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aeajr
477 Posts |
 Posted - 08/31/2006 : 09:28:41 AM
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Setting up an Optic 6 for Full House Sailplanes
by Ed Anderson
aeajr on the forums
I advised a friend of mine to bypass the standard 4 channel radio when he
first started flying. He took my advice and purchased a Hitec Optic 6, a 6
channel midrange sport computer radio. He has been using it for electric
planes, including a 4 channel Multiplex Easy Glider Electric. It has served
him well.
He has done some thermaling and enjoys it. He has also joined me slope
soaring. He has been flying electric planes while I fly pure gliders. Now
he wants to step into the world of 3M full house thermal duration gliders
and maybe, participate in some of our club contests. Down the road he may
even enter some of the regional glider competitions that other club members
fly.
Is his Optic 6 up to the task? Sure!
The Optic 6 isn't a sailplane radio, in the strict sense, but it has more
than enough to get started. The plane he is looking at has 6 servos. It
has two for the V tail which gives him elevator and rudder controls. There
are two for the ailerons and two for flaps. I am going to walk though what
I learned about his radio. Note that I will use sailplane and glider
interchangeably.
In common usage they are the same thing.
I am also talking about thermal duration sailplanes rather than slope
gliders. For our purposes, they are planes that do not have motors which
are launched by some external means with the goal of finding lift in the air
that will sustain the plane in flight. The TD sailplane pilot's goal is to
be able to find lift and ride it for as long as he wishes, then come down
when he wants. If you don't find lift, typically you will have a flight of
2-3 minutes. If you do, flights typically range from 5 minutes to an hour
or more. All without the aid of a motor. It is hunters game, if you are up
to it. Challenging, exciting and relaxing all in the same flight.
If you have an Optic 6, or perhaps a similar class of radio, and have
considered sailplanes/gliders, you can feel confident that your radio can
take you into this exciting style of flying. So, read on, then make the
move to silent, unpowered flight. But be careful, it is highly addictive!
SETTING UP A FULL HOUSE THERMAL DURATION SAILPLANE WITH THE OPTIC 6
I will make frequent reference to pages in the Optic manual. I will assume
this is not your first plane. I expect that you know how to use servo
reverse, end points adjustments, dual rates, expo and can save all your
settings. I also expect that you know how to install servos, hook up
connecting rods and how to adjust them to center surfaces. I am not going
to go into balancing the plane either. All of these are essential to the
set-up, but I expect you know how to do these things.
Let's get started!
Select a new model and set the radio into ACGL mode for Acro Glider
settings. This is your normal setup for fixed wing planes. You select an
unused model and
give it a name.
If you have a standard tail, an X tail, or a T tail, you are set. If you
have a V tail, you select V-tail mixing which is found on page 35 of your
manual.
Based on what I see on the chart on page 5, I would recommend the Hitec
Electron 6 as your minimum receiver. Any receiver with 6 or more channels
should work as well. I will recommend a dual conversion receiver or a high
quality receiver with digital signal processing. These planes are
frequently flown at more than 1000 feet in altitude and can be flown at
almost a mile in range so you want a top quality receiver. No cheapies for
this kind of flying!
Channel Assignments
ailerons on 1&5,
Elevator on 2,
battery plugs into 3
rudder on 4.
Flaps would both go on Ch 6 on a Y cable.
Since your flaps will be on a single channel, you can't use servo reverse to
make one of them go in the opposite direction, so you either have to mount
them in such a way that they move in the same direction, or use a servo
reverser to reverse one flap servo. This is a $20 item.
Go through the usual set-up routine with the radio on to position your
control arms and test all surfaces. Reverse any servos you need to reverse.
The first mix you will need is aileron differential, which is on page 31, to
set up the ailerons on their own channels. Leave up and down equal for the
moment.
Adjust all linkages to get surfaces centered - don't use the radio features
for this yet. Get them as close to centered as possible with the mechanical
adjustments! Also use the holes on the servo arms to get the throws as
close as possible to the desired maximums. Again, we don't want to use the
radio's EPA and subtrim features until we have done this mechanically.
Once this is done,
Then you can use subtrim for final centering
Then you set end points with EPA
Then set dual rates and/or Expo or both to some starting point. I usually
use 70% for my low rates and 30% expo on all surfaces as my starting point.
I always use expo. Love it!
At this point you should have a flyable plane. If you do nothing else, you
should be able to fly it!
GETTING FANCY WITH MIXES
This is where sailplanes get a bit involved. Since we don't have a motor,
and we use a winch or a hi-start to launch the plane, we tend to what to use
the surfaces of the plane to either generate maximum lift or minimum drag at
various parts of the flight. We are trying to suck every bit of energy out
of the air that we can, or to conserve as much of our energy as possible for
thermal hunting and finally for landing. Remember, when a glider comes in
for a landing, it is going to land. There is no going around for another
try! This is skillful flying because there is no motor to save you or pull
you out of a bad situation. This is fun!
I will discuss the mixes I would set up on the Optic 6 if I were going to
fly one of these planes and how and where I would use them. Other pilots
might use different combinations but these are my suggestions. You don't
NEED all of these, but let's explore them.
V-tail if it is a V tail plane- page 35 - we discussed this above. If you
don't have a V-tail, skip this one.
Aileron Differential - page 31 - When we fly gliders we learn that using
both ailerons to roll the plane is good, but that the down aileron can
induce more drag than the up aileron. It can also tend to introduce
something called adverse yaw. So it is common to set the down aileron to a
lesser throw than the up aileron. 50% is typically a good setting for
starters. Some planes don't need this, but most benefit from reduce drag
and better handling. This mix is on all the time and can not normally be
turned off in flight.
Aileron-Rudder- page 36 - Coordinated turns - When you use the ailerons to
bank the plane to redirect the lift, the plane will enter the arc of the
turn. We may use elevator or we may not, depending on the plane. In many
cases the nose will not track true to the circle. This induces extra drag.
By using the rudder, in coordination with the turn, we can bring the nose
around more smoothly getting a better, lower drag turn. Coordinated turns
are also common on power planes but, frankly, since you have all that motor
up there to overcome the drag, many pilots ignore the rudder. Sailplane
pilots love their rudders so much we have the radio add in some rudder
whenever we use the ailerons. I usually start with a 20% rudder setting and
test the plane in the air to see if I want more or less. On most radios you
can turn this mix on and off in the air so you can see if the rudder is
really helping the turns.
Launch/Landing - The Optic 6 has a feature called landing that sets the
flaps and the elevator to a preset that we choose It suggests we use this
for landing purposes but I am going to use crow for that so we can change
the use of this mix to create a launch mix. On launch we want to have the
flaps drooped a bit to create a lot of lift. During the winch or hi-start
launch we can afford the extra drag because the tow line will be pulling the
plane. With the flaps down, say 20%, we can get a much steeper climb on
launch and get much higher launches. So, when we prepare to launch, we flip
the switch and the flaps will go to that preset. Over time we will learn if
we want to add some elevator to this setting, which the Optic allows, to get
the perfect launch.
Crow - page 37 - This is a form of glide path control. We use the flaps,
ailerons and the elevator to change the glide character of the plane. This
is normally used to assist in landing, but can also be used to help us get
out of very strong thermals that might otherwise suck our plane into the sky
and out of view. A reasonable setting would be 80% flaps, 25% ailerons and
about 10% down elevator. This is a very very very plane specific mix so
this will have to be tested carefully in the air as this could be way way
off and make the plane hard to control. Every plane is different. On the
Optic 6, this will be controlled from the left side slider/levers and is
proportional so that we can have full crow, or partial settings so we can
adjust the surfaces according to our desired effect on the plane. I like
the side sliders for landing. I use this to control the flaps on my Futaba
9C, as well as my spoilers for my RES ships.
Camber - page 32 - Camber refers to using the flaps and ailerons in
coordination to change the shape of the trailing edge while we are in
flight. In effect we are changing the shape of the wing, thus changing the
way the plane flies. Common uses are to lower the flaps and the ailerons
slightly to create more of an undercambered wing shape while we are in a
thermal. While this induces more drag, it also gives us more lift. When we
are solidly in a thermal we can afford a little more drag to get that extra
lift so we can draw more energy out of the air and have the plane lift
faster in the thermal.
The other use is to reflex the trailing edge, which means to raise the
ailerons and flaps a little. This can be as little as 1/16 of an inch but on
some planes this will dramatically reduce drag and the plane will pick up
speed rapidly. We lose some lift but this can be very helpful when we are
in a region of falling air, called sink. We want to get out of this area as
fast as possible so we sacrifice a little lift to get though the bad air
quickly.
I believe the camber feature gives us one setting we can control from a
switch. So I will suggest we use it to set a slight reflex setting to get
us through the bad air quickly.
Elevator Flap, also called snap flaps - Page 36 - When we are in a thermal,
we have lots of lift around us. We will be using a little up elevator to
help us climb in the lift. What we can do is set up this mix which will add
a little bit of down flap with we pull up elevator causing more lift from
the wings. As such the plane will climb in a flatter, more efficient manner
rather than angling up the nose to the extent it would normally. This
little bit of extra lift can make a big difference when we are in a thermal.
Normally this setting can be switched on and off in flight as we don't want
this on in normal flight. We will only turn this on when we are in a
thermal. I will suggest about 5% down flaps to start. We will see, over
time, as we tune the plane, if we want more.
Let's walk through a flight:
Launch - Flip that switch for our launch setting and send the plane up the
launch line. At the top of the launch we will turn this off so that we are
in normal cruise mode. We are now 400-600 feet up and looking for lift.
Let's go hunting!
We spot some lift and we start to circle. We flip on Elevator-flap mix,
E-F, so when we pull elevator slightly, we get a tiny bit of flap to help us
climb smoothly in a thermal.
We lose the lift so we turn off E-F and go hunting again. We hit some fast
falling air, sink. We want to run through some sink, so we flip our
camber/reflex preset on, flaps and ailerons move up a little, and the plane
moves quickly through the sink. When we are in more buoyant air we flip
this off.
We catch some lift and circle up again and turn on E-F to rise in the
thermal. We have been in this thermal for 20 minutes or so. We hit about
1000 feet and have ridden the thermal about 1/2 of a mile down wind. Time
to head home and prepare to land. During our return run we will fly in
cruise or we might turn on that camber/reflex preset again to help us
penetrate through the head wind. Remember we have no motor so we are flying
upwind in a glide.
OK, time to land. We set up for an approach into the wind. We want to have
more energy than we need to make it to the landing mark because a gust might
hit us and rob us of energy causing us to fall short. As we finally get
close and are confident of making the landing zone, we can start to use that
Crow mix to lower flaps, raise ailerons and mix in elevator to keep the
plane level or slightly nose down. As we judge our speed we may go full
crow to "put on the breaks" so that when we touch we are moving slowly and
will not overshot our mark.
Cool?
Yep, the optic 6 can fly that plane, and we still have two user definable
mixes open to try some other fancy stuff. Super Cool! :-D
Try Gliders. This is a very different form of flying. If there is a hunter
in your heart, this is for you. If you enjoy fishing and can understand the
quiet before the strike, then the excitement of landing the fish, this is
for you.
Other Resources
Crow on the throttle stick, and other Optic 6 tips
http://www.rcgroups.com/forums/showthread.php?t=451555
Sailplanes are Wonderful!
http://www.rchangout.com/forums/showthread.php?t=5356
A sailplane in lift
http://www.rcgroups.com/articles/liftzonemag/2004/mar/ava/Ava2.wmv
If you are not familiar with thermaling, take a look at this thread.
Finding elusive thermals
http://f4bscale.worldonline.co.uk/Thermals.htm
The Soaring Methods of Birds
http://www.apogeerockets.com/education/Soaring_methods.asp
What do thermals look like?
http://www.flyaboveall.com/mountainpilot/thermalclinic.htm
Sailplane terms - Useful reference thread
http://www.rcgroups.com/forums/showthread.php?t=185385
If you don't understand the launch phase, this thread might help. Learning
to use a hi-start
http://www.flyesl.org/forums/topic.asp?TOPIC_ID=216
Best Regards,
Ed Anderson
Best regards,
Ed Anderson
aeajr on the forums
Long Island Silent Flyers |
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aeajr
477 Posts |
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Topic |
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Setting-up the Optic 6 for Full House Sailplanes
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