Hi,

My Friend have Double Hourse 9104 3-Channel Fix Pitch Heli, bigger then 250 size heli

http://www.rc-fever.com/double-horse-9104-3ch-metal-helicopter-w-builtin-gyro-blue-p-13029.html


By connecting opposit battry connection, he bust his heli board (image attached, 1 & 2)

Then he ask me for repair, I found few parts are not good condition, So I bought them (tail boom with motor, Mainshaft ) including main board from rc-fever.com

I have installed them, but now when I am giving throtal, heli tail is moving very rapidly from right to left (spinning)
then I hold tail balancer and try to give throtal initially heli try to spin but after 1-2 sec it reduce motor speed and it dont spin,

What is issue, is Gyro is not initiating ?? or motor speed is variable ?

I only found IC sticker is different from Old board and new board....image 1 & 3

Can anyone suggest......

These electric chips (boards) are very sensitive and complex in terms of design made by chinese. These boards internally contains Gyro, ESC, Receiver and battery charging socket every thing. Two sets of black and red wires will come out of the battery. One set will go to board and the other set will go to charger for charging purpose. If you reverse the battery connection little smoke will come from the chip and it will burn out. I too faced this situation for one of my chinese helicopter like urs.

Coming to ur problem, "when u give throttle heli spins for 1-2 seconds and it reduces motor speed and it dont spin". First Check ur battery, if it is getting charged properly or not. After charging fully, test the battery. Try to test with some other battery of same voltage and same weight.

Thanks buddy,

"when u give throttle heli spins for 1-2 seconds and it reduces motor speed and it dont spin".
To stop spinning I have to hold it stabilizer with hand, initiall heli try to spin, but it cant because I am holding it with its tail stabilizer.

I have charged battry full and then checked on volt meter it shows 7.4, then I try to flew and after that I checked volt again and it was 7.1

FYI..I have changed its Main board, charging option is not through Board.

anyone plzz help

normally these boards have a potentio meter a.k.a pots on the board which are used to control the speed of the counter rotating motors. adjust that and see if it stops rotating.


Hellyflyer

hello hellyflyer,

Yes there is a pots, in right down corner, in pic-3, but my problem is initially heli try to rotate
If it dont stop it, then gyro confused (i think) and heli rotate continously.

but If I start it by holding tail stablizer, then heli try first 1-2 sec then reduce its tail roter speed automatically

Any suggestion plzz

a similar problem is discussed here. check it out.

http://www.rcgroups.com/forums/showthread.php?t=1587926

Quote from: gbisht on February 10, 2012, 10:24:00 PM
hello hellyflyer,

Yes there is a pots, in right down corner, in pic-3, but my problem is initially heli try to rotate
If it dont stop it, then gyro confused (i think) and heli rotate continously.

but If I start it by holding tail stablizer, then heli try first 1-2 sec then reduce its tail roter speed automatically

Any suggestion plzz

What you have mentioned is correct as the gyro corrrects the spin after some time and keeps the heli stable but you need to start by moving the dial (in any one direction, but make sure to mark the orignal position) and observe the rotation of the heli if it increases then move the dial in the opposite direction and so on till the time does not spin VIGEROUSLY at 50% throttle, a little spin which can be corrected with trim is normal.

Hello Vishal,

I have read that blog, and test the same, my I am confused now,

I removed Main rotor, and only connect tail motor, I start give throtal, initially it start spin fast but I am holding it, so in 1sec  it drop's its speed and blade start rotate at normal speed, (Heli is facing me) now I am moving heli left so it increase tail motor speed, if I am moving right, its not doing anything,
when I am increasing throtal speed, tail motor is not increasing its speed but when I am moving heli body it responding aggrassively.

Trim adjustment will be last option, because hot glue is already on it, you can see on pic-3

imp. thing I changes it Factory Nihm battry with my LiPo battry, now tail blade is moving on constant speed early variation was their....
Thanks everybuddy.......

hi
ur nimh battery seems to have lost its capacity. try checking the voltage when only tail is running. u'll definitely need to adjust the trim  for it to stop spinning. also since it has a fixed pitch tail rotor just check if its turning in the right direction.

as this is a fixed pitch tail motor driven heli, the tail motor has to work a lot to keep the heli balanced. And being fixed pitch tail rotor it blows out air in only one direction (check for correct direction on youtube videos) and is dependent on the main blade speed and torque to balance the other side.

So the tail motor should have variable speed which should increase and decrease with throttle stick to keep the heli stable (not spining)  and it's ok if the rotor only turns if you give left rudder and does nothing when you give right rudder as that's how it should be.

pod trim is not the last but the only option which can fix this issue.

Hope this helps and you next post be that it's all fixed 

Hellyflyer

Thanks Hellyflyer/Vishal & All,

Tomorrow I will take it to ground and try to fly it ....and keep you update