Strange tail vibration - need some suggestions

[Ace in the hole]

My logo 10 has developed a tail vibration that is giving me fits trying to track it down. It started after some minor tinkering with gearing and such. I even reverted back to pre-vibration set up and still no stopping the vibration.

Basically more noticeable at higher head speeds. I have tried adjusting everything and here is where it gets weird. Say I have a headspeed of around 2200 (pretty hot I know, I am thinking of tuning it down some more to give me more flight time), if the gyro is set at 40% gain it is a really fast vibration. Turn the gyro down to 20% and you get a mild tail wag, go to 10% and it is still there but becomes a gentle sway but also doesn't hold the tail for anything. I tried mounting the gyro in 3 different locations with 2 different types of foam tape- 1 of which is original futaba squares. Even tried a second gy401 gyro that I have and same thing happens. My conclusion right now is that my gyro is not happy with something I just can't figure out what.

Any suggestions?

I have checked:
double checked blade balance with a koll rotor pro- main and tail
bearings thru out tail and main shafts
gears
tail belt
even built a second whole tail from main gear on back
re-routed wiring several times

[OICU812]

Do you have the plastic rear pulley? If so check for small chip missing out of it, this oddly enough has been a common culprit for what you describe. I went through the same exact expereince and changed everything, until I thought well this is the last thing to change sure enoough that did it. Under close inspection under a big magnifying glass the pulley had a rediculous small chip of plastic out of it and that was all it took. Now I certainy am not saying that is it 100% but sure an easy thing to swap out to try if you have a new one handy. Now forgive me if your rebuilding of tail included this replacement, I just know this is an overlooked item alot of times it seems.

[Ace in the hole]

Thanks for the suggestion Shawn, yes I do have a plastic tail pulley. I am open to anything right now, so that will be replaced.

I refuse to let this defeat me! :arggg:

[WillJames]

Try different tail blades?

[Lorents]

Interesting tip Shawn! It would be cool if thats the solution.

Not sure if its the safest thing to do, but I usually take off the main blades and balance the tail blades with tape by spooling up while holding my hand on the boom to feel if the vibrations increase or decrease when I place tape in different positions. Keep your nose away from the tail blades while doing this and set your gyro in rate mode...

[Ace in the hole]

Thanks guys, yes I did try different tail blades. Lorents- never done that but it's worth a try too. I will keep trying things one at a time till I find it.

[OICU812]

Ace, you figure out your issue yet or how is it coming along? :dontknow

[Ace in the hole]

Just got the new parts and put it back together, have not had a chance to get it back in the air yet. It being winter and all, I am kind of at the mercy of old mother nature.

[OICU812]

Oh tell me about it, blizzards here and worse winter I have ever seen here in my life. I now have over 6 feet of standing snow on my front lawn, and I am not kidding! Last 4 years in a row I have not even seen over a inch, this year is like the friggin arctic crcle, it really sucks arse. :(

[jamesotron99]

You'd think it would be okay here - supposedly the middle of summer. I haven't flown once yet since about november!

[Klinger]

Awesome weather here guys, best flying weather lately, maybe you guys should move to sunny queensland :glasses2: :Stay

I had a small vibe in my horizontal fin and it disappeared when i put on a new open type tail setup. I couldnt see anything wrong with the tail box i replaced :?