Has anyone tried or can tell me how to convert hobbyking 2.4ghz 4ch radio from mode 1 to mode 2? Is it possible to change the self centering gimbal from left to right?

I am asking this because i was offered a good deal for a Mode 1 radio. But i want mode 2 because i read its easier for heli flying and i also read its difficult to change from one mode to another. Another reason being , in the poll (pinch/thumb mode1/mode2) majority use mode 2, most of the flyiers whom i know also use mode 2. So if i use mode one getting help in trimming will be difficult (which i will need by virtue of being a newbie).

I dont have hobbyking radio but i have converted futaba skysport4 from mode 2 to mode 1. I have also converted art tech simulator from mode 2 to mode 1 and the process was same and I think it will be same for all tx.(I dont know about programmable one)
You will need to open the case of tx and then manually change the spring.

This is non programable. This is how it is inside :

Link to high res image of hk6ch but 4ch should be similar i guess : http://farshidjh.files.wordpress.com/2010/03/hobby-king-6ch-transmitter-inside-pcb.jpg

The pic u have uploaded seems to be of mode 2.
In case of your radio (mode1) things will be like in pic I have uploaded here.

Be careful with electric circuits while doing this.

Here is the video of doing this.

Part 2 of video is here is here

The problem is in the pic of the 4ch i posted (not the link) i dont see the wires from the pot to the main board. do you see anything? (stupid question, but just incase my eyes are playing tricks )  It it possible that the pots ate directly connected to RF module? Not possible right? It has to be connected to the main board right???

The circles i have made in pic attached are the circuit connections to the pot. Wires going from these circuits are going to main board of you see carefully.

Ah i see. I was looking in the wrong place. So now i can change the center positioning spring and throttle ratchet. Next - do you know it the wires from the pots are soldered to or plugged to the main board? All i need to do is swap these right?

People have commented about converting from mode 1 to mode 2 on the HK forums, that it is possible.

Remember the trim switches also, during the surgery !

According to my understanding it is not possible to connect pots directly to rf module as pots must give their output to encoder IC as signals must be encoded before sending them.

http://farshidjh.files.wordpress.com/2010/03/top-side-of-the-hobby-king-6ch-transmitter-controller-board.jpg

it shows plugs so i can swap them right?

I think that should work.

This is what i understand :
1. Change spring and ratchet to make the right auto centre and left non centre.
2.I believe each of the channel pots have one red, one black and one diff colour wire : brown (ch 1) ,yellow (ch 4), orange (ch 3), blue (ch 2). So i need to change these accordingly.

Are the trims directly connected to pot? So no wire?

Attached pic is ok 6ch cos i dint find a 4ch pic. The board will be same right? Cos 4ch has servo rev switches and 6ch doesnt but the board shows provision for the switches.

To change modes (1 to 2 or 2 to 1), you need to only change the two sticks that move from bottom to top (not the ones that move side ways).  So the pots for that movement will be mounted HORIZONTALLY ! 

In the last picture, I see white connectors on the pot side.  So all it would take is to switch the connectors to the two pots mounted to handle up-down movement, along with the tension spring and ratchet. And if the trim tabs are mechanically connected to the pot, they should be fine.

Yeah i understand now. Thanks. Im do not know it the trim is connected to pot directly -just assumed because i dont see any wire for trim.

The Rf module in the 4ch and 6 ch radios look exactly the same. Main board also is the same. so is it possible to convert 4ch to 6ch??

The trick would be updating the firmware, it seems.

Hmmm... need to find out how.

Attached pics of the radio.
Changing the spring and ratchet seems easy.
Once i do this should i change pot connection???

Currently ch 3 is throttle and ch 2 is elevator.
So after the spring/ratchet switch can i connect elevator to ch 3 and throttle ie.ESC and BATTERY to channel 2 on the reciever??

If this is possible then i dont need to touch any pot.

Can the power/battery/esc combi be connected to any channel on the reciever?

In your picture, just interchange the pots you have marked with "POTS TO INTERCHANGE" with the right polarity, and that should be it !

Anything you do on the receiver will NOT change the mode of the radio, as MODE is defined by which stick does what (and NOT by what channel does what!).

Changing the pots will reverse the +ve and -ve terminal (cos the small board can be connected on one side), the point A and B which are on top in the pic will come down once i switch them. - this will cause channel reversal. My radio has servo reverse switch so toggling the switch will fix this right?

Isn't there a connector there, that you can switch around, instead of the whole board ?  It looked like there is a white connector there in one of the pics.

Yes, you can use channel reversal to handle that. 

Mixing will be a problem if using channels for diff purpose than intended

Plus 1 for reply 14, 20 and 22 of Mr Anwar. I have received the HK 2.4 Ghz 6 Channel Mode 2 today done full postmortem. So Trim is mechanical and as suggested by Mr Anwar do not change pots physically. but only interchange the connectors to the pot board at main board or at the pot board. along with interchange of change of loc of ratchet and springs

@anwar : yes there is a white plug like thing but the solder is very fine. I will try that first. The board on the POT is just a BOARD. Only used for routing the for lines to the plug - nothing else. The trims are mechanical and move the pot - so no problem there.

@sundaramvelar: Thanks for your inputs.