How to Program Airbrakes
for the Delta Vortex - An Overview
by Bruce Tharpe
I've had some questions about how to program the airbrakes
on the DV. By airbrakes, I mean the rudders both deflect
outward with the flip of a switch, thereby creating drag
to slow the model quickly during a landing approach. They
work great on the DV! It takes a pretty high-end radio with
plenty of mixing capability. Personally, I set mine up with
an old Ace Micropro 8000, which very few people use. Point
is, I can't give specific instructions for specific radios
that I don't use. However, the concept is universal and
with some "figgerin" and head scratching, I'm sure most
builders can do the actual programming. Stick with me now...
For rudders, airbrakes, and nose wheel steering, you need
three servos - one on each rudder and one for the nose wheel.
Each servo must be plugged into a separate receptacle on
To make this all work, you must program four different custom
"mixes". Each mix involves two channels; one will be the
master and one will be the slave. The four mixes are as
MIX 1. Rudder Servo #1 (master) -> Rudder Servo #2
(slave) This simply makes the rudder servos work together
as rudders. They should move in the same direction, using
the rudder stick on the transmitter.
MIX 2. Rudder Servo #1 (master) -> Nose Wheel Steering
Servo (slave) This is to control the nose wheel servo with
the rudder stick on the transmitter, as usual.
MIX 3. Airbrake Channel (master) -> Rudder Servo #1
(slave) You can choose which channel you wish to use for
airbrakes. The easiest is probably the retract switch, but
you may prefer a flap knob or some other switch on the transmitter
that is not being used.
MIX 4. Airbrake Channel (master) -> Rudder Servo #2
(slave) Same as above. The rudders should both deflect outward
when the airbrake channel (retract switch) is activated.
You should still have some rudder control when the airbrakes
Programming the Futaba 7CAP
Submitted by BTE Customer Barry Whiffin
Thanks again for a great kit. The split rudder airbrakes gave me some
serious trouble using a Futaba 7CAP transmitter. This is due to it only
providing 3 Mixers and not the 4 Mixers you give in your website example.
This is a popular transmitter and I thought this solution might be of use to
you and your customers. It also provides the added benefit of being able to
mix elevator in with the airbrakes without any additional hardware mixers.
My solution for the Futaba 7CAP is to use the following:
Channel 1 = Left Elevon
Channel 2 = Right Elevon
Channel 3 = Throttle
Channel 4 = Rudder 1
Channel 5 = Nose Wheel In param menu set Chan5 to -- (no switch)
Channel 6 = Rudder 2
FLAPTRIM = ON 0% 0% (This stops the Chan6 knob operating only Rudder2)
PMIX1 4>5 SW -- (Rudder1 to Nose Wheel and always ON)
PMIX2 4>6 SW -- (Rudder1 to Rudder2 and always ON)
PMIX3 OFS>4 SW G (Allows Rudder1 to be offset using the airbrake switch G)
So when I throw SW G and activate the Airbrakes (Rudder2 on Chan6) the same
switch G also activates PMIX3 Rudder1 with an offset. The result is both
rudders move on the same switch G.
The bonus is that due to using the Airbrake function I can also go to
A.BRAKE settings and dial in an elevator correction should one be needed
during airbrake deployment.
Only problems I can see are
1. that the trim lever on Rudder1 only moves Rudder1 on Channel 4, not Rudder 2.
2. the amount of Airbrake on the Rudders has to be adjusted in two places
(A.BRAKE and PMIX3).
Programming the Futaba 9C
Stumbled upon by Bruce Tharpe
Futaba-RC.com offers detailed instructions in their FAQ section, just click the link
below. If you are a 9C user (like me), you will find a wealth of info there that will help
you get the most out of your transmitter.
How do I set up the 9C for a delta wing with dual rudders? Can I use the dual rudders as airbrakes?
Programming the Futaba 8U
Submitted by BTE Customer
"Bruce, Using the '8U' Futaba transmitter, here is one way
to make both rudders work together and also to be able to
throw a switch to make them act as airbrakes and to allow
the nose wheel to turn:
4 = RIGHT RUDDER
5 = GEAR SWITCH E (NOT PLUGGED IN ON THE RECIEVER)
6 = NOSEWHEEL
7 = LEFT RUDDER
#1 MIX = Makes the nosewheel move with the right rudder.
#2 MIX = Makes the left rudder work with the right rudder.
#3 MIX = Using this switch activates the right rudder to
be an airbrake.
#4 MIX = Using this switch activates the left rudder to
be an airbrake.
Hope this makes sense to you. It works for me.........Tony"
Programming the JR 8103
Submitted by BTE Customer Scott Orten
"The kit was great. I have been building kits since the early 80's and found that your
instructions were great and your building tips told me things I had not known or done before.
"I had a big problem finding someone to help me program my JR 8103. After several calls to the
people who did the magazine articles and several calls to JR, I finally got a call back from JR.
"Thanks again for a great model."
Elev - Adjust for rudder compensation
Flap - D170
Spoi - INH
Auto - INH
Mix 3 Aux3-Aux3
Rate -100, -100
Mix 4 Rudd-Aux3
Rate +100, +100
Mix 5 Flap-Rudd
Rate -100, -100
Mix 6 Rudd-Flap
Rate +100, +100
Aux3 +100, -100
Flap +100, +100
Rudd = Left Rudder
Aux1 = Right Rudder
Aux3 = Nose Wheel Steering
Programming the Spectrum DX7
Submitted by BTE Customer Lloyd Roberts
AILE = Left Elevon
ELEV = Right Elevon
RUDD = Throttle
AUX1 = Left Rudder
AUX2 = Steering
MIX 1 Activates Nose Wheel Steering
RUDD>AUX2 - ON
MIX 2 Activates Rudders to Work Together
RUDD>FLAP (FLAP=AUX1) - ON
OFFSET: Adjust for Equal Travel
MIX 3 Activates Air Brakes Using GEAR Switch on Transmitter
GEAR>RUDD - ON
Bruce's Comment: Buyer beware! I have modified Lloyd's original instructions slightly, because
he needed to use the GEAR switch for the retractable gear on his DV. Instead, he used the FLAP MIX
switch on the transmitter, which is a three-position switch and introduces a serious problem.
Flipping the FLAP MIX switch the wrong direction would deploy only one rudder, a mistake you would
not want to make on short final. So I strongly suggest you use the GEAR switch, although the
programming shown above is not proven and may require tweaking.
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