I'm setting up a 35% plane working for the first time with the Hitec programmer and I've seen DOD videos demo the usage of the programmer quite a few times.

I still have one thing that I'm not sure about. In one video he was talking about setting up the servo and linkages mechanically to acheive exact same movement distand of the servo arms to both directions and the movement of the control surface both up and down the same distance. Achieving it by ajusting the linkages length and as far as I understand this is done mechanically (moving it by hand). and only then setting up electronically with the programmer, but I didn't understand how come when we set up the end points we are not getting the exact same values (for up and down). for example -130L and +130 right and if those values are different from each other how come liniarity is not harmed (one direction faster than the other) ? I would think that it wouldn't damage anything as long as the center is exactly between the two end points but in case of two different values for left and right the center is already set therefore the travel of the servo arm is no longer the same distance to both directions and that what confuse me.

Another question I had is about the dead band, do you use this function when you gang rudder servos ? do you use this function on a multiple servos control surfaces as ailerons?

Thanks for your help

Ideally the mechanical setup provides equal travel volume in both directions. This is achieved primarily by adjusting the control link so that the servo arm angle is centered in the travel arc at surface neutral.

Unless you start at a “0” neutral value the values will not be proportionate to achieve equal travel arcs. Even with a “0” reference point you maybe off slightly due to electromechanical tolerances of the servo in play. If your servo arm needs to be programmed for -10 to match the required servo angle for equal travel arcs you have an offset in play. So your numbers will be skewed in the direction and number of the offset.

-10 is the zero reference point
-10 + 130 = -140L
-10 + 120 = 130R

In either case you value is 130.

I’d recommend programming the dead-band to the lowest value as long as you pay careful attention to linkage binding and current draw at neutral and extreme travel.

H9 and others offer inline current and voltage meters that plug into the servo connectors which are invaluable IMO for determining a proper setup.

Hi Michael


Ideally the mechanical setup provides equal travel volume in both directions. This is achieved primarily by adjusting the control link so that the servo arm angle is centered in the travel arc at surface neutral.

Unless you start at a “0” neutral value the values will not be proportionate to achieve equal travel arcs. Even with a “0” reference point you maybe off slightly due to electromechanical tolerances of the servo in play. If your servo arm needs to be programmed for -10 to match the required servo angle for equal travel arcs you have an offset in play. So your numbers will be skewed in the direction and number of the offset.



-10 is the zero reference point

-10 + 130 = -140L

-10 + 120 = 130R



So this is what I don’t understand. If the values are -80 and +130 it will have a linearity or not? You can see in the DOD vids that the values for up and down are different and not the same values but he still explains that it will have perfect linearity which I don’t understand how. Maybe because you program the servo and not through the tx the servo (after you done) works the entire range is same speed ….



In either case you value is 130.

How come? One is 140 and one is 130



I’d recommend programming the dead-band to the lowest value as long as you pay careful attention to linkage binding and current draw at neutral and extreme travel.

What is the lowest?



H9 and others offer inline current and voltage meters that plug into the servo connectors which are invaluable IMO for determining a proper setup.

I think I have it. Is that the “Digital Variable Load Voltmeter”?
Thanks for your help

Where did you get -80?


Subtract -10 from 140 and you get 130... Count the integers. 130 and 140 are the set points not the number of steps.

1:1

No the device you mention is a loaded ESV, not a voltage and current measuring device.

I see
So the programming of the servos should be values that will set the center in between the two end points and only then we will have linearity?

On the DOD vids it looks like it is not in between the two (one value is too high than the other one in relation to the center reference)


Another question I had is:
All the servos on a multiple servos surface must travel the same distance left and right, that we know
But all the servos should travel the same distance as well? For example all should travel 55 degrees left and right or each servo will have its own even values?


I’m also having a problem with some Hitec servos that don’t center
Even after rest and set them up again they don’t center. Every time I move the stick and release it the center is different (new JR 9X).
The pulse read shows a different value every time as well.

Any advice about that?

Thanks you very much for your kind help