V911 problem, suggestions?

[FoeDog]

Hello everybody. First post here. Just got into the RC copter thing a few weeks ago with my son....got a couple of 3 ch copters (s107g and s109) and are having fun.
Decided to try a 4 channel and picked up a V911, 99% of flights will be indoors.
Arrived yesterday.
Having trouble getting it to hover in place.
I know I'm a novice, but no matter what I do, or how I adjust the trim, once I get it in the air, it starts revolving in a counter-clockwise circle, anywhere from 3-6 feet in diameter, fairly fast. The nose stays fixed in the same direction (lets say north), but the copter will not hover in place at all. Eventually it will get too close to a wall and I have to set it down.
No hard crashes, but a few soft ones.
Too windy today to try it outside, but I did take it out to the 2 car garage to have more room, but no change. I've checked all the linkage parts, everything is in place and clean.
I saw in another thread about the flybar being too tight may cause this, so I loosened it, but still no change.
As it flies now, it's impossible to control it indoors without hitting something.
Not sure what the difference is between 'crab trim' and 'directional trim' is either.
Help!

[Mally99]

Hi Foedog..welcome to the forum . It sure sounds like the heli has the toilet bowel effect (TBE) . As you said , there is a recent thread here on that problem , I think the problem was something binding on the rotor head / flybar or a cracked part .

`Crab trim` ? What`s that ? Crabs move sideways..sounds like ? Have you/ can you switch off `crab trim` ? If so , is there any change ? I have a Solo Pro 260a..similar to the V911 and any hovering issues on mine are usually caused by worn links / ball joints ...oh , and crashes !

Maybe try re-binding the tx to the heli . Hope this helps .

[FoeDog]

Thanks for the quick reply Mally.
I'm going to try re-binding a little later today when I have some 'me time'.
This heli has 4 digital trim buttons. Speed trim, direction trim, forward/reverse trim, and crab trim. there is no on/off for the trims, other than being centered, or neutral.
It also just about always takes off to the left, no matter how I compensate the directional and crab trim.
Hopefully the rebinding will help.

[Mally99]

You may have to set throttle trim to zero and stick at zero to re-bind the heli .

I think all helis take off to the left , to some degree..mine do . Sometimes I use right aileron to stop this , but more often than not I just pop them up about a meter and go from there .

[Atomnguyen]

My v911 does the same thing. Check the tail motor. The back of mine came off the housing after a crash. Pushed it back in and flies better. Waiting on replacement now. Hope this helps.

[FoeDog]

Thanks again everybody.
But I'm still having no luck. Checked the tail motor and it is secure in its housing as it should be. Went through and checked all connections to make sure they were moving freely or tight as they should be. I re-binded it as well (a few times over the course of test flying)....still no change. Had the whole 2 car garage for room, but as soon as I got it up about 6 feet (a couple of meters) or so, it starts revolving in that counter-clockwise circle. Again, adjusting trim made no change. Starts spiraling pretty fast sometimes too.
Toilet Bowl Effect indeed.
As it is, it is impossible to fly indoors, (which is where I bought it to fly). It's a calm evening, took it outdoors but that wasn't much fun, watching it spiral around.
I don't know, I must say I'm pretty disappointed with it. tried calling XHeli.com customer service but it was busy all day. (1 phone)?
If anybody has any other suggestions I'd be happy to try them out, but as this V911 stands now, maybe its trying to tell me where it belongs....

[RaymondMatlack]

Thanks again everybody.
But I'm still having no luck. Checked the tail motor and it is secure in its housing as it should be. Went through and checked all connections to make sure they were moving freely or tight as they should be. I re-binded it as well (a few times over the course of test flying)....still no change. Had the whole 2 car garage for room, but as soon as I got it up about 6 feet (a couple of meters) or so, it starts revolving in that counter-clockwise circle. Again, adjusting trim made no change. Starts spiraling pretty fast sometimes too.
Toilet Bowl Effect indeed.
As it is, it is impossible to fly indoors, (which is where I bought it to fly). It's a calm evening, took it outdoors but that wasn't much fun, watching it spiral around.
I don't know, I must say I'm pretty disappointed with it. tried calling XHeli.com customer service but it was busy all day. (1 phone)?
If anybody has any other suggestions I'd be happy to try them out, but as this V911 stands now, maybe its trying to tell me where it belongs....

Have you checked the main shaft for cracks or splits?

[Mally99]

As Atom.. suggested.. sounds like a tail motor problem , especially the fast ccw spiraling .

[FoeDog]

Tail shaft and rotor shaft look fine. Tail motor appears to be glued on to its housing; I cant get it to slide in or out, or pop it up.
here's some pics, don't know if they'll help.



Everything looks normal to me. I keep hoping one of these suggestions will work.

[Atomnguyen]

I'm no pro, but it sounds exactly like the issue I was having. Weak tail motor. If you hold the landing skids and throttle up is the tail motor turning and does it sound strong. Try rudder left and right and see if sound changes. Or just try replacing tail motor. My issue was the back of the tail motor where the wires enter, the back part came off the housing and cause the tail motor to not be as strong. Try see if you can pry the round back off the motor housing a hair and see if it flies okay. If I pushed mine all way in it would spiral counterclockwise just like yours. Hope this helps.