Help with Futaba T8J

[tech514]

I have successfully swapped my stock TX & RX with pt his Futaba T8J. Thanks to DJIguys on YouTube and their instructional videos to do this upgrade.

Can anyone give me a step by step on how to now program in negative exponential on the control sticks as well as set a throttle curve to "calm down" all stick inputs as they are far too sensitive. I want my control characteristics on the Futaba to
Match as closely as possible the very smooth inputs of the Phantom stock TX.

I have seen a video on you tube where the guy states that -45% exponential needs to be programmed into airlerons/elevator and rudder controls, but no mention of the setting to smooth out the throttle response.

Any detailed help appreciated on how to set the Expo and throttle curve., thanks!

 

[Nwales]

Check YouTube for ! ThatHPI Guy ,as he does a talk through on basic set up .

 

[Gizmo3000]

It's pretty easy to test out the D/R Expo curves. the "flatter" more horizontal they are in the middle, the less sensitive they will be.
and the less steep on the outside the less travel the servo will go.
you can check the Servo settings in the Futaba menu to see how things are interacting.

I can upload a screen grab of what mine look like later this evening when I'm home from work.

There's another section in the Futaba menu appropriately named "Throttle Curve" to adjust the throttle curve.
i tried messing with it a bit once, but found it not too ideal, with my Phantom at least, it still had trouble maintaining altitude (tho imagine it would work better on my F450).

*important to put all these settings on a switch, or you might be unable to arm/disarm the motors, as the sticks won't go to their full throw position for doing so.

 

[tech514]

Thanks, that would be very helpful and much appreciated if you could post your screen shots of your Expo and throttle curve settings

 

[Gizmo3000]

So here's what I set all my D/R Expos to - ONLY when I switch my switch D down. (otherwise I'm unable to start my motors!)

Using this curve, applied to chan 1, 2, and 4, (I did it for each one), the travel is limited to 75% in every direction, and the 65% curve in the middle means that it's even less sensitive in the center.

Im actually thinking of changing my yaw (chan 4 I believe) to 50% ont he D/R, as it seems to still move way fast if I push the stick left or right.

*again, be sure to only make these settings when you have your switch in the desired "on" position so that they'll only be enabled when you hit the switch.

 

[tech514]

Thanks GIzmo- I just saw your post and actually flight earlier tested today with only -45% EXP for Chan 1, 2, & 4 set on switch A. I honestly didn't see any appreciable difference, maybe because I also need to set the D/R's like you did. Eeven with thr switch off I was able to control well, I just hate the lack of spring center on the throttle stick like I had on my stock Phantom TX.

I'm actually much more confident with the Futaba's range and ability to ignore interference, thats why I bought it.

I'll try your D/R settings and dial up my EXP to your levels and let you know how it goes. Many thanks!

 

[Gizmo3000]

Thanks GIzmo- I just saw your post and actually flight earlier tested today with only -45% EXP for Chan 1, 2, & 4 set on switch A. I honestly didn't see any appreciable difference, maybe because I also need to set the D/R's like you did. Eeven with thr switch off I was able to control well, I just hate the lack of spring center on the throttle stick like I had on my stock Phantom TX.

I'm actually much more confident with the Futaba's range and ability to ignore interference, thats why I bought it.

I'll try your D/R settings and dial up my EXP to your levels and let you know how it goes. Many thanks!

Cool man, yah, if you don't adjust the D/R, you might not notice as much a difference, just a bit less sensitivity in the middle (and then it increases on the outside!) but combining them with the lower D/R you're sure to notice a difference.

just gotta try out different settings and see what feels right for you.

I can't recall if it was you whos posted to the other Futabaa threads about it, but if you contact Futaba, they'll send you out a kit to make your throttle center sprung . at little or no cost.

But I keep my throttle normal, as my older Phantom Tx came that way as well.

 

[Gizmo3000]

Just took my Phantom out and changed my D/R down to 55%,.. think it made a huge difference, especially with Yaw, think it'll be super smooth for filming now.