Fly Sky FS-i6 Manual

1 12April 2019
Set-up of
FlySky FS-i6 Transmitter(Tx) and FS-iA6B Receiver(Rx) for
DF65 RC Racing Sailboat
(David Flakelar)
Background
The FlySky FS-i6 system operates under the Digital Proportional Protocol using an Automatic Frequency
Hopping Digital System. It is a pulse digital system on carrier frequencies unique to a particular transmitter.
You don’t need to know how that works. The manufacturer claims there is no risk of interference from
another transmitter.
These notes are written to help the beginner set-up the FlySky Tx/Rx system to operate with the DF65.
There are also a few tips that have nothing to do with the FlySky system but may be of interest.
Feedback would be much appreciated.
Why I Bought the FlySky TX/Rx System
1. It appears to be used by most of the fast sailors!
2. The marginal cost is the cost of FS-i6 system less cost saving on buying DF65 without Tx and Rx.At
current Hobby Warehouse prices this represents an extra cost of (76.4-(237-179)) which is $18.
3. Minimal risk of interference from other sources.
4. Using its built-in telemetry capability, the condition of both batteries is displayed on Tx monitor.
Visual and audible alarms can be set.
5. Expo (exponential) and or proportional control can be used on rudder movements
6. Winch action can be desensitised
7. Using Dual Rate alternate rudder settings can be established.
Compatibility
The FlySky Tx will only operate with a FlySky Rx of which there are several types. The Turnigy and Park
Fly products appear to be FlySky re-badged?
Instruction Manual
A 27-page Instruction Manual is available from the web.
On registration with Gearbest, a slightly larger FS-i6 manual is available. Some DF65 packs come with the
manual on a disc.
There are a number of videos available on YouTube. Most of these relate to control of model aircraft.
Search on “FS-i6/DF65”.
Switching Sequence
Having assured the user there is no risk of interference from another radio frequency source, the maker
recommends that a particular switching sequence be observed, which is: Tx ON, Rx ON: Rx OFF, Tx OFF.
FlySky Product Range
The DF65 requires only a two channel Tx to control rudder and sail winch.
The FS-i6 is a 6 channel controller and the FS-i6X provides 10 channels.
The supplied Rx is the FS-iA6B with 7 ports and for neatness the three cables (battery switch, rudder and sail
winch) plug-in horizontally from the end. A FS-iA6 Rx is available and has the same functionality but the
seven ports are arranged vertically with exposed pins. Depends how you want to arrange cabling.
FlySky Operational Range
The physical range of the FS-i6 is dependant on the condition of batteries, orientation of both Rx and Tx
antenna ie. the way the Tx is held. The Rx has two antenna and their orientation should match the
manufacturer’s instructions. However, range should never be a limiting factor for DF65s. The FlySky
system has been shown controlling a drone out to 2.3km.

2 12April 2019
Line-of-sight transmission is important at all times.
Screen Saver
The screen brightness can be refreshed by pressing any button.
Warning
When switching on, if switches are not in their correct position, screen and audible warnings are provided.
Binding
As explained above, each Tx has a unique ID and the slave Rx must be programmed to process only those
signals from the master transmitter.
The maker advises the supplied Tx/Rx combination is already “bound” but you may wish to operate two or
more Rx from the one Tx. Hence the need for further “binding”. To bind a second Rx you must first select a
new model no. This is explained below.
Both the Instruction Manual and YouTube tutorials are clear enough as to how binding is done. Follow the
sequence exactly.
With batteries loaded and Tx/Rx switched ON and before binding, a red LED on Rx will flash. This becomes
steady when binding is complete.
Incidentally, the FlySky system provides for the control of up to 20 models which means you could have up
to 20 DF65/95s (or aircraft) set-up independently and therefore each would require separate binding.
Binding Procedure
1. Rx should be adjacent Tx
2. Insert battery in Tx but do not switch on
3. Insert binding cable into B/VCC port on Rx
4. Insert Rx battery into any port (Ch1-Ch6). Red LED will flash indicating the Rx is not bound
5. Hold down BIND KEY on Tx and switch on Tx - labelled POWER
6. Release BIND KEY when binding is complete. The Red LED will remain steady
7. Switch off both devices
8. Remove the binding cable.
9. Remove Rx battery lead and insert in Rx B/VCC port
10. Switch on both devices in the correct sequence. Red LED will be steady
FS-iA6B Receiver Connections
FS-iA6B
B/VCC
◄Battery Switch Cable: (Red & Black. Black lead down)
Ch 6
Ch 5
Ch 4
Ch 3
◄Winch Cable: (White, Red, Black Black lead down)
Ch 2
PPM/Ch1
◄Rudder cable: (Pink, Red, Brown. Brown lead down)
Note that labels shown on Rx do not exactly align with ports below

3 12April 2019
Settings
FS-i6 Tx has six channels and therefore offers six controls that presumably are required to operate a
quad copter. Only two are required for the DF65 –to control rudder and sail winch. These two
controls are variously referred to as the gimbals, control sticks or stalks. Most sailors use the left
hand stick (North-South) to control the winch and the right hand stick (East-West) to control the
rudder. These can be reversed using the Sticks mode in System Menu. Additionally, the rudder
control can be reversed so that it operates like a tiller. Select Ch 1 (rudder) and Reverse in menu.
There are four buttons on the Tx that are used to navigate through the menu and establish winch and
rudder settings. The menu is arranged in a hierarchical structure. The four buttons and their
function are:
OK
Press to activate the displayed screen so that setting changes can be made. To
select MENU a long OK is required.
CANCEL
Short CANCEL to cancel any changes and exit the screen. Default screen will be
the screen at the next level. Use a long CANCEL to save any changes to the
current setting/s.
UP
Change the displayed or selected parameter upwards
DOWN
Change the displayed or selected parameter downwards
It is helpful to navigate through the menu to become familiar with the use of the buttons and the
range of settings. Use a Model No. that is not in use. Alternatively, Exit the screen with a short
CANCEL to ensure any changes made are not saved. A long CANCEL will save any changes.
FlySky Menu
The MENUs are selected by switching on Power and holding down OK. Two choices become
available: System set up and Functions set-up. Toggle between these using UP/DOWN buttons.
Exit progressively to main display at any time by Short CANCEL. Changes made at any point are
saved by Long CANCEL ie. holding down CANCEL button.
Switch A & B and Trim Tabs
The main screen is shown in my manual on page 13. It does not show controls that will be referred
to later. Switch A, labelled SWA (top left of Tx) is used for Dual Rate set-up and SWB is used
for Throttle curve. There are two stick trim tabs used for fine tuning. The winch trim tab is
to the right of the winch stick and the rudder trim tab is below the rudder stick. Both have an
audible tone to indicate direction and mid point. Both can be used for fine tuning. The trim tab mid
range position can be seen and controlled in Display.
Selecting Model
The example below shows the steps required to assign your DF65 A+ rig to Model 10 in FS-i6
system
Action
Result on Screen
1
Power up Tx
Main screen
2
Long OK
MENU
● System (Crown icon)

4 12April 2019
Action
Result on Screen
●setup (Spanner icon)
3
Using UP/DOWN buttons select
“System”
System icon boxed
4
Short OK to select this SYSTEM
MENU
SYSTEM
Model select
Model name
Type select
etc.
5
If necessary, use UP/DOWN buttons to
select Model select
SYSTEM
Model select
Model name
Type select
etc.
6
If necessary, use UP/DOWN buttons to
select required mode
Model select
Model 10
Flysky 10
Aircraft icon
7
Short CANCEL to exit next screen
SYSTEM
Model select
Model name
Type select
etc.
8
Long OK to select and use UP/DOWN
buttons to select Model name
SYSTEM
Model select
Model name
Type select
etc.
9
Short OK to select
10
Using cursor, and OK button, type
model name “DF65 A+”
Model Name
Model 10
DF65 A+
Alphabet
11
Exit to upper level with short CANCEL
and select “Type select”
MENU
Model select
DF65 A+
Type select
12
Short OK to select Type of Aircraft
MENU
Model select
Model name
Type select
13
Use UP/DOWN buttons to select

5 12April 2019
Action
Result on Screen
Airplane or Glider
14
Short OK to select Airplane
Or Glider
Type select
Model 10
DF65 A+
Airplane or
Glider
Aircraft icon
15
Long CANCEL to save and several short
CANCELs to exit to Main Menu
Main screen
Weather Helm Discussion
These musings are meant to provide some background to the set-up of the DF65 winch and rudder
using the FlySky system.
When racing, ideally, in steady-state conditions, we want the boat to track in a straight line
particularly to windward with slight weather helm. If there is too much weather helm the boat will
round-up and go into irons.
There are a number of measures theoretically possible to achieve balance:
1. Constant and skilful rudder movement will provide straight line tracking however rudder
movement is slow as the rudder when used provides a greater projected area. It acts a bit
like a brake.
2. Mast rake by adjusting forestay and backstay tension. By this adjustment the sail’s
combined Centre of Effort (CE) can be moved fore and aft relative to the foil’s Centre of
Lateral Resistance (CLR). By this we are essentially controlling the couple between these
two forces. There is plenty of reading on the internet and elsewhere about this and wont be
repeated here. Generally a small amount of weather helm is safer and it is desirable to
provide a bit of feedback to the helmsman otherwise the steering will feel dead. The latter
does not apply to RC yachting.
There is no known, easy way of setting up optimal mast rake except by trial-and-error. The
recommended measurement from a reference point on the upper mast to a point on the deck
is about all there is. This method is a guide only and not very accurate. See Soch Sails
DF65 Rig Tuning Guide.
3. Changing the CLR by lifting the centreboard/keel (impossible with DF65)
4. Reduce the power of mainsail by easing main sheet (more of this later), flattening foot or
ease boom vang to soften leech (ie. spill more wind from back of sail)
5. Reef main
6. Increase power of jib by moving its CE forward and thus moving the entire rig CE forward
In an RC yacht a bit of weather helm is desirable, not for feel, but for another reason. When
moving through the water the foils provide lift. This is analogous to the wing (foil) on an
aircraft, particularly a glider. The downward gravitational force of the glider is balanced or
counter-acted by the lift provided by the wing. One approach with DF65s might be to use
the Trim tab referred to earlier and this might be a quick fix on one tack however it may
have to be removed or re-applied on the other tack. There is no known way that an RC
yacht can be provided with an offset rudder to provide the required minimal amount of
rudder on both tacks.

6 12April 2019
The only way an RC yacht can move in a straight is by the accurate alignment of CLR and CE.
However any particular setting is only good for a particular set of wind and wave conditions. And
may only be good for a particular tack.
In a wind gust these balanced forces become out-of-balance. The wind force on the sails increases
with the square of the wind velocity but the counteracting force from velocity of water over the foils
does not increase because in the instant the gust hits the boat speed has not increased and the boat
rounds up.
The second impact of a gust is to heel the boat. The underwater shape of the hull changes from one
that is symmetrical (when mast is vertical) to one where the line of least resistance is for the hull to
move to weather. So to counter the boat rounding-up, rudder is used to force the bow down. But as
the hull heals the rudder has less effective area in the direction of travel and more and more rudder
has to be used. Any rudder movement slows the boat because of Newtons First law and the greater
the rudder movement the greater the impact on speed. In short, any rudder movement is slow.
The other means of countering the effect of a gust is to ease the sheets for the duration of the gust
and a way of doing this is by a Throttle curve set-up using Switch B –Winch Control. It is
acknowledged that the sheets can be eased with slight winch movement at any time –SWB just
might just make it easier and more consistent.
Also in a gust the apparent wind moves aft and as we have suggested, the impact on heeling-over
and rounding-up can be minimised by easing sheets and increasing velocity. However this is not
the only possible response. Theoretically one could remain close-hauled and benefit from this
velocity lift by sailing a slightly higher course. In a dinghy this is often possible by hiking harder
and thus keeping the hull flat.
The recommended response to a wind gust is to slightly ease sheets although this needs to be
contested.
No recommendation is made regarding taking the velocity lift and I would welcome feedback for
further dissemination
Rudder Use Discussion
If during the starting sequence or when racing in a variable wind, and the boat is above close-hauled
and either stationery or moving slowly, like a dinghy, it is possible that by sculling, she may be
brought down to a close-hauled course. This does not violate RRS 42 Propulsion. See RRS 42.3
(d). That is, if the hull lies above close-hauled on the Port tack, by moving the rudder stick to the
left and releasing so that the spring loading moves it to the centre neutral position, the scull may
force the bow down to close-hauled.
This suggests the rudder End points setting may have to be greater than that required for normal
steering.
It is essential to have a physical mid rudder reference point on the underside of hull so that before
launching one can determine whether the rudder is physically aligned fore and aft. To establish this
neutral rudder reference point, remove rudder and turn the hull upside down. Carefully align a
straight edge between centre of keel and centre of rudder post opening. Using a fine permanent
marker, draw a short line aft of the rudder trailing edge position. This will be a reference for a
neutral rudder.
Assuming a 35 degrees rudder throw say, and using a protractor or 30/60 set square, mark the
position of the trailing edge of rudder when helm is hard over - both tacks.
If there is any rudder slop, insert a short length of rigging line into the rudder post hole and trim
excess later. Replace rudder and secure after carefully aligning with neutral helm marker. Ensure
rudder moves freely.

7 12April 2019
Starting a Race - Discussion
There are fundamentally two ways of starting in a yacht race.
A displacement yacht will usually start coming from distance because their inherent design and
weight means they cannot easily be parked and subsequently accelerated away. The primary skills
are to pick the right lane, at the right end, (consistent with line bias and whether the right, or middle
or left hand side of the course is likely to be favoured) and judge the speed of advance on distance
so that the boat is at speed, in clear air, just behind the line when the gun goes. Simple.
The start of a dinghy race is usually fundamentally different. In say a quality Laser start, once the
position on the line is determined, the boat is “parked” about one boat length back from the line and
held in position by mainsail trim so the leech just catches the wind. This together with judicious
sculling with the rudder the dinghy can be parked so as to not move down the line onto other boats
to leeward. Weather boat keep clear!
The process is, about n seconds from the start, where n will depend on the type of boat and how
well it accelerates, simultaneously quickly sheet-on, hike to keep the boat flat, and as the boat
accelerates, pull-away to close hauled. This procedure is preferred to the keel boat type start
because the need to judge time on distance is minimised.
It is not known which is best for the DF65? Maybe a mixture of both.
End Point Settings
Operation of the DF65 requires setting limits to (i) the number of winch rotations between fully
sheeted in and fully sheeted out and (ii) the angle through which the rudder moves. This is done by
using the menu to set-up the End points.
Winch (Ch 3): Use this setting to set the winch throw to about 115mm of sheet. More later.
Rudder: (Ch 1): Use this setting to set the maximum rudder throw in both directions which should
be about 35 degrees or perhaps more if you intend to scull. Too much rudder movement when
underway may cause the rudder to stall.
How To Set-up Winch Throw
Power-up Tx.
If necessary, select model number as described above.
Ensure that bowsies for both sheets are fully released. Better still, remove sheets from sheet clip.
Using the Function set-up menu, go to End points
Using short OK, index through to Ch 3 in left hand column.
This should be the sheet-in position.
Sheet Out with stick so that sheet clip is at the fwd end of hatch opening but well clear of main
sheet bridle. It may be necessary to add or remove a turn or two from the winch drum. Mark this
Sheet Out position of the sheet clip with a fine point marker. Sheet In and mark this position of the
clip. It should be about 115mm from the Sheet Out position.
If not, use UP/DOWN buttons to adjust either position.
In the Sheet Out position attach sheets to clip, Sheet In and use bowsies to set both booms to their
recommended positions.
Check Sheet Out position of both booms.
Use long CANCEL to save this setting and index out to main menu with short CANCELs
Move stick to Sheet Out position and repeat above checks if necessary.
Incidentally, the winch speed can be increased by increasing its effective diameter by winding more
line onto the drum during the original set-up.
Normally the sheet would be wound onto the drum in a clock-wise direction. If wound counter-
clockwise, use the Reverse setting on channel 3 to reverse direction of travel.

8 12April 2019
How to Set-up Rudder Throw
Power-up Tx/Rx
If necessary, select model number as described above
Using the Function set-up menu go to End points
The default should be Ch 1 (Rudder) in left hand column
Push rudder stalk to left and hold, rudder should follow
Using UP/DOWN button, fine tune rudder position so that it aligns with pre-set 35 degrees guide
Move rudder stick to right and repeat tuning in right hand column
Long CANCEL to register these settings and index out to main menu with short CANCELs
Check to ensure you have selected the correct model.
Check rudder throw and ensure rudder is in mid ships position
Power off
Rudder Mid-Point and Weather Helm
It is not uncommon in a steady breeze for the DF65 to sail to windward perfectly balanced (ie. no
rudder adjustment necessary) on one tack but to have a marked tendency to round-up on the other
tack ie. weather helm. This may be due to asymmetrical sheet settings and this should be checked,
particularly the position of main sheet bridle on both tacks. It may also be due to the rudder being
slightly off centre. This mid-point can be reset during racing by the rudder trim tab below the stick.
When used, the audible tone indicates the direction of movement and the mid position.
Alternatively when not racing the rudder mid-point can be set using Ch 1 Subtrim and the
UP/DOWN buttons.
Rate
In its factory setting, rudder movements are proportional or, if you like, linear. A 50% movement of
the stick to the right will result in a 50% movement of the rudder to the right, within the preset
range.
There are two ways of controlling the relationship between stick movement and rudder movement.
The first is Rate, the other is Expo. They can be used alone or together. When Rate is used,
for a given stick movement, the rudder will move through a smaller angular displacement than if
there was no Rate used - but the relationship remains linear.
Strictly speaking it is not a “rate” which implies it is time dependant. Rather, Rate changes the
extent of rudder movement. The default is 100. If set to 50 then a movement of 50% of the stick
range will result in (0.5X50=) 25% of rudder movement. In effect, it desensitises stick movement in
a linear way, but over the entire stick range. The other important consequence of the use of Rate is
that it effectively reduces the rudder throw. If the rudder end points were set at 35 degrees say then
the use of a 70% Rate would effectively reduce the throw to (0.7x35=) 25 degrees. So use this
setting with care.
How to set-up Rate is explained below.
Expo (exponential) Control
Expo is the other way of controlling the relationship between stick and rudder. Rate and Expo
can both be used to control rudder movement, either singularly or combined together. A second set
of Rate/Expo settings can be use using Switch A (SWA)to invoke the Sports mode. More later.
With the use of Expo, the stick/rudder relationship changes to one that follows one of a
theoretically infinite number of exponential curves. For example with Expo, a 50% stick

9 12April 2019
movement to the right (or left) might result in only a 30% rudder movement –depends on the Expo
setting. More rudder movement leads to proportionally higher response.
The extent of Expo applied is a matter of personal preference.
So both Rate and Expo alter the default linear curve to one that either is less sensitive (positive
expo) or, more likely, more sensitive (negative expo) around the middle range. When using Expo,
a typical starting point might be 30%. - depends on whether Rate is also used.
What is Dual Rate and Why it May beAppropriate for DF65
The FlySky rudder settings allow control of the rudder throw (End points) and sensitivity
(Rate and/or Expo). Using Switch A (SWA) to invoke the Sports mode a second set of
Rate/Expo settings can be selected and saved but only one set of End points can be used.
How to Set-up Dual rate/Exp. ForAlternative Rudder Control
Power-up Tx/Rx
Select model number as described above
Using the Function set-up menu, and short OK, index through to Dual rate/expo. Select
with OK
Short OK on Ch and if necessary index to Ch1 (Rudder is selected)
Throw Switch A (down) and Sport will be displayed
Set-up Rate using Up/Down buttons. Index to Expo and again using Up/Down buttons select an
Expo setting.
Long CANCEL to save.
Experimentation on the water should give an indication of the optimal rudder settings for Sport
mode. Depends on its intended use.
Control of Winch in a Gust –Use of Throttle curve
In the discussion above it was suggested that the most appropriate response in a gust is to ease
sheets rather than use the rudder to counter the inevitable rounding-up. Of course with fine motor
skills, sheets can be fractionally eased at any time however it is suggested that a desensitised winch
may be appropriate. This can be set-up using Throttle ease and Switch B (SWB). The curve
should be not be dissimilar to that used in the Rudder Sports mode. At Position 1 I have used 8%.
Model Copy
This function can be used to copy Settings on one model to another. Any settings on the target
model will be over-written.
To copy, Model 3 to Model 4 say, ensure Model 3 has been selected. This becomes the source
model
Select System menu and index to Model copy
Select Target model and long CANCEL to save, then several short CANCELs to return to main
screen
Check settings on target model
Model Reset
As the Manual says “This function will reset selected model settings to default.
The other models will be not be affected. This can be useful when a set-up is going nowhere and
needs a fresh start.

10 12April 2019
Other FlySky Functions
The FlySky system provides the rich functionalty required for model aircraft and many features
have no relevance to RC yacht racing. However some may be useful. Not described here are
Model name, Model reset, Sticks mode (useful for changing from wheel operation to
tiller operation), Rx battery alarms, Factory reset, Reverse stick operation
for left handed sailors, Display (mid position and end points of all channels) and Sub trim.
Refer Manual for more details.
Disclaimer
The Dual Rate features of the FlySky system have been described to highlight the available
functionality. It does not follow they should be used. Moreover the suggested setting are nothing
more than that. Personal preference and experience are the best guide. I’d like to draw on that
experience and over time I’m sure the best techniques and settings will evolve.
I’m mindful of my experience with a compass on a Laser. When first used, I spent an inordinate
amount of time watching the compass and far too little time watching the big picture ie. getting my
head out of the boat.
So, any speed gain made by using say Throttle curve in gusts during the race may all be lost
in one bad mark rounding.
Concentrate on the important things first.
All will become clear over time as gifted sailors develop and refine what is fast for this class and
provide feedback to the plodders.
David Flakelar
Questions and feedback would be very welcome. Email preferred [email protected]
Mob [phone] or [phone].