Hello,

I have a Goblin 380 and the Spirit FBL and I haven't been able to sort out some tail wag that I have no matter what headspeed/tail gain I run, even with the speed up tail pulley.

So today I did some tinkering with the Spectrum Analyzer and found something interesting. My tail (Z Axis) is showing massive vibrations (316-350), and vibrations of about 63 on my X Elevator axis, with 9-15 on my Y Aileron but when I disconnect the tail belt from the main shaft it goes below 20 on all three axis.



So I'm pretty sure the vibrations are in the tail, but I wanted to check with you guys and see how you would proceed and what I should be looking for.

Steps I've taken:
1) Remove tail blade grips - No change
2) Remove Pitch slider - No change

Because of how this heli is designed, if I remove the tail shaft I can't rule out bearings, the supports that hold the bearings, or the tail pulley.

My guess is that it is the tail shaft, but I just want to make sure I'm on the right track and the figure out the best way to trouble shoot the problem.

Thanks,
Nathan

I found the issue. I had installed SAB's belt tensioner and while spooling up I was looking over the heli and noticed that the tensioner was jumping around a bunch, so I took it off and everything is below 20 on the whole heli.

Even though it's been a lot of trial and error, I'm really enjoying the Spirit. Can't wait to get it fully tuned!

Perfect you have found it.

In case of any question feel free to ask.

_________________
Spirit System developer