What use are more channels?

[bdhowe]

Looking to buy my first radio, and I'm wondering how far I can get with 6 channels. This might sound pretty ignorant, but seems to me that 4 covers the fundamentals (throttle, ailerons, elevator and rudder), so in most cases I'll have two left over for clever things like flaps, gear, and cargo doors.

On what types of projects would you start needing an 8+ channel radio?

And one more beginner question - I presume you are able to map your channels to different controls on the radio, like the various switches and dials on the top. The DX6e has more switches than channels, so they can't all be working at the same time, can they?

 

[rockyboy]

6 is plenty to get going with for sure. Personally I end up using a 8 channel radio when I use separate channels for each aileron servo, and separate channels for each flap servo, and then throw in a buzzer alarm all controlled via radio. And then wouldn't it be neat to have night lights on a radio switch too? But it's absolutely possible to run those aileron and flap servos off Y harnesses and therefore only need one radio channel to run both servos and keep everything happily running on a 6 channel radio for most models for a long time.

Someone else will need to help you out with the Spektrum questions though - I'm running Taranis radios myself and every switch is assignable to every function possible in the radio programming. But too much power can be dangerous... and confusing

 

[Crazy Goats]

With the dx6e, I suppose it is like my dx6i. The extra switches are for rates and mixes.

 

[kacknor]

You just never know.

3 channels will make many FT planes fly. Four becomes cool as ailerons are a good thing when you can used them. Then, out of the blue, you get this crazy idea that if you use two servos for the ailerons and a radio channel for each, you can make them work as flaps too! After that come actual flaps, and then each on it's own channel and the glider you are flying now can have either full wing ailerons or full wing flaps/spoilers or split spoilers and ailerons and... You get the idea. Don't worry yet about adding lights and a way to switch them on and off, or landing gear and bomb drops or all that other cool stuff.

Don't get me started on telemetry and how useful it is to know the battery charge left or the location/speed/altitude of the plane.

You just never know.

JD

 

[LitterBug]

Well, if you ever end up getting something with a flight controller, you will be wanting those extra channels for things like arming, selecting flight modes, enabling beepers, changing OSD screens, turning on lights, yada yada yada....

You can mix switches with other channels/switches. They can also be used for changing rates of one or more channels. 6 channel is a good first radio. I had a DX6i until I ran out of model memories. Then upgraded to a DX8.

Cheers!
LitterBug

 

[CrossedUpChris]

Remote operated solid rocket booster

 

[bdhowe]

Well, I'm definitely going to need to remote light a rocket, so I'll make sure I have a channel available for that.

Sounds like the DX6e is a good place to start but the Taranis is the ubernerd radio. The other thing I'm seeing is that most of the BNF stuff is DSMX, so you have to have a Spektrum in your box if you want to play with those. Looks like I'll eventually end up with two radios.

Do you split your ailerons for additional strength, or is there benefit in being able to control them separately?

Telemetry doesn't consume one of your radio channels, does it?

Why are people around here so nice? I haven't even built anything but I already feel like I'm in the club.

 

[PsyBorg]

Why are people around here so nice? I haven't even built anything but I already feel like I'm in the club.

That's just how we roll here.

Extra channels lets you do many things depending on what you fly. Could be for bomb bays, lights, camera operation, landing gear, candy ejection, parachutes, para troopers. As well as traditional Flight Test things like turning on the toaster or microwave mid flight or even blending your margaritas while airborne. For jet flyers tail hooks for scale operations. Things like sound modules to turn them on and off, For multi rotors you have arming, lights, flight modes.

More switches like on the Taranis or anything that runs open source programming that can be setup to give vocal read outs, play music files while you fly, reset timers.

But as many have said 6 channels will take you pretty far in the hobby. The Taranis also can use modules so you don't have to invest in a whole separate radio system for different protocols. Now that the Q7 is out that is right in the same ball park price wise as 6 channel systems with all the benefits of the X9D plus only less physical switches.

 

[pressalltheknobs]

Well, I'm definitely going to need to remote light a rocket, so I'll make sure I have a channel available for that.

Sounds like the DX6e is a good place to start but the Taranis is the ubernerd radio. The other thing I'm seeing is that most of the BNF stuff is DSMX, so you have to have a Spektrum in your box if you want to play with those. Looks like I'll eventually end up with two radios.

Do you split your ailerons for additional strength, or is there benefit in being able to control them separately?

Telemetry doesn't consume one of your radio channels, does it?

Why are people around here so nice? I haven't even built anything but I already feel like I'm in the club.

Switches are used to enable and control mixes in addition to channels so the number is not really dictated by the number of channels...but also the supported features.

If you are buying a Spektrum TX then the channel issue comes up because Spektrum's marketing approach is to have you upgrade your radio when you want/need more channels features and functions. Many people don't go beyond 6 channels but that is partly because once you have a decent 6ch radio, doing so is cost prohibitive for some little feature that you can do without. It's not worth the trouble of forking out the $400 to $1000 and maybe selling on your old radio just to get the pilot's head to turn when he flies buy.

That's why the FrSky radios are such good value. With the X9D+ you get 16 channels (up to 32 with an additional module) and 2 pots, 2 sliders, 5 3-posn switches, 2 2-posn switches and a momentary...plus the usual complement of sticks and trim switches. All come unassigned and can be used for whatever feature/function you want to set up. And it costs about the same as a DX6 (Transmitter only) so if you never use them well no loss but if you suddenly feel the need, there they are. The new Q-X7 has a few less pots and switches and some other minor limitations but is similarly capable and it is much less than the DX6e (the Q-X7 is new so difficult to get right now). The catch is that the X9D+ and Q-X7 run OpenTX which has a steeper learning curve if you expect a similar menu system to Spektrum...you can implement just about any function you can think of but you will have to read around...once people get over that they generally find it's flexibility much more rewarding than other approaches.

Not saying the X9D+ or Q-X7 is right for you but if you are asking about channels now, my guess is 6 won't cut it for long.

If you want to fly Horizon BNFs "NOW" then the DX6e is going to be the better immediate choice. It's reasonably priced and should hold its value pretty well so it wouldn't be a mistake. Personally, if you are going that route , I think the DX6 has better features and is probably worth the extra $50 but I haven't tried either and that's a slippery slope of an argument. ...Why I chose an X9D+.

Telemetry is done different ways by different systems but does not typically take a "channel". With 2.4Ghz systems typically control data for the channels is sent in one packet and the telemetry data is sent back as a different packet. In some protocols a control package is missed in order to make time to receive the telemetry packet, in others the telemetry packet is returned between two control packets. In some systems the control to telemetry packet ratio is fixed and is others you have some control over the ratio of control and telemetry packets.

Separate aileron control allow you it implement differential ailerons, flaperons and spoilerons etc.. For strength in larger planes you may have multiple servos on a single control surface. Here separate channels are used to tune the response of each servo so the whole aileron moves smoothly and does not distort because one servo pushes more than another.

 

[rockyboy]

Yeah, this is definitely the online forum that doesn't suck Whenever we want to talk about other cool hobbies like 3D printing or CAD/CAM machining or learning amateur radio frequencies, we end up creating a forum area here cause the community is great and helpful.

I'd also give a +1 to the Taranis Q X7 as a great radio that will grow with you a long time and isn't a big investment. I've just got mine in hand and connected to the computer for the first time now, and it seems like a great unit. All the awesome power of OpenTX in a more durable feeling case - just sans a couple of the extra external controls. Don't know how they are able to sell it at half the price of the X9D+