Hi to all,

Yesterday evening, In my flight, some small crashes (no physical damages) and then I tried to take off again.

The heli rotates along with the fuselage and also it does not take off. I was trying all my possible ways but I could not.

Can anyone suggest me how to fix this issue? Please check the video below.

Try adjusting the "GAIN" and "PROPORTIONAL" controls on the 4-in-1 unit on your heli. Start with the "GAIN" one.

how to do this anwar?

There is a 4-in-1 controller unit on these Eky helis (like Robbins, Lama etc).  It is a white rectangular box, and you will see two small "pots" marked "Gain" and "Proportional" which can be rotated with a small flat screw driver.

You can see them in the link below (the two holes with a while line/cut). Insert a small screw driver, and turn the "Gain" one very lightly (something like 5 degrees each time), and test fly it.  If it got worse, turn in the opposite direction. Do it step by step. The final tuning is done using the PROPORTIONAL one.

http://www.rc711.com/shop/product_info.php?products_id=53

Sriharishine,
Forget about taking off. First try to get the proper tail control. I am not sure about this heli, but i think that maybe the gyro is reversed ? Or tail blades put opposite or maybe belt put the otherway.

Not sure this was of help, but i couldnt resist posting.

BTW good to see you trying to fly something !

I have tried changing the gain first, no change, it was as it is before.... And tried with proportional too. .... No change in the condition.... Still it is rotating with the fuse and not taking off

Then the gyro must have gotten reversed. How bad was the crash and what all did you have to fix / change ?

maybe you put the servo the other way ? I thought i could do this and potentially reverse the setting. maybe that was the case here ?

More than the servos, may be one of the motors was connected in reverse after the crash ?

Note that on most of these helis, the "gyro" function is done by the coax blades, and the servos are only for the swash.  That is why I was asking if any motor connection came loose in the crash.

Quote from: anwar on February 21, 2010, 11:12:02 AM
More than the servos, may be one of the motors was connected in reverse after the crash ?

Note that on most of these helis, the "gyro" function is done by the coax blades, and the servos are only for the swash.  That is why I was asking if any motor connection came loose in the crash.

The crash is not big one, I have not disconnected or connected anything, SO there wont be any chance for reverse, but to confirm, the switched in the radio (Rud, Thrtl, Ail and Ele) all are in the normal mode (not reversed mode).

And also the fuselage vibrates(like shivering) when I increase the speed.

can you also tell me the initial settings that would be right to fly it?

I have tried the Gain and Proportionals which does not reacted.

Quote from: gauravag on February 21, 2010, 10:55:06 AM
maybe you put the servo the other way ? I thought i could do this and potentially reverse the setting. maybe that was the case here ?

Please tell me how to reverse the settings, I will do it...

Thanks

The solution lies somewhere between [1] adjustments to the Gyro/Proportional pots, [2] making sure the motors are not reversed, and [3] adjusting the "rudder trim" slider on your transmitter.

You should be able to find the stability using one or a combination of above factors.  Remember that a small adjustment goes a long way while doing [1] above.

And if none of these helped, then the 4-in-1 unit may have gone bad   They are sometimes known to go bad if it tried to move the blades but the blades could not move (due to crash or being pinned to the ground etc).

Here are two related threads.

http://helifreak.com/showthread.php?t=111535

http://www.helifreak.com/showthread.php?t=140621&highlight=proportion+gain+adjustment

Yet another reason that someone pointed out is when the screws that lock the gearwheels to the shafts have gone loose. Please check those also.

Srihari,

Please ask the person from whom you got this heli may be he encountered  such problem earliar and might be able to help you

Rest all possible things have been covered in the above posts just make sure that the trims on the Transmitter are centered and the battery is fully charged

Hellyflyer

Hi Amit,

Thank you amit, I will contact him for this issue, In  the meantime, I am also searching for a person who fly this model and so he/she could recognize the problem and come up with the solution.

I fly a similar coaxial model Esky lama v4. I had similar issue twice and for once the culprit was the servo linkage that guides the tilt angle of the lower blade was broken (in short the swash does not move up or down). Second time it was that the the 4-in-1 mixer control was bad.

I also have exactly the same problem with my small palm sized model art infra red heli. I thought the batteries have gone weak. But even after changing the batteries, same problem.

Earlier I had faced a similar problem, but heli used to take off ateast. It used to get sorted by changing the trim setting on the TX. It was a very fine setting though. However recently, the setting does not have any effect at all. the heli does not even take off.. 

maybe another 1,000 bucks for a new one. 

So there is no solution for this issue???

Anyone there who can fix this issue for us???

Well there sure is some solution... but first we need to identify the cause of the issue. Is it possible to post close up pictures of the heli with the canopy removed? Given that it is a esky heli all parts can be purchased and replaced if the faulty part is identified. The issue could be as simple as one of the servo wire is loose. Both the motors seems fine as both blades rotate. Given that you have not made any changes I can only suspect the servos and the servo linkages

Does the heli stop spinning or the rotation slow down when u apply yaw in the opposite direction of rotation?

yes, We are nearing to the issue, If I apply yaw in one direction then the rotation speed is increased and when I apply the opposite yaw, The speed is decreased but rotates in the same direction...

How can I confirm that the Wire to servo is loose, Since the both servo works as per instruction of the tx?

Ok so looks like either some linkage contorlling the swash is broken or the 4-in-1 controller is not functioning. Does it blink a red light on the 4-in-1 controller or is it solid green. Did u happen to change blades. It may sound stupid to ask as you have said u have not changed anything. But inter changing the blades A and B will cause the heli to spin and not fly ... so just confirming... Pls try to post some close up pictures if possible