RC helicopter spinning out of control problem

[Admin]

A friend recently gave me his Blade CX RC helicopter. I spent ~$30 getting a new battery so I'm vested and need to fix another problem I'm having.


The problem wasn't happening at first until a light collision with a wall. Now even when putting the trims on max, the helicopter still spins on itself. I think its a blade balance issue:
The gearing for the top rotor rotates smoothly, but the gearing for the bottom rotor vibrates a lot! I don't see any damage to the gears, but it looks/feels like its meshing too tight or something . . . I'd normally just replace the gears, but the gears there already look fine . . .

Anyone with experience can help? Im a noob for RC heli's . . .

[paulstreats]

Is maybe the centre axle bent slightly.

Ive got an rc heli a bit like that and there is 1 axle inside the other kind of. The axle or whatever for the top blades goes through the axle for the bottom blades, I always thought that if something was catching around that point or even if it just needed oiling a bit then the whole thing would start spinning.

(taking off is the difficult part, once i get mine stable in the air its fine it just spazzes out a bit at take off )

[Admin]

ok I'm almost 100% positive the problem is because the gear meshing is too tight.

browsing around I found this post:
http://www.rcuniverse.com/forum/fb.asp?m=4587495

I tried several times and its still not working . . . one of the motor screws is jammed under a gear making it really hard to reach . . . I also added servo grease to the gears but that didn't help.

I think I'm gonna put it down and give it a rest for a bit . . .

[TrickyNekro]

I think it's a blades that did go unbalanced...
Try to take apart the blades and let the shaft rotate...
If it's no vibration try replacing the blades it's the most common thing breaking cause of it's high torque...
And can cause vibrations easily....

I don't really thing it's the plate that has a problem... can far as I know for these inexpensive helis
the blades aren't fixed on the shaft in order to produce max torque at any RPM...

I insist it's the blades that are all messed up...
Try replacing them...



Cheers,
Lefteris

[Admin]

Tricky . . . I have no idea what you just said lol . . .

Anyway, it appears that the paper in the gear method with servo grease worked
The bottom gearing still feels much tighter than the top gearing, but it flew entirely balanced.

I'll fly it for a few hours and when I get decent at it, I'll post video.

[TrickyNekro]

Well, I just see what I said was quit irrelevant...lol 

The strange thing is that it has also happened to me...

Some guy gave his mini coaxial to me to fix it...
It seemed the the two axis have just stuck... and it was the gears they were like glued together...

Anyways, It seems in your occasion that a rotor get less torque than the other as noticed and fixed...

Try getting the gears apart "oil" them and get the heli back in one piece in order to avoid the paper...
To tell you the truth a good photo can help me much more than just talking... to get a conclusion...


Anyways, flying an RC heli or plane(which I never tried) it get you another feeling of space...

Happy flying hours,
Lefteris