Art_P

I purchased the RTF helicopter this week and tried to execute some pre-hover exercises. Without lifting-off, one or more servos went haywire, and I shut it down. When reconnected, the 3-in-1 controller LED flashes between green and red. The servos work but are not centered, and the main and tail rotor motors do not operate. There are no instructions regarding the LED flashing, and I can find no viable technical support at Xheli or Esky. Can anyone offer any advice on what I should do?

aircrash

Well, Ihave no CT but from what Iknow out of the Big Lama is:

Led flashes between green and red -> 3in1 controller has not initialized properly. There is a fault or open throttle. Make sure the throttle stick is all way down before you connect the li-po. The same for the throttle trim (except if the manual says the opposite).
But there is maybe a fault.

Now the erratic behaviour of the servo. Most probably is faulty. If it is not then it could be the Rx or Tx, but I don`t think so. It is usual a servo failure or being bad, but rare for the other mentioned.
In any case you must replace it. Or if you don`t then it may cost you too much money on repairs. As if it makes any erratic behaviour during a flight then you`ll loose control and it will crash.
Most probably this makes the 3in1 not to initialize properly.

You can check if it is the bad servo that makes the 3in1 problem by disconnecting all the servos (make sure you mark them and write down how they are plugged) and removing the main blades (just for safety).
Then see if now the 3in1 can initialize properly. If it is like Big Lama`s then it will. But I can`t know if it won`t without installed servos, as it may differ to the operation.

Ohh, Ialmost forgot to mention you should also check about the reverse dip switches. Your throttle may be reversed so you have all way down the stick but it sends the opposite signal to the receiver. You must do any adjustments with main blades removed.

If you find no solution then speak with the shop and arrange to send it for checking.

Art_P

Thanks aircrash. After reading your reply, I checked the transmitter and found the idle up switch on. After correcting that, the 3-in-1 controller LED is green, and the motors work. The servos are still a problem. They work for a few minutes and then go crazy again. One is definately not functioning correctly. Would replacing all of them be the best next step? Or, is there a procedure for testing the other two?

aircrash

Well, if one servo is bad then it may make the other to act weird too. That`s about normal.
Start over the bad servo and then check.
A bad servo makes too much noise (normally no noise at all would be present), even with no stick input. Also moves by itself. Sometimes it gets hot too.
You could test the servo by using a servo tester.
Set it to automatic and it will make the servo move from one side to the other continously and check if the servo works with no glitches. And at the manual mode if it makes noise at a specific point.
Be sure you don`t test the servos while they are connected to the swashplate. Remove the ball linkages or else a failure may happen.

Art_P

Thanks again aircrash. You gave a pretty good description of the bad servo's actions. I guess I need to order a servo and a tester.

aircrash

You`re welcome.
Well, Iassumed you`ll go for a servo of the same model as replacement. But just in case I`ll tell you to go for a same model or else you`ll have problems.
As long as the other are new then it is OKto replace just one (or two) of them.
Be sure the swashplate is level after the servo change.
At least see where the original servo centers (have the servo tester to neautral mode and the servo will go to its center) and see if the new one centers about at the same point.
If not then the linkage rod will need an adjustment so the swashplate remains at the same position.

Art_P

I ordered two servos just in case. They are Esky replacements (digital). I don't understand your comment about seeing where it centers and adjusting the linkagerod since the arm position can be adjusted. I will find the servo center position with the tester and install the arm horizontal, so the linkage rod should fit without (much) adjustment.

As far as the horizontal swashplate, I experienced that the helicopter drifts left even with the swashplate tilted slightly right. I was operating with extreme right trim. In fact, it basically doesn't want to go right at all. Any thoughts on that?

aircrash

Each servo has a slightly different center point, most of the times.
The servo horn can be adjusted but in steps.
The step is too big for the slight difference of the center point and you can`t make the servo horn be at the same point that was in the previous servo.
But you can manage this slight difference through the adjustment of the linkage rod so the affected component, which is the swashplate, remains at the same point even if the servo horn point is different. A small difference makes a large effect and the heli will tilt quite a lot.

Hmm, maybe you should get a swashplate leveler (a tool).
Of course you must first check with the new servo(s).
Some other use a zip tie to check if the swashplate is level. http://www.youtube.com/results?searc...42l0.3.2.1l6l0
Check the manual if it tells anything about.

Art_P

I like easy, and that certainly is. I'll do it.

av8tir

Is it possible to remove the Fuselage without cutting it...I could not find anything online that shows how to disassamble this helicopter.

Art_P

I had to remove the tail rotor motor, which required removing the wire connections and soldering them back.

Art