450L tail moves back and forth quickly no matter the tail gain

[hoofenshnoz]

Hi 450L people,

So I have recently swapped my 3GX out with a GPRO and have also replaced the tail assembly after a crash. The tail servo is on the outer most hole as previous and mechanically everything seems very fine now. Although the helicopter is flyable I get a fairly fast tail shake back and fourth no matter which tail gain I use.

At this point I'm just looking for areas I should look at. Although the tail is all new, the transmission umbrella gears inside the fuse have not been replaced (but they are not stripped), could perhaps they just be worn out? The tail pitch slider seems smooth and tail assembly seems ok to me, anything I should look for?

I am totally new to GPRO but I've set up the 450L exactly to the instructions for the GPRO and set it to 'small hell'. Would this shake be perhaps a GPRO problem, if so what should I try?

Thanks everyone!

[alyon187]

Can you make sure that adjustments are actually working from your tx? Meaning that if you change the gain in your tx does it change in the software? Is your tail output shaft straight? Bearings in the tail good facing the right direction? Also your ball might be too far out, I dont have a gpro or have ever used one but I believe you need the ball to be closer to the output shaft. If its the ds525m I think it needs to be in the middle spot on the servo horn. I would imagine one of these would be the likely problem.

If all is correct ypu can try and lower your P and I gain in the tail part of the software.

[hoofenshnoz]

Hey thanks for the reply. I know for sure the tail gain is working as it works in the software and I can physically see the gain being changed when I shake the tail on the ground side to side and adjust the gain while watching the tail pitch slider compensate. I will definitely check bearing direction. Weird thing is that on the GPRO when you set up tail endpoints before binding even on the innermost hole you're only getting to about 40-50 points out of the ideal 100 points of resolution. Thanks for the help

[hoofenshnoz]

SOLVED!
Turns out the pitch links had some thread lock on them and they were a bit too tight. Cleaned them out and was a bit more clean with my loc-tite...problem solved!

[alyon187]

Yah that'll do it, it helps if instead of putting the locktight on the screw is to put some on a toothpick and put it inside the hole itself so this doesnt happen.

[hoofenshnoz]

That's exactly what I did! Live and learn