Radio/Servo Set Up – Step By Step Process

Here is my basic set-up procedure, regardless of plane or radio brand.


This
assumes a six channel computer radio controlling a full house plane that
has flaps and retractable landing gear. I will touch on what you can do if
you don't have flaps or landing gear later in the post. If you have more or
less channels, the steps will be the same but the options will be a little
different.

Hitec/Futaba Channel Assignments
JR, Airtronics and others may use different sequence – doesn't matter

• Aileron in 1 – If you have two servos, you use a Y cable
• Elevator in 2
• Throttle in 3
• Rudder in 4
• Landing gear in 5
• Flaps in 6 – If you have two servos, you use a Y cable

I usually power up the radio and select a new memory position. If I am
replacing an existing profile that I am no longer using, I reset all values
to stock settings of 0 or 100% as called for in each case.

This procedure assumes you have your servos mounted and the control
rods/cables attached to the surfaces and the servo arms off the servos.

Power up the plane. If this is an electric plane, I use a 4 cell receiver
pack battery rather than the motor battery attached to the BEC in the ESC as
I don't want the motor in play right now.

Check for servo direction. When you work the servo, will the servo move the
surfaces in the proper direction? If not, you use the servo reverse feature
to change their direction. If you are using a standard radio that doesn't
have servo reverse, then you need to remount the servo so the arms move in
the right direction.

To center the surfaces, I hold the surfaces centered with one hand and put
on the servo arms, connected to the rods or cables, so that I have the
surfaces centered as close as possible when I set the arms on. If I have a
screw on/off clevis at the servo end, I will make adjustments so that I can
put the servo arm on and be sitting right at the point where the surface is
centered.

When happy with the position, I set the servo arm and put in the servo arm screw.
If necessary I might add some adjustment at the surface end if it has an
adjustable clevis to further center the surfaces. This is especially
important if you don't have the ailerons or the flaps each on its own
channel. I want them 99% right from the mechanicals.

Only when this is done do I do any final centering using the radio. On my
radios, the menu is subtrim that is used to center the servos AFTER you have
done as much mechanical centering as you can. If each aileron or flap is on
their own channel, then I can do more from the radio for the
final fine tuning.

You can adjust max throws using control horn position but I normally do this
from the radio. I use the radio's ATV/EPA to set the max throws on each
channel.

Then I would decide on what I want for dual rates and exponential on each
channel. Typically I use 100% high with 30% expo and 70% low with 30% expo
as my starting points.

Now, if you don't have flaps and you have your ailerons on separate
channels – 1 & 6 in this example – then you may want to set the flapperon mix
so you can adjust them individually from the radio and set aileron
differential if you like. This also allows you to retask the ailerons as
flapperons for landing.

If you don't have retractable landing gear, some radios will let you put the
second aileron on channel 5, or the second flap servo on channel 5.

Throttle Set-Up

If this is a glow plane, then you use the same procedure to adjust the servo
that will control the throttle. If this is an electric plane, you should
follow the procedure recommended by the ESC maker.

That would be basic set-up.

• Once you get to the field, be sure to a range check before you even think
  about flying
• Make sure you have the right model selected on your computer radio
• Confirm all surfaces are moving in the right direction
• Confirm there is no binding of any of the control rods, cables or the
  surfaces
• Confirm everything is centered

When you do your first flight, ASSUME THERE IS A MISTAKE or that the plane is
out of trim because you are going to have to be prepared to deal with a
problem very quickly.

Once you get it into the air and flying at a good height, then you start to
check the trim and make whatever changes are needed. Remember that a
handling problem may be do to an incorrectly set CG. This might be masked by
adjustments you can make in trim, but that will make the plane fly
inefficiently and may even make it dangerous. So be sure your CG is right as
well.

---

Clear Skies and Safe Flying
Ed Anderson (4/2/06)

This thread can be seen HERE.