Rc helicopter rotating on itself

[nokvarze]

sup guys? I have some problem with my 3 channels RC helicopter and I was wondering if you could help me.  So here it is:  Recently Ive bought a 3 channels RC helicopter and I was super beginner at it.
I didn't know what to do and on my first flight I crashed into a wall.
I'm not entirely sure where it broke, but I think its the tail, maybe somewhere else.
So I sent it to repair(they charged me about 8 dollars) and got it back.
Now I'm having a problems with it. The Heli is always spinning on itself.
That's sucks because its an indoor Helli and really hard to control as it is.
I was trying to move the trims but nothing really helps, it still flies bad spinning on itself and I cant control it.
If someone could help me fixing the rotating problem, it will be super great.
Thanks in advance Nokvarze.

[Cristi_Neagu]

Hello.

A spinning helicopter means a damaged tail rotor. It could be damaged even if it's spinning. It might be that the tail rotor isn't responding to commands anymore.

You could try posting a link or photo so we know what type of helicopter you are using.
 

[nokvarze]

I dont think  its the tail rotor because I have  sent it to repaire and they fixed the broken parts.
What else can it be?

[SmAsH]

Well, the tail rotor is the primary means that the helicopter uses to keep itself from spinning...
How are you sure it is not the tail rotor?

[nokvarze]

Well, I think its not the tail rotor, but im not entirely sure.
I said that its not the problem because the  heli has been fixed after I crashed into a wall.
Anyway I will try to replace it. Is it a big deal to do that?

[Soeren]

Hi,

Send it back to those who repaired it and ask them to fix it good this time AND test it afterwards, obviously, they didn't do that the first time around.

[nokvarze]

I guess you are right because it shuldnt be spinning like hell normally.
But even, I dont see any injuries or skretches or damage on the heli, so I cant understand where the problem is.
Should I  disassemble it and see whats going on inside?

[Cristi_Neagu]

You'd be better of taking it to be serviced. If you open it, you might do more damage. If they tell you that it's hopeless, and they can't do anything about it, then you can open it. But until then, let them repair the damage, it's their job. Also, make sure you rub it in how shotty their previous repair job has been.

Best of luck.

[amando96]

rc helicopters require A LOT of trimming, your remote should have some adjustment knobs, move them, until it's good to fly, i recommend grabbing it by the landing gear with your hand, so it won't fly off and break.

good luck
or maybe one of the servos is on backwards, if not, the trimming should do, even dirt cheap choppers have those adjustments.

[nokvarze]

I understand what you  say but I already tried to adjust the trims and it makes no difrrence.
The heli  still keeps moving where  he wants and spinning like hell..
I better try to find where its broke.

[Comrade117]

It must be the tail rotor, synchronizing between tail rotor and main rotor, or one motor is spinning in opposite way.

Hi,

Send it back to those who repaired it and ask them to fix it good this time AND test it afterwards, obviously, they didn't do that the first time around.

Yes, that is the best way. If you are a new to robotics, you can do even more damage opening it. Oh, and remind that guys that first time they did nothing useful, so they can not take more money from you.

[Razor Concepts]

It would really help if the OP mentioned if this was a toy or a hobby grade heli, as there is a huge difference in setting up between the two 

[nokvarze]

Its not a very serious heli. A regular 3 channel one. Anyway im taking it back to repair, focusing on the tail rotor.

[paulstreats]

It could be the shaft of the main rotor.

If the inner shaft is slightly bent it may be rubbing against the outer shaft causing your helicopter to spin in the direction of the main rotor (On take off most small heli's try to spin on takeoff because of this type of drag. they also try to spin in flight but the tail rotor and gyro should compensate for this. its up to the pilot to compensate. but if yours is slightly bent then this effect will always happen.)

As mentioned above, the tail rotor should compensate for spin once successfully in the air, so maybe your shaft is bent and the tail rotor cant compensate strongly enough, or the tail motor itself could be damaged.

[Razor Concepts]

Since this is a 3-channel toy, the tail rotor is actually horizontal and does not prevent rotation. There are two main coaxial motors that cancel each other out. Something like this:

[paulstreats]

So, you understand that the shaft for the upper rotor has to pass through the shaft of the lower rotor.

This creates torsion due to the friction of the 2 shafts rotating in opposite directions but with 1 passing through the other - leading to the helicopter spinning in mid air. In this case the 2 main rotors compensate for the effect.

If 1 of the shafts was damaged (ie slightly bent), then this effect would be greatly increased making it difficult for the rotors to compensate.

If the tail rotor were mounted horizontal like in the picture, then it is very unlikely that getting that repaired again will not solve this problem.

[Soeren]

Hi,

[...] then it is very unlikely that getting that repaired again will not solve this problem.

I guess you meant the opposite?

I don't think there's gyros in the cheap choppers, as they're simply cheaper than the gyro itself.

Perhaps I should open the one I bought some years ago (and never got around to actually get out of the box, Lithium battery is most likely dead by now) for aerial photography of our holiday cabin. I think I need a larger one, able to hover in a mild breeze and be able to carry a bit more weight, but this is a project on hold for an unspecified time.

[GWER57]

I had this same problem too!

It turns out that the main gear was loose so only one of the rotors was spinning with power!

All the repair people had to do was to tighten the set screw connecting the gear to the shaft.

Best of luck!