(DX8i Config file: HERE)
Plug RIGHT AILERON into AIL port on receiver
Plug LEFT AILERON into AUX1 port on receiver
Plug BOTH FLAPS into Y-CABLE then plug Y-CABLE into the FLAPS port on receiver
I saw your posting about using Spektrum's RP file, which is a good idea. It gets you started with easier to use programming (less complex to remember). I based my setup on their RP file, plus bits lifted from their generic full-house glider file along with my own ideas.
First off, basic safety. Please remove your prop blades before you test this one. It has many features. I've used most of the DX8's switches, all of its mixes and in general pushed it. It's more confusing to operate than their setup. Practice using it on the ground, before flying. Master the F-mode, Aux2 and Mix switch functions, before flying.
Before powering up the DX8 (after initial setup) place all switches in their proper position. The programming will attempt to warn you about what it can. However, the DX8 offers a very limited selection of power up switch position alarms. Pre-flight the DX8 as well as the RP itself.
All switches, except the Aux2 three way switch on the right center, should be fully back and the throttle down. Power up the DX8, flip the right rear Mix switch on (it has multiple functions, but the most important at this point is throttle cut). Connect the RP's ESC to your flight pack. The RP's ESC should beep and the flaps extend almost fully. This looks odd, but it's normal for this setup.
Working across the top row of switches:
Ele D/R controls all three axis D/R with one switch. Fully up is 100% throws, no Expo. Moving the switch down selects 100% with soft expo, down again reduces throws and adds more expo. I fly using the upper position. When guest pilots test fly my RP I offer it to them in the middle position.
The flap switch should be up. Moving it down selects one of two levels of preset flaps with elevator comp. You must fine tune these for your RP's flap linkage configuration. I'm using the second to inner most flap horn holes, providing more than out of the box flap deflection. Moving to the inner most hole would give you greater flap deflection. Both positions are fairly mild flap deflections. Serious flap deflection combines these presets with flaps on the stick.
The left trimmer switch next to the flap switch offers flap trim. This trim setting is an across the board setting, like the Ele D/R switch. The only way to center it is listen for the "on center" chirp tone. I rarely use this switch.
The right trimmer does nothing. The only unused switch.
The Aux2 switch works like RP setup you downloaded from Spektrum's site. Center is normal on this one, it's the only switch that isn't normally fully back/up. Up is reflex, center is normal/cruise and down is camber. Aux2 functions only in F-mode 1 and 2, not in F-mode 0 to avoid leaving it on during launch.
Aileron D/R controls snap flaps. Fully up is off, either of the other two position is on. Snap flaps are fun on the slope, but watch out they almost work too well. Your RP's wing will flex under load.
The rudder D/R controls aileron->rudder mixing. Fully back is off, either of the other two positions is on. I very rarely use this switch. However, it seems to help guest pilots.
On the left side in the same place as the rudder D/R is the F-mode switch. This one is more complex and very important. It selects one of three flight modes. Down is launch mode, center is normal, up is a special "in flight tuning mode" used to fine tune wing camber in thermals.
The F-mode switch changes throttle curves (also flap/crow mix input curves), enables and disables various mixes, controls aileron diff settings and offers a completely independent set of trims in each position.
The F-mode and the Aux2 switches change the RP's flight characteristics. Spend time to fully understand both of them, before flying.
In launch mode (F-mode 0) aileron diff prevents lowering an aileron, this helps avoid dropping a wing during climbs. Launch mode trims help with power on nose pitch up. Various mixes are disabled to simplify launching. I couldn't disable crow in this flight mode, the DX8 has limitations.
In normal mode (F-mode 1) aileron diff is as stock, plus its trims provide your normal flight trim settings. Most mixes and features are enabled in F-mode 1. You will spend most of your time in this mode.
In-flight tuning mode (F-mode 2) offers it all. The Aux3 knob continuously varies flap deflection, down and up. There's an another independent set of trims and aileron diff settings.
You can create camber/reflex like wing profiles without using the Aux2 switch, or better yet, combine the Aux2 switch with the Aux3 knob for serious tuning. Fine tune F-mode 2 aileron diff for best tight thermal turns too. You can spend hours fine tuning your camber, reflex and aileron diff settings using this F-mode.
Flipping between F-mode 1 and F-mode 2 gives you an A vs B method of deciding if the preset camber/reflex deflection is really better or worse than your fine tuned setting. Use this to determine your RP's overall preset Aux2 camber/reflex deflections.
Remember, all three F-modes have dedicated independent trim sets. This allows launch trims, normal trims and a set for tuning, very handy for slow camber flight elevator comp.
The gear switch controls crow, back is off, forward is on. Unlike Spektrum's setup, it tracks with flaps on the stick. It's easy to leave crow enabled after landing during the next launch. The DX8 doesn't provide a way to disable it based on the F-mode switch position.
The mix switch controls both the throttle cut (safety) and flaps on the stick. In the back position the motor is enabled, flaps on the stick are disabled. The preset flap positions still work, only flaps on the stick are disabled. Flip it forward at the top of your climb to disable the motor and start gliding. While gliding keep throttle above half to avoid extending the flaps.
Flaps/crow on the stick, above half stick is a dead zone to provide a way to abort a landing approach and room to move the stick (for rudder) without moving the flaps/crow. I don't like flying with the throttle stick jammed fully up or down, it's uncomfortable and stresses the stick. Sweeping the stick down below half slowly lowers the flaps (and if enabled crow).
My typical landing uses only the preset positions, except maybe a touch of stick on final. Spot landings use presets, enable crow and stick. I find the presets valuable, because they provide a dependable glide slope that's quick and easy to use. Using the stick properly requires practice and increases pilot load.
To abort an approach, assuming you used flap presets, flip the mix switch back while quickly advancing throttle. Most flap deflection will instantly retract, and the motor will start. At this point, it's just like a full-scale abort. Keep the nose down to build airspeed, then climb out while slowly cleaning up the wing.
The preset flaps provide low airspeed lift supporting the RP, allowing most flap drag to be removed without stalling. Once the RP is flying level and gaining airspeed flip in to F-mode 0 (launch) to optimize for climb out (trim and aileron diff), then slowly raise the preset flaps one position at a time.
A typical launch sequence. Pre-flight the DX8 switch settings. Double check the crow switch! It's easy to leave that on after your last spot landing. Make sure you're in F-mode 0. I hold the RP up and wiggle the controls, then flip the mix switch off. Flaps should retract when you move the mix switch. Advance to about half to 2/3 throttle and listen for that RP loose nose parts noise, it should sound smooth. Then throw the RP and advance throttle after verifying that the RP is flying correctly.
Spend the time to fine tune the elevator comp in the flap menu. Each preset flap position should provide a nice controlled hands off glide slope. Once you have that worked out use the monitor screen to match the elevator/flap positions of the presets to the flaps on the stick without the presets in use. This way, you can use either presets alone, presets with stick or stick alone and have elevator comp.
In the case of preset with stick the elevator comps add up to too much. Don't slam on full stick on top of the presets until you learn to feather the elevator a bit to counter act the excess elevator comp. It's easy to pull up a bit as you lower the stick.
Full stick with presets and crow will bring the RP down on a very steep glide slope. With practice, it's possible to clear an obstruction and land in a small area. It's all in the flair in the last few feet, counter excess elevator comp while max flaps and crow burn off energy just before it contacts the earth.
Be careful when flipping the mix switch off (make sure the throttle stick is fully down, before flipping that switch).
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There's a motor run-time timer (tone+vib) set for 5:00. The timer starts and stops with the motor. A nice feature of the DX8. One minute before the motor run timer expires a "One minute warning" tone occurs.
Glance at your watch before launching and at the one minute warning. It's possible to estimate battery charge state. It's no fuel gauge, but better than blind guessing.
A brand-new stock BNF RP (prop/motor/ESC/battery) has five minutes of motor run, used as 30 second climbs. ESC/RX/servos consume a minute's worth of energy per hour gliding.
On flat days and landing practice the timer is about all you need. Long flights expose the load of the other electronics. One hour gliding after a single 30 second climb is 3:30 remaining, not 4:30 as shown. On good days and sloping, it's possible to empty the pack without a peep from that timer.
Packs decay with use and age, yielding less motor run time. Changing batteries at the one minute warning helps prevent deep discharging worn packs. Running until the LVC starts punishes your packs.
I leave the motor enabled for the least amount of time possible, only during launch climb out. Once at the top, flip the mix switch and start gliding. With a bit of practice you can find and flip that switch in a split second if you need to abort a landing approach. Heli pilots should find using that switch second nature.
After using the mix switch at the end of your climb, let the RP settle in to a stable glide and then flip the F-mode switch to F-mode 1 enabling most of the radio/RP features. There's no rush, but don't put it off for too long, because it's easy to forget.
Flying in F-mode 0 works, you just don't have full roll control authority (due to aileron diff) and the Aux2 (reflex,cruise,camber) switch is disabled.
At first, I had issues with crow, diff and aileron travel. My answer was to move the linkages on the aileron horns to the inner hole (max aileron travel). With extra aileron travel available there's room for crow while still providing enough additional travel for roll control.
It's better to have less crow deflection than to have less than full roll control. Extreme upward aileron movement for crow doesn't seem to be required for good glide slope control.
In my setup, F-mode 1 is your best choice for landings, more so when using crow. The other two F-modes are really only for specialized use (climb out and working a tight thermal).
The problem with the DX8's non-configurable inactivity timer is that it has a five minute inactivity time-out, used to be 10 minutes until the last firmware update. When it triggers it goes full melt down psycho crazy, it's extremely annoying.
It beeps constantly, as if that wasn't bad enough it also continuously pulses the vibration alert motor too. That poor little motor becomes very hot within a couple of minutes, consumes more energy than the rest of the radio rapidly depleting the battery, and the vibration walks your DX8 off the edge of the surface it's resting on.
I've grown to hate that damn inactivity timer. Spektrum's answer is as DX8 owners we haven't paid enough to earn the privilege to configure the inactivity timer. I didn't want that damn thing to begin with. I'm ready to disconnect that vibration motor.
If it was set to something reasonable, say 30 minutes, beeped a couple times per minute (like a smoke alarm low on battery) and didn't vibrate I wouldn't complain.
Question for the Radian Pro owners using a DX8. I picked mine up yesterday and got it all together and downloaded the setup for Spektrum for my DX8.
Problem I'm, having is the Crow, Reflex & Camber functions. The Flap function, works perfect, but when I try any of the other setups, say the crow for example, the right aileron goes up, flap goes down, but the left aileron is going down instead of up? Same goes with the other functions, they are going opposite of what they should be (ailerons)
I thought downloading the setup I could just fine tune to my liking, any thoughts on how to correct?
Sounds like you still have the aileron Y-Cord connected. You need to remove the Y-Cord and plug the ailerons into two separate channels.
Yep sounds about right...Right Ail in AIL Port.
Left Ail in the AUX1 port...Enable Duel Ail in the wing type mix.
Use Aux2 position 0 for reflex, position 1 for "level" and position 2 for camber. Basically, the Aux2 switch position matches the movement of the trailing edges of the wing control surfaces. Easy to remember and verify during pre-flight checks.
Once you're used to that set-up, you might want to try other options, such as flaps and crow on the throttle stick and in-flight fine tuning of the flap deflection using the Aux3 knob. The knob set-up is easy, but programming and using flap/crow on the stick is more complex and confusing.
Spend the time required to properly set-up your Flap>Elev settings in the flap menu. You want to add more "down" Elev with increasing downward deflection of the flaps. If you don't, your RP will nose up hard and stall when you use flaps. Once you have your flaps set-up properly it almost lands itself, just keep the wings level and steer in to the wind using the rudder. If at all possible, avoid using Elev until you flare a couple inches off the ground. Even if you don't flare, it will land fine.
It's better to have a little too much down Ele in your flap settings than too little, because a stall a few feet off the ground often ends in a crash. It's much easier to pull back a bit on the stick than it is to add just enough down Ele to recover airspeed to begin flying again, without using so much you dive in to the ground. You wont have much time or room to figure out how much is too much or too little.
If you have a bit too much down Ele in your flap settings it will usually just land a bit sooner and harder than you expected. The RP is flexible and survives diving a bit too sharply better than it does a hard stall followed by a nose down vertical impact. An over steep landing makes a bit of noise, a stall induced crash breaks the nose clean off.
It's easy to reattach the nose using white gorilla glue.
Take it really easy on the dives too. The RP is not a high-speed craft. It can get really out of hand in a steep dive and the extra loads placed on the wings causes them to flex. Inside loops are fine, but don't expect it to roll and pull outside loops like a war bird or pattern plane.
I've found a CG at 74mm works better than 70mm. Start at 70mm and slowly move the CG back after you get your settings dialled in.
Unless you only fly on short well-trimmed grass consider adding servo covers. The Ail servos strip easily, and replacing one of them is as expensive as adding servo covers. I had to strip a servo to learn that lesson.
The stock BNF battery (when brand new) is good for about ten 30 second runs of the motor at full throttle. Using less than full throttle is usually not worth it, except when throwing it during a launch. I launch using 2/3 to 3/4 throttle depending on the wind, then quickly advance to full throttle to begin climbing. After about 30 seconds turn the motor off and start gliding, it's a far better glider than it is a power plane.