I am using Spektrum Dx6i radio.
My throttle stick is having problem.
All the other sticks are working fine.
when my throttle stick is at full position, throttle is 100%
but throttle doesn't come to 0% even if the stick is at lowest point.......but instead the throttle fluctuates between 50% to 80%!!!!
Please help me out...........

Please adjust ESC.
Check ESC Manual for Maximum-Minimum Adjustment.Its the Throttle position after beep code of cell that programs the ESC immediately after connecting battery to Receiver (infact ESC too.)

this has nothing to do with ESC.......actually i was practicing on simulator during which i acknowledged the problem.
Also i can monitor this problem on radio itself on frequency bar....

This ESC problemed me while throttle reversed.
However, do you have the manual of the radio? Check youtube for setting various parameter and mixing. Surely you will get it.

or lots of similar available.
and Manual might help.
http://www.bladehelis.com/ProdInfo/Files/SPM6600-Manual_DX6i.pdf

I think it is potentiometer failure..............
what should i do???
shud i replace it??

When does it come to zero throttle. Does it come to zero throttle at all?.

Some time the hot glue holding the pot body to tx body and knob shaft to the joystick comes loose and creates such a problem.

But if it is coming back to zero throttle after you switching off and switching on in stuck throttle condition, then It may not be POT problem.

Anyhow you should open tx and check for looseness of POT and try replacing it if you can and if it is available.

Also change mode and see it is the problem with same joystick.

I think the orignal problem is being seen on the simulator so I think that either your idle up switch is flicked on or the throttle curve is set for idle up setting which is like a V shape for negetive pitch which increases the throttle from 50% to 0%

I don't think there is any problem with the Pot

I think you should post a video showing what is happening, show the in the video the positions of all switches and also show the display screen showing the throttle curve settings

Hellyflyer

Solved the problem, thxs anyway...........
i googled for the problem and got this link
http://www.rcgroups.com/forums/showthread.php?t=954175
it explained the problem of potentiometer............
i followed the steps mentioned and volla, its working fine!!!!!!!

Great, good to hear that

If the problem is in POT, which is the heart, then Dx6i must not be used as it is not so cheap.

Hmm... wonder how many face these problems. I have a DX6i and have not noticed this issue till date. But I understand that POT being a mechanical way of varrying the resistor value, I wonder if this is related to usage.

Yes, definitely the usage.
The life of single Tx of Tarek will be 10 times minimum for usage.

The thickness of carbon resistive film, it's brittleness or softness with age, contact plate resistance, and oxidation rate of metal surface (Also depends on the cream which serves 1. Lubricate 2. protect surface oxidation.) determines the quality. This POT with spring and hinge assembly determine, how long it will be reliable.

With this thread, I am sharing an experience.
In our radio, in my childhood, several times, the volume control got damaged and my father took that to technician and he replaces that all the time.
One day I just checked for curiocity and found that :
1. The volume was increasing and decreasing.
2. While the V/C knob is not rotating, it was working nice.
3. During changing the volume, some bursting noise comes.
4. From center point of V/C, no ground fixed resistance.
5. POT Contact rubbing (circular metal of moving body to fixed contact of centran pin) mark is there.

Now I just take very thin (probably 40SWG) wire and making spring on an paper clip.
Soldered one end to moving contact and another to central pin like flexible coupling.

The problem vanishes and never occurred till date. But the point to mention is that initially it  was a low cost (MIC) V/C but later it was replaced several times (not less than 10 times as I remember) with firstly Philips and later MIC POTs. and lastly I do the trick in cheap MIC POT.

So, any weakness will become bottleneck of the complete system.
And if the problem is the manufacturing problem, the brand items should be checked whatever costlier the brand be and a cheap brand Radio can beat it.

After all costlier brand and brand name comes from reputation and past history.

And in this case,

Thats exactly my point. Is the Potentiometer problem an issue with Spektrum in general (meaning low quality control) of does this seem to be a one off case?