Spektrum DX8, 6 flights mode with one singel channel, by FM and Gear Switch

If you want 6 flights mode with Gear and Flightmode 1,2 switch with only using one channel (CH5) the following can be done with dx8 and maybe DX7:

Go to servo set up, set Gear to 85% and 65% in travel

Go to mixing:

Select Mix 1

Select GER >GER Set rate: to -31% and -23% ( these are the rates for gear sw pos '0' and Flight mode 1 and gear sw pos '1' and Flight mode 1)

Leave Offset at 0 %

leave Trim: set to Inh.

Set Sw to FM 1


Go to Mix 2

Select GER >GER Set rate: to -100% and -76% ( these are the rates for gear sw pos '0' and Flight mode 2 and gear sw pos '1' and Flight mode 2)

Leave Offset at 0 %

leave Trim: set to Inh.

Set Sw to FM 2

Then to check go into mission planner(APM setup), connect the arducopter and the radio then choose modes in the apm setup

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This is an awesome post, thanks.  I have used up all of my mixes.  Is there a way to do it with only one mix?  That is all I have left.

Unfortunately this doesn't work with the DX7s, there's no FM 2 option in the Sw field.  Is FM a 3-way on a DX8?

On a DX7s, I'll need to use the Flap (3-way) and Gear (2-way) switches.

Yes the FM switch on the DX8 is a 3 position switch... I have never played with a DX7 sorry.

Thanks for the Post.... question: Does my DX8 have to be set up in HELI mode or could it be in AIRPLANE mode ? My DX8 is in airplane mode and APM planner is not recognizing the changes.. Do I have to assign ch 5? How do I do this? Which is CH 5?

Maybe I'm having problems mixing (setting the master and slave)... 

thnks again

Ok fixed the problem.. I forgot to change the servo lead cables from AUX 2 and AUX 1 and connect them to GEAR on my receiver ... :)

Glad you got it!

Thank you for the great instructions.  Would you mind explaining the steps in a bit more detail.  Flight modes 2-6 are working for me, but I'm not getting a signal low enough to hit Flight Mode 1.  I got this working by changing some of the values and watching the modes change in Mission Planner.... but I really didn't know what I was doing.  I'd love to understand it better.

Thank you,


Airplane mode always. The reason why is Heli is a special mode from the radio standpoint as it's set up for collective pitch. That means the radio mixes both the throttle channel and the collective pitch channel and that is no good. Airplane mode normally has no mixing of channels by default.

All of that is covered in the radio manual if I'm speaking Greek to you.

Step 1: the TX settings.

Endpoints are what lets you determine the "range" the TX will send to the APM via the receiver, thus in order to get a lower bottom end signal, you must adjust that endpoint. That's going to be in the radio manual, not the manual for the APM because they cannot cover every possible radio. Hint, it's a good time to actually read that thing.

Sorry, but you must look at this like it's an RC aircraft first, and then the APM adds functionality. So the keys to setup are getting the radio system correct and again, thats in your radio's manual. http://www.spektrumrc.com/ProdInfo/Files/SPM8800-Manual_EN.pdf


The reason he set up a mix in the radio is that by default, most radios only have 3 position switches but you need 6 positions on one channel. By using what would normally be 2 separate channels at the the TX, then mixing them into the single channel that the APM understands gives you 6 positions. This is covered on page 29-30 of the manual for the TX that I linked.

I realize this is probably a lot to learn, but that's the problem, the system is made of many components from different manufacturers and you are they builder of the system. You have to know how each piece works and then how that integrates into the system. Basically, you must be an expert of the radio since again, this is an RC aircraft first, then the APM only adds functionality. Just as if you had a servo you wanted to hit 6 dedicated positions, that's a function of the TX settings and really has nothing to do with the APM. All we do at the APM is detect those 6 different positions, and then assign them to a function. It's the TX's job to get us those 6 distinct postions.

Sorry if any of that sounds like I'm harping on you, I just want to point you in the right direction and one piece of that is learning radio control standards like the back of your hand. If you understand the TX settings, mixes and other functions, then you can achieve the proper outputs at the receiver side, The APM cannot do anything unless it get's a signal it can deciper from normal. Basically, it's just like a six position switch attached to a servo. You must adjust it so it stops on each of the 6 contacts. The analogy is that is you can set this up is the physical sense, then the APM becomes a snap.

Thanks.  I've read the manual.  It's not the concept I was struggling with, but some of the values in the steps that were listed.  I did get it working and do understand the goal... there's just a piece of the understanding where the lightbulb hasn't clicked yet with regard to the endpoint percentages selected and the actual numbers produced.  These are clearly different on each radio.  I'll figure it out, anyway, thanks for the reply.


You've got to admit that the Spektrum manual isn't exactly clear on all of this and mixes are frustrating.  I remember trying to figure out mixes when I began and it's anything but intuitive.  Heck, I still don't understand why I'd want to mix a channel into itself.  And there's really nothing in that section you mention that would lead somebody to believe that you can mix switches together; it's totally oriented to mixing rudders, elevators and the sticks, not the switches.

This is why I've posted 2/3 to 6 channel detailed instructions before for the DX7s and if others have them for other transmitters, it will really help people with what they need.  They'll also probably learn a lot about mixes on their transmitter as well.

Thanks Bruce.  You're right.  The manual wasn't very hepful.  I'm found I learned more by reading the forums and experimenting with settings while viewing the output in mission planner.

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