No linear servo travel!!!

[mceachern12000]

Question...I have recently purchased a Futaba 7C 2.4GHz radio from Tower Hobbies for setup with a Trex 450SA/SE (hybrid)...I have been following your web site for several months now and have been quite impressed!!! The problem I am have is that when I go to setup the head (YES I have been following Finless's video closely...Thanks Finless) I am getting significantly less movement from the cyclic servos from center stick (throttle/cyclic) to full stick than from center stick to full negative. After several attempts the most pitch I can aquire at full positive is 9 degrees...and at full negative always excess of 12 degrees. I have taken the servos out of the aircraft and tested the cyclic response again. With the radio reset and parameters at HR3, throttle/pitch curves 0,25,50,75,100, ATV's at 100 percent in both directions, subtrims at 0, all trim tabs centered, and the swash menu at +50 in aileron, elevator, and pitch...I still get significantly less servo travel from center cyclic stick to full stick than from center stick to full negative. I would like to know if this is common with the futaba 7C or am I not understanding something. I would appreciate any helpful advise.
Thank you.

[DavidH]

Need to move the swash plate mechanically a couple of degs towards the positive pitch direction. You can do this by adjusting the links to the swash plate from the servos. Then mechanically reset 0 pitch at mid stick again.
At +9 and -12 that is 21 degs pitch range. So at midstick ( 50%) you should have - 1.5 degs at mid stick. With +10 to -10 you would have 0 at midstick.

David

[mceachern12000]

Thanks for the helpful reply David, I will give that a try.

But I would still like to know if it is common for the 7C to have nonlinear servo travel (i.e. less travel from center to positive than from center to negative?). Even when the Pitch curve is set linear?

Thanks.

Patrick

[fritzthecat]

Did you INH the Hover Trim knob? If not, then this can slew the center of the pitch curve.

Fritz

[mceachern12000]

No, I did not know about that... Thanks:). I'll give it a try. Do you mean to inhibit the VR knob or set it to center...I have not even noticed where it is set.

Thanks for the great advice Fritz.

Patrick

[BarracudaHockey]

Thats probably whats going on.

There's two solutions, the first is, inhibit the damn things. HOV-THR and HOV-PIT

The second, is to do your setup in Idle up 1 or 2 where they have no effect.

They are useless unless you hover at 1/2 stick which most 3d guys dont, and are a menace during setup as you have found.

[driftless]

I had the same problem when moving from my 6EX to the 2.4 7c...I inhibited the knob and all is well again. :)