DX7s and flaps for the Bixler 2

[Sammy]

Hi,

I've been trying to figure out how to setup mixing on my Spektrum DX7s for the flaps on the HK Bixler 2, but I can't get it to work. Here's my setup:

• Spektrum DX7s TX
• OrangeRX R615 RX
  • Left Aileron & Right Aileron via Y-harness on AIL channel
  • Right Flap on GEAR
  • Left Flap on AUX1

I can't use a Y harness on the flaps, cause one of the servos' has to be reversed. Currently the L-FLAP works fine, but the R-FLAP moves along with the R-AIL, which is obviously not a good thing

I've been going through the DX7s manual a dozen times already, but it's not really helpful. All it tells me is to set up mixing, AUX1 should be set as master and GEAR as slave if I got it right, but this is exactly where I get stuck: when I select AUX1 as master, GEAR is not a possible slave and vice versa. Obviously I'm doing something wrong, but I can't figure out what? I have googled this and found a nice step-by-step guide for the DX7 (http://www.rcuniverse.com/forum/rc-...-dx7-flap-programming-4-servo-wing-print.html), but its menu structure seems to be different from the DX7s: I don't have Input Select, Switch Select is the one that comes closest I guess, but I can't change anything there, I only have Inhibit as an option...

Help guys, I'm going insane!

 

[xuzme720]

I think you've run across one of the reasons I don't fly Spektrum. Programming is not as flexible as it sometimes needs to be. From what I gather, the aux channels can only be slaved to primaries in the mixes so trying to mix flaps when it's on 2 separate aux channels(gear,aux1), is an exercise in frustration. You might just have to get a reverser. https://www.hobbyking.com/hobbyking...o_Signal_Reverser.html?strSearch=servo revers

There may be a way in the radio, but if there is, I haven't come across it...

 

[Craftydan]

Naw. totally doable if you've got the channels in your RX -- I've got a 4 servo wing with full crow mixing programmed into my DX7S for my Calypso glider, for a full 7 channel power glider.

Stand by . .. Gotta go get my TX to write down the mixes . . .

 

[xuzme720]

I guess I have bad info. Good to know! At least you don't have to buy anything to make it work!

 

[Craftydan]

Ok, a little long and drawn out (my most complicated mix . . . and SOME CLAIMED IT COULD NOT BE DONE!!!! I'LL SHOW THEM!!! Muhahahahahaha!) . . . ahem, but it works.


First things first, my design:

I'm setting this up to be a power glider, but no reason it wouldn't work for a Bixler. the servos for my wing are installed outer opposing inner matching, but that can be adjusted in the servo menu on the radio. Throws on all four are set for center neutral. In the power mode, The throttle runs the motor, and the flaps and ailerons are fully responsive(4 servo ailerons, with the inner 2 acting like flaperons according to the flap settings). In glide mode, the motor is disabled, the ailerons are still responsive, but revert to crow with the strength of the crow is set according to the throttle (0 throttle clean with full ailerons, full throttle full crow breaking).

If you want to forgo the glide mode, and simply have full length ailerons with flaps, that's doable -- Skip mix#2 and #3. I'd still recommend the throttle cut . . . but I always do -- that's a safety feature.

*** one note about Spektrum mixing oddities: if the radio splits a surface between two channels (like LAL/RAL or LFL/RFL) the Mixing to the right adds the mix in normal amount to both, while the Left surface adds the mix in opposition to both . . . which is really weird for ailerons when they're normally in opposition. What I've done works . . . but keep this in mind when you decide to go off script.


In the model setup:
* For wing type: Set the wing: 2ail,2flap, Tail: normal

In the running menu:
* Servo: Trim the plane as best as you can, then set the throw, reverse and subtrim (for the mixes below, trim the wing servos to neutral with ailerons opposing and flaps synced)
* D/R and Exop: set to taste, but be careful which switch you assign them to . . . we may need one in a moment.
* Differential: Inhibit (you're free to set this up if you care. the calypso doesn't seem to need it).
* Throttle cut: Pos: 0%, Sw: Mix 1(right back switch forward) -- this cuts the motor in glide mode, and also acts as a safety.
* Flap System: Norm: 1%, 0% Mid:-40%,10% Land:-80%, 20% Speed:2.0s Sw: Flap (This sets how far the inner surfaces move downward, and any elevator up-trim in response. Play with the flap values until the servos move as much as you like them to, then adjust the elevator so the nose stays level as you advance the flaps. If one flap moves opposed, reverse it in the servo menu above)
* Mixing:
-- Elev>Flap: Sw: Inh
-- AIL>RUD: Sw: Inh
-- Mix 1: Ail > LFL Rate: -100, -100 Offset: 0% Trim: Act Sw: On (this causes the *both* flaps to follow the aileron input)

-- Mix 2: Thr > LAL Rate: 75,75 Offset: -100 Trim: Act Sw: Mix1 ( this causes the *both* aileron servo to move upward from center as the throttle advances from 0 to full, when the throttle is cut by the mix switch. Skip if you don't want crow breaking)
-- Mix 3: Thr > RFL Rate: -50,-50 Offset: -100 Trim: ACT Sw: Mix1 ( this causes the *both* Flap servos to move downward from center as the throttle advances from 0 to full, when the throttle is cut by the mix switch. Skip if you don't want crow breaking)

-- Mix 4-6: Sw: Inh

Whew!! that was a lot of work, but she flies like I like She powers up to the top, I throttle back then flip the cut. kick the flaps up or down depending on the air shes in, and pull up the throttle to open the crow breaks when I want her to hover in the wind.

Crow could also be set to control the knob on the back by changing Mix 2&3 to KNB>XXX, and it can also be moved to another switch, but not sure why you'd want crow while the motor was running.

 

[Craftydan]

hmmm . . . Sammy, looks like I've answered my question and not yours . . .

For a 615, set the config to 1 Ail, 1 flap, in the wing setup, set the gear switch to INH, then in the normal menu, setup the flap system, then create a mix for FLP >GER, Rate: 100,100 Trim: ACT SW:On, and it should start following the other flap, instead of following the aileron. if it opposes the flap, reverse it in the menu.

As far as mixes, you could add on Mix 1 from above, and the inner flaps will act like flaperons, giving you more lift when down, and more roll when up.

Edit: Mixing can be . . . complicated. the 7S likes to assign LAL to channel 7, which the 615 doesn't have the above had been corrected and should work.

 

[xuzme720]

I'm guessing my info was a holdover from the DX5 or 6 then. I was told that you couldn't slave aux to aux.

Made my day, Dan, as I hadn't learned anything new today until now!

 

[Craftydan]

I'm guessing my info was a holdover from the DX5 or 6 then. I was told that you couldn't slave aux to aux.

Made my day, Dan, as I hadn't learned anything new today until now!

Wewh! just under the wire too

(BTW, the 6i and better can slave a channel to the same channel, allowing you to magnify, cancel, or reverse it's response on the flip of a switch . . . mostly useless . . . until you need it)

 

[OrangutangSurfer]

I can't use a Y harness on the flaps, cause one of the servos' has to be reversed. Currently the L-FLAP works fine, but the R-FLAP moves along with the R-AIL, which is obviously not a good thing ��

can't you reverse the single servo that plugs in to the Y harness? I know if you switch in on the receiver it reverses both but you should be able to just switch the one that plugs in to the Y and that should do it.

(or did I miss something)

If your talking about flaperons - I haven't made it that far yet.

-Jes

 

[Sammy]

For a 615, set the config to 1 Ail, 1 flap, in the wing setup, set the gear switch to INH, then in the normal menu, setup the flap system, then create a mix for FLP >GER, Rate: 100,100 Trim: ACT SW:On, and it should start following the other flap, instead of following the aileron. if it opposes the flap, reverse it in the menu.

Craftydan, you are a genius, thank you so much!

 

[Craftydan]

Craftydan, you are a genius, thank you so much!

Nope . . . just a frustrated but stubborn Spektrum user

Glad I could help!

They really are nice radios, but the mix system is . . . complicated -- a lot of power, but not very friendly.

 

[Tugpilot]

Hi, noticed your spektrum thread and hope you could help me out, DX7S Ar 8000 RX, flaps plugged into gear channel, what i would like to achieve is the landing lights which have a servo to each one, they drop down from inside the wing and turn on with a microswitch, tried mixing with aux 2, tried several combinations but struggling to avhieve my goal, what i would really like is to have landing lights so that when flap switch is used the landing lights come down and switch on, if this can be done this way it would be superb as flaps are on a timer to slow it all down?
Many Thanks
Derek

 

[Craftydan]

Hey Derik, Welcome to the forum!

I think I've got a picture of what you want to do mechanically, but let's clear some details up. I'm assuming you've got your standard flight controls plugged in to the first 4 channels. You've just said your flaps are in #5 (I presume it's so you can take advantage of the slower deployment the "flap mixer" provides to sequence your landing lights) . . . then you plug in the landing lights into #7. Any reason you didn't want them on #6?

What control are you using to actuate the flaps? Landing lights? Anything else plugged in that might be getting in the way?

I've got some suspicions about what's giving you troubles (and you might not be able to get all the way to what you want), but I'd need a few more details before I can be certain.

 

[Tugpilot]

Thanks for your reply,
yes first four are std. controls, wing set up as two ailerons and one flap(y lead) plugged into gear channel, l.light servos (y Lead)plugged into aux 2, if we cannot get slow along with flaps no worries, anything is better than nothing?
I am using the three position switch, 1st for takeoff flap, second for full landing flap.
Cheers

 

[Tugpilot]

Flaps

Thanks for your reply,
Yes first four std, wing set as two ailerons one flap(y lead),plugged into gear channel, Landing Lights(Y Lead) plugged into Aux. 2.
Three position switch, position one for takeoff flap and pos. 2 full landing flap.

Anything is better than nothing?

 

[Tugpilot]

Hi, Did we have any result for my dilemma with lights and flaps?
Cheers

 

[Craftydan]

Sorry Derik, Haven't had a chance to pull out my DX7s to test . . . but . . .

First, everything I've seen and done, the flaps connect into Aux1 (#6), and you have to select a wingtype with flaps to activate the flaps option in the main menu. Enable and fill out positions in the flap menu that should make that switch start to work. If you attach your landing lights to the gear channel (#5) you should then have those set up to the Gear switch (left-top-back), then just set the throws and direction for the gear channel to suit the up and down positions. That'll get you to "working", but the lights will simply pop out. you can add in a servo slower, landing gear sequencer or a programmable digital servo to slow down the command but that's the best this will get.

I know you wanted to steal the servo slowing from the flap mixer, but once you turn on the flap option, that three position switch is tied to the flap mixing -- no way to reassign it. To get three position flaps and put the lights on the three position switch you'll have to move the flap servos to another channel and control that either by the knob or two other switches mixed to add up to the positions you want . . . Unless . . .

What I haven't had the time to try is to see if you can mix another channel to the FLP with flaps enabled and see if that smoothly deploys -- I'm not sure it does, but even if it did your landing lights would be tied to the flaps being down in the landing position -- you could not deploy the lights without fully deploying the flaps . . . and it might get tricky getting the servo centering and throws right between the flap and lights so when you kick the flap switch down the lights don't jump to a midpoint then slowly deploy the rest of the way.

BTW, if you're ever uncertain as to what the radio has assigned to what for the selected "wingtype", pop open the monitor page in the menu and the assignments from top to bottom, 1-7 should be listed with a three letter abbreviation.

 

[Tugpilot]

Much obliged to you for your input, i will go play and see what can be done, sometimes another pair of eyes highlights something that has been seen but not understood.
Regards
Derek

 

[Tugpilot]

DX 7s

Hi Dan,
Been looking at the DX7s programing diss=cussion, with a seven channel RX can we get crow and up aileron and have the flap and aileron configured for thermal and speed trim, after all this can we still use throttle cut?

This is to programme a Blade XXLE full house.

Our previous discussion about flaps and landing lights was resolved but without the timer.

Happy landings
Derek

 

[Craftydan]

Absolutely.

Throttle cut is active all on it's own and overrides all mixes to the throttle. In my crow mix I've even assigned the cut to the same switch I activate the crow with -- no sense running the motor with the airbrakes on. I can then use the throttle stick to proportionally deploy the crow while the motor is cut.