rob, you says it perfectly clear but ... it takes some time to me to be given meaning and realise that is better to have more frames then more speed.

[Maverik]

I have shorten servo arm and now i have Throw limit1 - 154% and Throw limit2 - 96% (+/-23 degrees maximum tail blades pitch), ~ -8 degree pitch in centered rudder stick (Mode0), but slider haven't reached its maximum position for Throw limit1 side(154% is maximum alowed for throw limits). Is this setup OK, or i must continue with adjustments to have full travels (-23 / +35 degrees tail blades pitch).

[pieter]

sorry i cant help my friend but WOW the tail is a work of art

the tail is sometimes the hardest part to get right, sometimes even a very minor amount of trim can send it off but just persevere and it will get there

[scallybert]

We are trying a model with the rotation in the wrong direction as a test, just to see if the tail has any improvement over the standard setup with the limited tail end point..

I don't know if what I'm going to suggest is possible, but it looks like it might be from the manual.

The tail does look like it wants to have the slider moving right for more thrust tail to left. Which is what your reversed rotation will do.

Another approach might be rotating both tail grips 180deg (also reversing baldes in grips so they effectively stay in the same orientation).

You'd also need to reassemble the tail pitch links to deal with this, as the offset is different. (However it looks like you can do this.)

This should reverse the tail action. ie slider moves right to make blade tips go left, and give more thrust tail to left.

[Maverik]

I don't know if what I'm going to suggest is possible, but it looks like it might be from the manual.

The tail does look like it wants to have the slider moving right for more thrust tail to left. Which is what your reversed rotation will do.

Another approach might be rotating both tail grips 180deg (also reversing baldes in grips so they effectively stay in the same orientation).

You'd also need to reassemble the tail pitch links to deal with this, as the offset is different. (However it looks like you can do this.)

This should reverse the tail action. ie slider moves right to make blade tips go left, and give more thrust tail to left.

I am not sure, but ... maximal pitch of 23 degrees seems to me enough, may be increasing pitch more then 23 will not provide furder trust.

[rspblake]

Martin reduce the 154% down in the gyro limit on setup to around 115% it will be more than enough.. that would be 96/115 the rest you would not need.

Just try see how it feels..

[mattie-lodge]

Hi Guys,

Interesting subject this. I recently have bought a Beam E4 and after flying it 5 or 6 six times decided to sell my 450 over it.

After a short time I too noticed that the tail geometry was not quite right. As always CSM gyros have to be set up in Rate mode to hover hands off. This will maximize your performance of this gyro. I did this, then went though the quick setup routine to set the end points up. I must have flown it about five or so times with setup, and had a feeling that I could get a little more from the tail. Over the last last year I have learnt a fair bit about tail setup so I was on a mission to improve this one. I also had limits of 155 and 55 so I tried to seek away round it to solve this problem. Lee (3DBasher) was the one that came up with the idea of twisting the belt through 180 degrees and turning the tail blades round. This would give a reverse tail rotor direction but would put the tail slider in the middle for hover hands off. I did this mod, and after reversing the gyro, rudder channel and resetting the gyro flew it again. Hovered it in rate mode then once again followed quick setup and away I went. My limits are now 104 and 105. Perfect!!!!!!!!.

So what was the flying like. Well, its better for sure not a massive amount but better, probably what is most noticeable is the stops are crisper and the hold seems better as well. Disadvantages:- Now the tail blades are going into the main blade rotor wash. Personally in flight I have seen no adverse effects of this so I'm not too bothered and also it was pointed out to me that to keep an eye on the brass sleeve on tail shaft doesn't come unscrewed from the pitch fork.

My setup is CSM 720 Align DS 520 servo ball 7.5mm out (first hole on the futaba 6 Star horn)

I have now done about 15 flights with it in this config and reckon the tail is now very good.

[scallybert]

I am not sure, but ... maximal pitch of 23 degrees seems to me enough, may be increasing pitch more then 23 will not provide furder trust.

Could be - but if people are reversing the tail rotor direction - what I'm suggesting is an alternative that may have advantages. (eg no tendancy for tail to unscrew, blades not going in tail wash.)

If I had an E4, I might actually try it...

[Maverik]

Today weather was almost calm ... only 20km/h wind ...

The tail is OK in HL mode and in piruets, but in Mode0 ... left pitueting and with half turn of pushrod right pirueting. I must to find someone more experienced then me to make quick-trim instead of me ...