I just installed a spirit pro that I'm testing out on my goblin fireball, and I cant get the tail to stop wagging violently.

I removed a brain 2 mini which was working perfectly, so I know the tail is mechanically in good shape.

It seems like the unit isn't responding to my gain adjustments in the radio. When I go to the diag screen in the software, I can run the gain all the way down until it almost flips over into Heading hold+rescue mode, and the tail wag is exactly the same. It's a fast "gyro gain too high" style wag that gets worse in Idle 2. When I adjust gain in the radio, it matches the readout in the diag screen, but it doesn't seem to be changing in the unit.

Servo pulse and refresh rate are set correctly for servo....bk ds3005hv tail servo. 760/333 My travel limits are both around 170 or so in both directions.

Not sure where to go from here.

Hello,

first from all I recommend to put a longer servo arm or one hole further if possible. This will reduce too high travel that will be better for Spirit. So both end-points values will be lower.
In this way you will be able to increase Gyro Gain as well, hopefully without an oscillations.

Could you please tell me what value you can see in the Advanced/Rudder Delay and Pirouette Consistency? Correct configuration can help a lot.

Please check this page:
http://manual.spirit-system.com/index.p ... t#BK_Servo

Could you observe what the tail servo is doing when you spoolup the model without main blades? Does it react correctly? Can you observe some oscillations already on the ground when looking at the servo arm?

Please note, that for Spirit units noticeable higher Rudder Gain is needed than for Brain.

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Spirit System developer

Moving the ball further out to reduce travel and increasing gain seems opposite of what is done with other systems! I'll certainly give it a try though!

Thanks for the help.

Indeed, but in your case you are getting tail wag although there shouldnt be any. So I suppose the tail mechanics geometry is not optimal - this is also indicated by too high values for the end-points.
Normally there should be both between 90-120. So for too high limits you can also see warning in the software.

Gyro Gain difference should be noticeable approximately each 2-3%. Only if mechanics is super tight, the difference wont be visible and rudder will not work with probably any configuration (maybe only with Revomix). But you said it is perfect, so we have to suppose there is other issue.

The most pilots with Fireball found issues in the mechanics out of the box and after solving them the mechanics started to move smoothly. Then the performance improved dramatically.

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Spirit System developer

OK, I moved the ball distance so I'm getting about 100/100 on the tail travel, changed the delay to 4, rudder consistency is at 160. The wag is WAY worse!!!

Servo behaves normal on the bench/ground, but as soon as I'm airborne, all hell breaks loose! Severe wag. My gyro gain is set at 4. If I go any higher, it gets worse exponentially.

As I stated before, I had absolutely no wag on the brain 2. I simply removed it and installed this spirit pro to try out.

Oh, that is pretty strange.

With Gyro Gain set at 4%, the tail servo should do barely nothing when moving the model.
So near 50% it should react accordingly.

At the moment it look like the servo must move a lot even at mentioned 4%,

Are you able to visually compare if the servo response is similar to that one you know from Brain or it reacts significantly more?

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Spirit System developer

OK, I think i figured it out! I had a rogue setting in my TX. I setup a new model, started from scratch, and all is well.

How did you solve the problem? Please share