Definitely got it in heading hold mode ?

Or gyro compensating the the wrong way

Is it a 3Gx fbl controller? Sounds like not in hh mode. There is 2 lights on the unit. From memory when I hh mode it is green and red in rate mode.
How much tail gain have you got set?

Yes it is the 3gx fbl how do I find out what mode it is in and how do I change it also the same question re the tail gain.

they're two leds on top. If one is green (status), you've got heading hold (correct). If red, it's rate mode.

It's controlled via the gain channel from your TX. If gain = 1 to 100, it's HH. 0 to -100, it's rate mode.

If your using the 3GX unit and have it mounted upside down, then like Gixerman said, you need to reverse the gyro compensating setting.

Hi thanks I managed to sus out that the reason I couldnt switch it was when it is in HH mode (green led) the gain has to be >50 - 100 otherwise it wont switch found someone on another site with the same problem.

So I tried different gain settings and it doesnt make any difference it just wants to go round in circles.

Unfortunatly as I tried to take off it crashed and now my landing gear is in several parts as well.

So anyone got any other ideas.

Yup did that during the setup.

Are you sure the compensation is correct. It does sound like correction in the wrong direction. Don't know if you've seen this ...

Align 3Gx Tail Setup - YouTube
T

T-rex 250 DFC tail spinning

Had the same problem myself and switching the orientation always fixed it for me.

I have gotten into the habit of spinning up after a rebuild on a slippery surface (kitchen Lino in the case of the 250) so the tail works long before it takes off so I can catch this problem.

I have run that full setup again and I have managed to make some old belt cp skids fit and fixed the broken link in the head, so I will try again tomorrow and report back.

With the top tail blade pointing upwards fold it forward so its parallel to the boom. Looking from the back forward if you move the rudder stick to the left the tail blade should point to the left. Stick right tail blade right. That the easiest way I know to check the direction is right. First check it is driving with the stick the right way. Then pick the heli up rotate it left and the tail blade should point right to compensate. and move it right tail blade should point left.

When in HH mode if you boot up the heli the tail should sit roughly in the center (not so important) then spin the heli 90 deg left. The tail should point hard right and sit there. The reason it should stay there is the heli (nose) is gone left the tail has corrected to the right but the heli hasn't responded so the tail stay hard right. If you rotate the heli back to the starting point the tail should recover back to its starting point. Not sure if that makes sense to you but have a play and it might. Had me totally stuffed the first time I did it.

If you can plug in to the PC and go to setting display page with the heli booted up you can monitor what is going on. Check the rudder reverse there and also check the gain. You should be able to change on the TX and watch it change on the screen.

only done one 3GX setup in the last 6 months so a bit rusty but have just built a Copterx 250 and put my 3GX back on. Have been having tail setup problems but was due to rubbish TX. Have now got a new RX and setup on my JR XG7. Havernt had a chance to fly it as need some parts to finish and away for the weekend.

Let us know if you get sorted.

OK so here it is I have finally got it to fly, thanks to everyone for all their help and please excuse the skids they are a bodge as I broke the other ones.

Good stuff. What was the problem in the end then? (tail compensation direction?).

Hope you don't mind, but couple of bits of advice from watching your vid ...
* Find somewhere with a lot of space! Youtube is littered with crash vids of people trying to learn the confines of a back yard ...
* Be careful with take off and landing pads. Here's an example why ..