Basic Acro Programming

8FG Quick Set-Up Guide for Electric Fixed Wing Aircraft (courtesy RCG user myp)

When I first got the 8FG (I came from using a Spektrum DX6i and, briefly, a Hitec Aurora A9) in August 2011, I found that the 8FG user menus and its manual were not well organized compared to that of the DX6i and the A9. In fact, some might consider the 8FG menu and manual very dis-organized and cryptic. If you are moving from the A9 to the 8FG, you would feel like moving from the 21st century to the Middle Ages. So my goal is to write a step by step guide to enable someone new to the 8FG to set up a fixed wing aircraft quickly.

I will describe how to set up a fixed wing, 2 aileron servo, normal tail electric plane. I followed these steps to set up my 3D Hobby Shop 59” Slick, a 3D plus IMAC pattern plane.

Note that the 8FG is a very flexible transmitter. Therefore, there is usually more than one way of accomplishing a setting. I am just describing one way in this set of notes.

I am assuming that readers of this guide fly electric airplanes, are familiar with programming a computer transmitter, understand concepts such as Fail Safe, Dual Rate, Expo, End Points, etc. Since this is a Quick Set-Up guide, it is not a comprehensive set of notes on all the features of the 8FG. For that, you should refer to the 8FG manual and the excellent companion notes to the manual written by Malcolm Holt. Finally, since I fly only fixed wing electric aircraft, my notes do not apply to glider or helicopter.

Navigating the Menu

1. The Control Buttons/Ring

  • The control ring on the bottom right hand side of the transmitter has 5 “buttons”: SYS, LNK, MDL, S1 and in the center RTN. Tapping SYS, LNK, or MDL twice in quick succession at any time brings you to the corresponding SYSTEM, LINKAGE and MODEL menus. RTN is the equivalent of SET, OK or SELECT button on other systems.
  • S1’s main use is to return to the main screen. Pressing S1 at any time more than 1 second brings you to the main screen. Tapping S1 once in a menu with multiple pages will advance the menu to the next page.
  • LNK and MDL let you set model related attributes. I am not sure why two menus are needed since all items in these two menus are related to a model.
  • SYS lets you set up display related attributes (e.g. how long the backlight stays on, the default warning sound, etc.) and show you the Firmware version info. I suggest that new users not worry about the SYS menu as the default settings will work for most pilots.

2. Moving Around and Selecting Item

  • Circling your finger clockwise or counter clockwise on the control ring allows you to move up, down, left right on menu items. When you stop at an entry, it is highlighted. Pressing RTN will select the item and bring you to the menu representing that entry.
  • It also allows you to change the value of an entry (e.g. Expo). Usually, circling clockwise increases a value and circling counter-clockwise decreases a value.
  • When the menu name (e.g. LINKAGE) is highlighted, pressing RTN returns to the previous menu. In this example, the main screen.

Setting Up a New Model

Selecting a Model

  1. Go to the main screen and select model name in the main screen. For a new 8FG, it will be “MODEL-01”. Press the RTN button.
  2. You will be in the MODEL SEL Screen. Select NEW and press RTN. A message now appears at the top of the screen telling you to press RTN for 1 second. Do that.
  3. This will take you to the MODEL TYPE screen. For our purpose, set TYPE to AIRPLANE, WING to NORMAL and 2AIL, and TAIL to NORMAL. Press RTN.
  4. The next screen you see is the FREQUENCY screen. If you bought the 8FG (Super) with an 8 channel receiver, the default Multi2 mode is good for the R2008SB receiver. I don’t understand the reasons for three modes but I assume it is because Futaba did some enhancements that are not compatible with old transmission protocols. Just treat this as a nuisance for now.
  5. If you want to use other 8 or more channels receiver, Multi2 is good too.
  6. If you have a 6 or 7 (e.g. R617F) channel receiver, select FASST and change the default Multi2 to 7CH.
  7. Press RTN and this will bring you back to the main screen. Your new model is called NEW1.

Renaming your Model

  1. From the main screen, select NEW1 and press RTN.
  2. You are now in the MODEL SEL screen. Select RENAME and press RTN.
  3. Remove NEW1 by moving the cursor to the before the first letter (“N”) and pressing DELETE. Repeat for “EW1". Once NEW1 is removed. Move the cursor to the first letter (on the right side of the screen) of the name you want to give to the model. Press RTN. Repeat until you have named your model.
  4. Press S1 for a second to go back to the main screen.

Making Sure that the Control Surfaces Moves in the Correction Direction

  1. Go to the Linkage Menu by tapping LNK twice. Select REVERSE and press RTN.

IMPORTANT. The throttle channel must be reversed! Do it now before switching on your power system or you could be surprised. This seems to be an idiosyncrasy of Futaba transmitters – default full throttle is the stick at the bottom. Select THR and set it to REV.

  1. Move your control surfaces and see if they move in the correct direction. If they do not, select the value associated with control surface and set it to REV.

Selecting the Model Type

Setting Your Servo Arm to be Perpendicular to the Control Linkage

  1. By setting your servo arm to be perpendicular to the control linkage, you will have a good chance that Up/Down or Left/Right movements of your control surface will be symmetrical. First, make sure that your servo arm and control linkage are mechanically as close to perpendicular as possible.
  2. Make sure that your TRIMS are all set to zero.
  3. Go to the Linkage menu and Select SUBTRIM.
  4. Select, say, Elevator and change the Subtrim value so that the servo arm and the control linkage are perpendicular to each other.
  5. Do this for Aileron, Aileron 2 and Rudder.

Setting End Points

  1. End points can be used to make sure that Up/Down or Left/Right movements of control surfaces are symmetrical. It can also be used to make sure that a control surface can deflect to a desired position.
  2. Go to the Linkage menu and select END POINT.
  3. Note that there are four numbers (percentages) for each control surface. Initially, these numbers are 135, 100, 100 and 135. The first and last numbers indicate how much the control surface can deflect with mixing. For now, we can ignore them and focus on the second and third numbers. Each of these two numbers represents how much each control surface can deflect in each direction respectively. I like to set up mine so that they are at maximum to get the maximum resolution of the servo. For example, 3D Hobby Shop suggests that the elevator for the 59” Slick should have 55 degrees plus and minus. So I set the two middle numbers to 135 and see how close they are to give me 55 degrees. It turns out that even at a value of 100, I am already getting 50 degrees of deflection. So, I ended up only setting both numbers to 115. For my plane, they are the same since I have already gotten the servo arm and control linkage for the elevator to be perpendicular to each other mechanically and with SUBTRIM.
  4. Note that 8FG allows you to set 140 as the maximum for the middle two numbers.
  5. Repeat step 3 for Aileron, Aileron 2 and Rudder to their desired deflections.

Setting Dual Rates and Expo

  • The 8FG allows 5 rates each for Aileron, Elevator and Rudder. What’s more, rate 5 has priority over rate 4. Rate 4 has priority over rate 3 and so on. This means that when the switch for rate 5 is on, the settings for rate 5 over-rides those of rates 1 through 4.
  • This allows you to have 5 rates on two 3 position switches and changing to a different rate requires at most flipping 2 switches. I fly a mix of IMAC pattern and 3D and so I use 5 rates with each having its own dual rate and expo for elevator, aileron and rudder:
      • Rate 1 (normal) is pattern low rate
      • Rate 2 is pattern high rate
      • Rate 3 is all out 3D
      • Rate 4 is harrier and hover
      • Rate 5 is for knife edge spin.

In my DX6i, I would have to flip 3 switches (elevator, aileron, rudder) to get the combinations I want for each type of flying. This can also be accomplished by using Flight Conditions in the 8FG. However, Flight Conditions are only available if you set up the model as a glider. Furthermore, flight condition is an over-kill for what I wanted for this model. If I were to set up a glider or a scale plane with landing gear, flaps, spoilers, etc. then Flight Condition is the way to go as one flight condition can changing many of those functions at the same time.

  1. To set Dual Rate and Expo, go to the MODEL menu and select DUAL RATE.
  2. You will see AIL as the control surface in the first DUAL RATE screen. Next to AIL are two columns. They refer to the percentage when you move the stick left and right respectively. Set it to a number and see what deflection you get. Adjust those two numbers to get the deflection suggest by your plane’s manufacturer. For example, for my normal low rates for the 3DHS 59” Slick, I ended up with both numbers set to 32.
  3. The next line is EXP for Expo. Again refer to the expo suggested by your plane’s manufacturer. For my Slick, 3DHS suggested and I set both to -30. Note that JR and Spektrum use a positive number for Expo. The graphical representation of the expo curve on the right side of the screen will tell you if you set it correctly.
  4. Repeat for Elevator and Rudder.
  5. The next line contains the value NT. Ignore it for now.
  6. The bottom line of the screen contains the numbers 1 2 3 4 and 5. They represent switches for these rates. Note that there is a “—“ below each number except for 1. This is because rate 1 is always on unless over-ridden by other rates.
  7. To set Dual Rate and Expo #2, select the “—“ entry under the number 2 and press RTN. This will bring you to the switch selection screen. Pick a switch that you like. For me, Dual Rate 2 and 3 have switch SA. Dual Rate 4 and 5 have switch SD. Once you have selected a switch, the ON/OFF entry will be high-lighted/selected for you. Press RTN to go to the ON/OFF screen to set which position is ON and OFF.
  8. If you only have 2 rates, you are done. Otherwise, repeat this for however many rates you want.

For my 5 rates listed above, here are my switch settings:

DR and Expo # Switch SA setting Switch SD setting
Dual Rate and Expo #1 n/a n/a
Dual Rate and Expo #2 OFF, ON, OFF n/a
Dual Rate and Expo #3 OFF, OFF, ON n/a
Dual Rate and Expo #4 n/a ON, OFF, OFF
Dual Rate and Expo #5 n/a OFF, OFF, ON

Once these switch settings are done, go back to the DUAL RATE screen. If you now flip switch SA to the bottom position, there will be an arrow pointing to the number 3 at the bottom of the screen. You can now change the dual rate and expo numbers for elevator, aileron and rudder for rate 3. Repeat for other rates as needed.

Setting Fail Safe

If you are in 7-Channel mode, you can only set fail safe for the throttle channel.

My 8FG Super comes with the R2008SB receiver so I can set fail safe for Elevator, Rudder, Aileron, Aileron2 and Throttle (and more).

  1. Go to the Linkage Menu and Select Fail Safe.
  2. There are 4 columns in this menu. The first describes the control surface. The second describes the fail safe mode for the channel. We will ignore the third column for now. It is for Battery Fail Safe and for aircraft that uses a battery for the receiver. Since I am assuming that most will use a BEC of some sort, Battery Fail Safe is not relevant. Of course, for larger electric aircraft, this might be important. But for now, we will ignore it. The fourth column is the deflection position if we do not want the HOLD mode.

I do not like the HOLD mode and so I use the F/S mode. As an example, to set the Throttle to Fail Safe mode instead of HOLD mode, select the F/S entry for Throttle and set it to F/S. The corresponding POS entry will now show 0%. Move the throttle stick to the bottom and then press RTN for 1 second. The POS entry will now show -100% to indicate that throttle will be off if signal is lost.

Repeat for other channels as needed.

Setting the Count Down/Up Timer

  1. There are four timers in the main screen. ST1 and ST2 are for the selected model. For now, we will only use ST1. From the main screen, select ST1 and press RTN. In the new (ST1) screen, select the timer next to ALARM. Select the minute entry and enter the minutes you want. Do the same for seconds if you so desire. Next, Select the Up/Down MODE. I set mine to DOWN since I like a count-down timer. To simplify things, ignore the other items on the screen for now.
  2. Next, you can set the switch to start the timer. Select the “—-“ next to START and press RTN. This brings you to a screen of all the switches available on the 8FG. You can pick whichever switch you want and then set the ON/OFF position. I like my throttle stick to be the switch and so I selected J3 as my switch. I then select ON/OFF and press RTN. This next screen allows you to set the position of the throttle stick to turn on the timer. I set mine to one click up so my timer only runs when the motor is on. First, select the entry next to ON/OFF and set it to REV (I think this is that Futaba idiosyncrasy with full throttle being stick at bottom). Now move the throttle stick to the position that you want the timer to be turned on. Select SET next to POS and press RTN. To simplify things, ignore the other items on the screen for now.

Keeping Track of How Long 8FG has been On Since the Last Battery Recharge

  1. The system timer at the top of the main screen and next to the transmitter battery voltage shows how much time has elapsed with the transmitter turned on. I use it to tell me, in conjunction with the transmitter battery voltage, when to recharge the transmitter battery. For my transmitter, I have found that it can transmit for more than six hours before the transmitter voltage drops below 7.0 volts. I recharge at that point. The manual suggests that you stop flying and recharge the transmitter battery when the transmitter battery voltage drops below 6.6v.
  2. To reset the system timer, select the System Timer at the top of the main screen. Press RTN for 1 second.

Range Check

  1. Before the first flight of each model on my flying day, I always do a range check.
  2. Turn on the 8FG while pressing the RTN button to get into range check mode.
  3. Select the Range Check option. The low-power count down from 90 seconds will start.
  4. Turn on your power system and walk away from your model in a straight line. The manual suggest 30 to 50 paces. I usually do 40 paces. Make sure that you can move your control surfaces smoothly.
  5. Press RTN to get out of range check mode and back to the main screen.

Locking the Control Buttons/Main Screen While Flying

  1. You do not want your control settings to inadvertently change while you are flying. 8FG provide a lock on the menu/screen. While you are in the main screen, touch S1 for a second. This locks the menu/screen and control buttons. An icon in the form of a key will also appear in the main screen.
  2. To unlock the menu/screen, touch S1 for a second while in the main screen.
  3. Note that if the menu/screen has been locked, it remains locked until you explicitly unlock it. Therefore, turning the transmitter off and on does not unlock a locked main screen.

TIP: Try pushing the RTN button on the home screen, this will turn the timers into large text so they are easier to see. Then lock the control buttons by holding down S1. If you set up your timer with a reset switch (I use SH) you can still reset it without unlocking the thumbwheel.

Congratulations! Your model should be ready for trimming in the air.

Knife Edge Mix

Once your model is trimmed for level and inverted flights, you might want to see how the model flies knife edge (KE) going from left to right and right to left with the canopy facing you. For some models (e.g. my 3DHS 46” Vyper), you can fly KE pretty much hands off with no mixing. For some models, a little Rudder to Elevator and/or Rudder to Aileron mix will help it fly straight.

  1. The Rudder to Elevator mix corrects the tendency of the plane to pitch to either canopy or gear when in knife edge. Note that this pitch is influenced by the CG of the plane and that is one of the reasons to trim the plane for upright and inverted flights to your satisfaction first before trying KE flights. A rudder to elevator mix means that the elevator will move in a certain direction given a rudder deflection. For example, if the plane is pitching to gear on KE going left to right with the canopy facing you, you will want a mix that deflects the elevator up when you put in left rudder for KE, to correct for the tendency to pitch to gear.
  2. Go to the MODEL menu. Go to page two of the menu and select RUD->ELE.
  3. In the new screen, we will only use the first number on the first and bottom lines of the screen. The top line is for KE mix going in one direction and the bottom line is for going in the other direction.

The best way to set the mix is to play with it. I suggest that you set a large number on the first number of the first line and then move your rudder to see which direction your elevator moves. A positive number will move the elevator in one direction and a negative number will move the elevator in the opposite direction. Once you know which direction your elevator moves in responds to a rudder deflection, you can decide if having a mix and how much percentage will help. For most planes, only a small number is needed to be set.

  1. The Rudder to Aileron mix corrects the tendency of the plane to roll left or right when in KE. After you have corrected, if any, the tendency to pitch to gear or canopy, fly KE to see if there is tendency to roll left or right. If there is, you can correct it with the Rudder to Aileron mix.

Go to the MODEL menu. Go to page two of the menu and select RUD->AIL. The rest is similar to the Rudder to Aileron mix.

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