Hi guys, First post here.

Background: I bought the Spirit for my "new to me" Gaui X3 (converted to X3L) heli. It's a try-head/tri-tail heli swinging 380mm blades.

I did post on HF about my maiden experiences today, but figured joining this forum would be a better resource in the long run.

Spirit setup went well, and the maiden flight today was good, barring a tail issue. After playing around with the settings, I've pretty much dialled out the tail issue, but what remains is some bouncing on left rudder input, (tail to the right). Now having a try-tail swinging 3 x 67mm tail blades over the stock 2 x 62mm blades might contribute to the low gyro gain settings I ended up settling in at, but thought I'd ask here to get some feedback. I ended up with 37% on my IU which is a rather low HS for a 450, (about 2100rpm) but is pretty nice for smooth 3D on 3 blades actually. On IU2, about 2250rpm, I'm at 32% gain. The tail was holding well and I put it to the test with FF backwards inverted flight and there was no blowout.

It's slightly soft on stopping on Right Rudder inputs, but there is still a hard stop followed by 2 or 3 tiny bounces on the left rudder input.

The tail endpoints are 88 and 96, if I remember correctly and the tail is super smooth mechanically.

First off, is this low of a tail gain surprising or expected for the type of tail I am running.

Secondly, how do I go about reducing the bouncing on the left rudder input, and increasing the soft stopping on the right rudder input.

I tried playing with Rudder Dynamic, increased Rudder Delay from 8 to 15 to 20, Piro Consitency, and nothing really seemed to make much of a difference.

I have further Spirit questions, but don't want to confuse the issue with too much yet, so will leave it at that for now.

Hi and welcome in our forum!

First from all, please check our Servo list - http://manual.spirit-system.com/index.p ... Servo_list

There you can find parameters for your servo(s).

Then the best thing to start is to verify how your mechanical center is configured for the rudder.
For gaui I recommend slight angle 3-4 degrees so thath the slider is closer to the boom.

Your gyro gain is quite low, so for this reason I recommend to try to use a shorter servo arm if it is possible.

Values of Pirouette consistency and rudder delay are important to make it work well.
Can you attach your settings so I can check it?

In the manual, problems and solutions section you can find possible solution by reducing limit on the side which is too agressive - usually right end-point. Tri-bladed rudder has too much of mechanical gain so this is also reason why the difference is more visible. But everything can be solved.

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Spirit System developer

Thanks Tomas. I am happy to hear your optimism at getting this solved. I gotta say that even with this tail issue, I left the field yesterday with a smile on my face. I loved the way the X3 felt in the air and part of that was likely due to three blades on the head, but most was likely due to the Spirit. I could never quite get my BeastX to feel like the sim, but I instantly felt at home and confident with the Spirit flight characteristics you had advised me to start with. I'll definitely be converting my Protos over next. Especially now that a DS-14 is on it's way to me.

I was using the ballpark servo recommendations from the manual so was a bit high at 8 on the Rudder Delay. I see the the Servo list has 2-5 recommended for my KST 565X. Should I start at 5 and work my way to 2 or vise versa?

My rudder centering was done with zero pitch on the tail blades with the servo at 90deg. So I should shorten the pushrod slightly so that 90deg on the servo ends up pulling the pitch slider slightly inward to give an approximate 3-4deg of pitch on blades? Do I inderstand this correctly?

I'll move my servo ball inward a hole as well.

I had tried various combo's of Delay and Piro Consistency. (8, 12, 15 & 20 for delay, but didn't go lower) (160, 150 & 140 for Piro) Currently set at 12 & 160, but will drop delay down to 2-5.

Just wanted to update on what I've done since coming home based on your suggestions and on HF too.

I did some digging to see what distance most Gaui X3 owners set their tail servo ball from servo arm centre. Most were between 7 and 10.5mm. I was at 14.5mm. I had 2 holes closer than the one I was using; the closest being 8.5mm and the middle 11.5mm. I figured I'd try the 8.5mm one based on the 7-10.5mm range others were using. Once I got hooked back up, and went to set the Rudder Endpoints, the Spirit Software told me the Endpoint range was too high. It was over 150 and I could see binding where the pushrod exits the X3's frame near servo.

I then moved the ball to the middle position at 11.5mm, which wasn't flexing the pushrod toward the servo as much, and then eyeballed 3-4º on tail blades with the pitch slider toward the boom. Then with the tail servo centered, I moved the ball link inward so that the 3-4º was locked in with the rudder servo in center position.

From there, I set endpoints and are in a happy zone of 120 and 132, and backed off slightly more than I did last time after binding is induced, (maybe 1mm on each side from binding).

I bumped up the gyro gain back to 60% from 37%, set Rudder Delay of 4, Rudder Dynamic to 7, and Piro Consistency to 170.

Am hoping that these changes make that tail perform as it should now. Uploading images for your perusal. Thanks!

Good job. I am sure that you are on the right way.

In any way, it is important that there is no bending of the push rod - even slight flexing (at the ends) can cause a worsened performance. But it is still better, than when servo arm is too long.
Yes, for this helicopter it should be somewhere near 10mm.

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Spirit System developer

Hi Tomas,

I was able to get out for 3 more flights today and my 60% Gyro gain was perfect for my IU1. I bumped to 65% to see if I could get away with that, but wagged through banked turns.

That said, the tail issue on left rudder inputs persisted. Still pretty much the same as last time. I dropped the Right endpoint down to match the left side at 120 each and it was no different. I lowered it all the way to 100 and still no real change. I have the Dynamic at 5, and it's not terrible. but it's still an abrupt stop on left rudder inputs that stop hard and bobble on that one side, while the other side remains considerably softer.

I was at Left = 120, Right = 132 but I've dropped the Right to 100 and have kept it there. The Dynamic is at 5 and I experimented with Piro Consistency from 150 to 180 and 180 seemed to maybe make it worse, and 150 felt unstable for it's ability to hold in backwards flight.

Thoughts on where to go from here?

Have you tried dropping the left value?

Nope. But can try that.

I had a thought while laying in bed though.

I am running gearing that is calculated for 2630 for the middle rpm on Mr. Mel's. He lists 2529rpm for the best performance so I entered 2500 in the Max rpm filed within the Spirit Gov. From there, I'm running IU1 at 85% which is somewhere just above 2100rpm. Could my lowered headspeed be a factor worth exploring here?

I also thought I should inspect for any grip play that may be causing the slightest flex and instability under the hard stop of tail to the right.

Interesting thread.

Although my X3 is two bladed (not three like the OP), I do recognise the slight bend in the tail pushrod.
I also see a slight bounce on hard tail stops.

I'm using a 9mm horn on the tail and that does indeed give a bit high numbers.
Left: 169
Right: 131
Besides the slight bounce it flies great with 61% tail gyro gain.
(Using 360mm main- and 68mm tail blades.)

So this thread triggered me to change the tail servo horn.
I've found one which gives me 10.5mm distance.
That changes the limits to slightly better numbers.
Left: 135
Right: 112

Lowered the tail gyro gain from 61% to 55% (just a guess) because I now have slightly more mechanical gain.
Now we wait for a test flight!

The tail servo pushrod still is slightly bend.
I don't think you can make that perfectly straight.
That will make the servo horn too long and give too much mechnical gain.

Added my settings for anyone interested.

Hello,

there is one simple test you can perform, which can give you immediate overview if the tail mechanics is absolutely OK.

1. Unmount all blades.
2. Disconnect servo arm from the tail servo.
3. Start the motor to apporx. flight RPM
4. Carefully move with the push rod from end to end and verify what force is required to move with it.
This will tell you how smooth the mechanics really is when flying.

Important is that there is no point, where something is bending and causing additional friction. Usually these issues are bigger in highr angles, so the tail can't react fast enough even that servo is fast.
Even friction from ball linkages that is present on some new kits can cause bigger troubles. It will unfortunately always result in performance degradation.

Usually the first bad phenomenon if the mechanics is not OK is observable tail hunting during hovering.

Can you share your whole settings, please? You can attach here 4ds settings - no need to do any screenshots. You only have to save the file in the Backup tab.

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Spirit System developer