Setting up the InterLink DX in RealFlight 8

Ryan Douglas

Staff member
We've mentioned elsewhere that the new InterLink DX is not fully supported in RF8 but that it should still be usable despite some limitations. Namely, the many 3-position switches will only work as two position switches, and high-speed input from the scroll wheel will be spotty at best.

I've seen some posts lately from people having trouble with the DX in RF8, so I thought a detailed post might help. Here are the steps I took just now running through this for the first time. You may decide to make some different choices than I did, and that's okay, but hopefully by the end of this post you will have a understanding to inform those decisions.

  1. Connect your InterLink DX and start RealFlight 8.
  2. From the Simulation menu choose Select Controller...
  3. If you have more than one controller connected, click to select the InterLink DX.
  4. Start at the top, in the Controller Setup section.
  5. Click the Edit button to begin customizing the radio profile. (It should have defaulted to the Gamepad profile, but in this case it doesn't really matter because we're going to redo everything.)
  6. For Channel 1, click the input button (it probably says "Dial" currently) and move your aileron stick. Direction doesn't matter. Just be careful not to bump any other inputs, because you don't want it to "hear" the wrong one.
  7. For Channel 2, click the input button (it probably says "Z Axis" currently) and move your elevator stick. The same notes from Ch1 above apply here and to all subsequent channel mapping steps.
    Also, uncheck the Reverse option.
  8. For Channel 3, click the input button and move your throttle stick.
    Also, uncheck the Reverse option.
  9. For Channel 4, click the input button and move your rudder stick.
  10. For Channel 5, click the input button and move your dual rates switch. I chose to use Switch C.
    Important note 1: If you choose a three-position switch like I did, you should first move it to either the center position or the up/down position you wish to use, then click the input button and move it in the desired direction. In my case, I want to use the up position for high rates and the middle position for low, so I moved the switch into one of those two positions before assigning the input. If it starts out in the down position, then you will end up mapping the center and down positions to the new channel instead of center and up. But not to worry if that happens; simply adjust the switch position as needed and click the input button again to remap it.
    Important note 2: After mapping the input to your satisfaction, expand the dropdown control and change Toggle to Proportional.
  11. For Channel 6, click the input button and move your flaps switch. I chose Switch D. See the Important Notes for Ch5 above. They apply to all subsequent numbered channel mappings.
  12. For Channel 7, click the input button and move your smoke switch. I chose Switch F.
  13. For Channel 8, click the input button and move your mode switch. I chose Switch B.
  14. For Channel 9, click the input button and move the left slider on the rear of the controller.
  15. For Channel 10, click the input button and move the right slider on the rear of the controller.
  16. I chose not to map channels 11 & 12 at this time because no stock models use them as inputs.
  17. Scroll down to the Trims section.
  18. For Roll Increase, click the input button and move the aileron trim to the right.
  19. For Roll Decrease, click the input button and move the aileron trim to the left.
  20. For Pitch Increase, click the input button and move the elevator trim up.
  21. For Pitch Decrease, click the input button and move the elevator trim down.
  22. For Throttle Increase, click the input button and move the throttle trim up.
  23. For Throttle Decrease, click the input button and move the throttle trim down.
  24. For Yaw Increase, click the input button and move the yaw trim to the right.
  25. For Yaw Decrease, click the input button and move the yaw trim to the left.
  26. Scroll down to the User Interface section.
  27. For Reset, click the input button and press your Reset button.
  28. For Select, click the input button and depress your scroll wheel. Be careful not to roll it left or right in the process. If that happens, simply click the input button again and remap it.
  29. For Cancel, click the input button and press your Cancel button.
  30. For Up, click the input button and roll your scroll wheel to the left. Note that it may take a bit of rolling before it is detected.
  31. For Down, click the input button and roll your scroll wheel to the right. As above, note that it may take a bit of rolling before it is detected.
  32. Look back up through the list of all the controls you have mapped. Other than anything you deliberately left unmapped, make sure no channels show Unassigned for their input. That can happen if you accidentally bump an already-mapped control during a later mapping step for a different channel. When that happens, it unmaps it from the originally assigned channel. The fix is simply to remap it in the desired original location.
  33. Click Save As...
  34. Enter InterLink DX as your new radio profile name and click OK.
  35. Click Close.
  36. Back at the Select Controller dialog, click Calibrate, and follow the instructions. For this type of controller you only need to move the two sticks and the two rear sliders to their extents.
  37. When you click to finish calibration you will receive a warning message about only 6 of the 8 axes being calibrated. That is normal for this particular situation. Click Yes to proceed.
When complete my radio profile looks like the images below.

The three-position switch limitation can really be felt with certain vehicle setups, such as helis with three flight modes (normal, idle up 1, & idle up 2), or airplanes with three AS3X or similar flight modes, or drones with three advanced flight modes, or models like the P-51 Mustang where both smoke and the actuating canopy are mapped to channel 8. There is no getting around that drawback on the hardware side, but remember that the Virtual Channels offer a way to supplement the available controller inputs and provide that finer level of control.



Active member
This would be for Mode 2. To apply this as Mode 1, just swap the parts that indicate they are for elevator and throttle. Remember that the controls are just the controls. The words don't define the actions, just what data stream the controls flow down.

Mode 2 Sticks, Y-Axis/Toward and Away:
Right: Elevator
Left: Throttle

Mode 1 Sticks, Y-Axis/Toward and Away:
Right: Throttle
Left: Elevator

The Select Controller...Edit dialog in RF is where you take what is presented by Windows and tell RF where you want it to go. Most, if not all, current 9/9.5 models will expect the input to be Mode 2 Channel Mapping. Rather than having to edit every plane model individually, the Select Controller...Edit dialog will let you USE the sticks in Mode 1 (Elevator, Throttle), but present the data to the Mode 2 (Throttle, Elevator) mapping expected by all the models.

The assignment process in the Select Controller...Edit dialog is just like it is in the DX6 you fly with. It's auto sensing. You don't have to think beyond seeing "Elevator" as the Function expected by RF in the first column, then clicking the Input box in the last column and moving the left stick up or down like you would at the field. RF will sense the input that changed and connect your left stick to Channel 2 - Elevator. To set the Throttle up, do the same thing. Click the Input box in the last column beside Channel 3 - Throttle, and move your right stick up or down. Click the Save As button and give it a name like InterLink DX Mode 1. As long as that is the active controller, you can operate your hands in Mode 1 and RF will handle the rest!

Let me know if you still have questions. As you know, I'm happy to help and determined to get new folks to the point where they understand as much as they need or want to to accomplish their goals in RF, whatever those may be!



New member
Thanks for the help. Few questions,
1. I am using RF9.5 , this should be the same?
2. Is the Throttle & pitch mixed? and where? When you raise the Throttle stick, Pitch should go up as well?
3. Is this set up have throttle hold ? and where
4. Same as above for Throttle up?


Active member
  1. Yes, it should be the same in every version of RF including 9.5.
  2. This depends on the particular heli model selected and whether or not throttle hold and throttle up are active.
  3. All of the 3D heli's will have a Throttle Hold switch. Usually TH is mapped to the top right switch. (Switch G on the InterLink DX, Input Channel 9)
  4. All of the 3D heli's will have an Idle Up switch. (Switch B on the InterLink DX, Input Channel 8)
As a refresher:
  • Input Channels are fed through the Software Radio if enabled, or straight to the Electronics of the model if the Software Radio is disabled. Input Channels correspond to the "Function" column in the Select Controller... dialog.
  • Throttle Hold is basically a safety function to hold the throttle setting at zero and ignore the throttle stick position. Get in the habit of putting your throttle stick at the lower stop and engaging the Throttle Hold before every flight, before hitting the reset button, and any time the heli is on the ground. RC heli's have severed fingers, mangled hands, arms, and faces, and even killed. Always use the Throttle Hold, even in the sim, even if your radio is off, there is no battery in your radio or heli, and nobody is anywhere near the heli, real or virtual.
  • Idle Up is a work around for the need to have 5 axis control in a heli. Helis use 3 channels for roll, pitch, and yaw, just like planes. They also use a 4th channel for throttle, just like planes. Then you hit the need for control of the collective, and you are past the 4-axes limit that the control sticks can produce. Idle Up sends a fixed value for throttle, then uses the throttle stick axis for controlling the collective. There may be a low and high setting available for Idle Up. They are referred to as Idle Up Low/High or Idle Up 1/2. Idle Up 1 is suitable for most 3D flying. Idle Up 2 raises the RPM even higher to provide maximum power for maneuvers that use extreme collective and/or rapid collective changes between positive and negative lift. If you hear the RPM dropping significantly as you perform 3D maneuvers, switch up to Idle Up 2 if the model has two Idle Ups.
  • Channel mixing in RF can occur in the physical radio transmitter, the Software Radio for the model, or the Electronics for the model. If the InterLink is used, then mixing can only occur in the Software Radio or Electronics. Most of the time, you will not need to fiddle with the mixing for the model. Most are tuned to provide maximum control and controllability by the person who tuned the Physics Model for the heli.

RC Heli Flight Modes: Generally speaking, RC heli's operate in two basic modes: Normal or Idle Up.
  • Normal mode will use the throttle data from your controller to control the engine/motor RPMs and may or may not also change the Collective, depending on the specific model. Typically in this mode, you will only have the ability to change the amount of upward force generated by the rotors. Think of the collective as having values from -100 to 100, like RF uses them. Negative values will produce negative lift, literally pushing the rotor head toward the heli with maximum force. Zero will produce no positive or negative lift. 100 pulls the rotor head away from the heli with maximum force. Normal mode will mostly operate only in the positive 0 to 100 range. This is great for precision upright flying, like you would want with the Sikorsky Skycrane, but does not permit inverted flight.

    Be careful in this mode with 3D heli's, though. Some may actually apply negative collective, and therefore downward thrust, at zero throttle as a way to ensure that you have the throttle value high enough to successfully get off the ground before causing the rotor blades to actually produce lift. Effectively, this means that the only time your throttle stick should be at its bottom stop is when the heli is on the ground. Then it should ALWAYS be on its bottom stop. Don't cut the throttle all the way down while you are in the air. Rather, get in the habit of pulling the stick down to 15-25% and adjust as needed from there.

  • Throttle Up mode basically does exactly what it says. When it is active, the throttle will be set to some particular fairly high value and the control that was the throttle will be used to operate the collective servo. With this mode, you will not be able to adjust the throttle, but you will usually have full range control of the collective. That means that the collective now operates from -100 to 100, with no thrust at 0. Since you now have access to negative collective, you can use negative lift to fly inverted and do all sorts of 3D stunts like crash nearly instantly, fly inverted into trees, dent cars, and otherwise do massive damage to your virtual wallet! Yea!!
Remember that once the signals hit RF9.5, they will get sorted into "Input Channels." If the Software Radio is enabled in the Select Controller... dialog, the signals will then get interpreted by RF's Software Radio. You can view and change the settings in the vehicle editor on the Radio Tab and in the Electronics Tab if you want to fiddle with the throttle settings for Idle Up, or otherwise play with channel mixing, gyros, etc.

Hope it makes better sense now, but questions are always welcome!


New member
Thanks, I got it going now. What will be the best Heli to get trained. I fly Drones and Planes in real models, I want get trained in Heli's


Active member
Start with one that has a flybar or coaxial rotors. Those will be the easiest to control. I think that there is one that has the training cross mounted to the skids. That's a pair of crossed sticks that have balls on each end. Most new pilots think that the balls act as bumpers, and they do, but the real purpose is to put more mass that is widely spread from the rotor axis. The extra mass and it’s location acts too slow the natural movements if the heli and make them more easy to see.

Sorry I don't have the names, but I'm away from my PC. Don't forget RealFlight has a pretty good training system that's available in the menu. If I recall correctly, it even extends through some 3d stuff.