Control Elevons? Where to plug this in? How long to charge?

[diarmaid]

Hi all.

I need a bit of advice so I broke it into 2 parts. This and the following post:

Ok, heres the problem:

I need to control two elevons (Control surfaces serving as both elevators and ailerons) and am trying to figure out the servo control.

Is there a particular type of servo I could buy (Which would probably come as two servos, but allow a combination of synchronous movement and opposing) to do this or am I going to have to go down the route below?

Is the route in italics below even appropriate? If necessary I'll fork out a few hundred for a computer r/c transmitter.

In the next post is a pic & details of my current radio controller and servos. Transmitter is not a computer radio. I will probably be getting different servos with higher torque but thats not relevant now, just so you know that this is what Im looking at, and I want something different because I cant see how this will work! (Pause to breathe ) Although I would prefer not to buy a new transmitter...

"I'm not sure yet what combinations of mixing will work well on this jet for pitch control--all I know for sure is that the mixed controls I've got now work extremely well as is. To achieve this on my Futaba 9C transmitter, I did the following:

* Plugged the canard servo into channel 2 (elevator)
* Plugged the two elevon servos into channels 1 and 6 (aileron and flap)
* Enabled the Flaperon function for the two elevon servos
* Enabled elev->flap mixing and dialed in 50% mixing (which makes the elevons both deflect up when the canard is deflected trailing edge down)

With the 50% elev->flap mixing, full aft elevator stick produces about 20 degrees canard deflection and 10 degrees elevon deflection. A computer radio with mixing is required to achieve this.

While I do intend to test other mixing scenarios (including canard-only and elevons-only), I am skeptical either of those will work well."

[diarmaid]

Ok, in the pics below you can see what I have now. As you probably gather from the pics, the servos have been 'rescued' from abandonment in the attic. The transmitter and receiver batteries are charging while I type this so don't know yet if they still work!

Anyway, the first simple question relates to the single cord in the pic below. One end connects to the receiver battery, and one has a fitting that will go into a slot on the receiver. What slot do I put it in? the receiver slots are numbered 1 through 6 and the top one says 7/8. I dont see any slot that says power in?

The second question: Can I use this 6 channel transmitter to control my elevons? There is technically enough channels. 1 for throttle and 5 left.
The two knobs on top right and left say Elevator D/R and Aileron D/R and have two positions one marked 'on'.
On the top there is: A 'Retract Gear' switch. There is a 'Trainer Mode' switch, which I think gives control to a teacher when your learning. There is an 'AUX' switch with 3 positions simply marked with a right and left arrow and a dot in the center position.

Its a Sanwa Vanguard VG6DR Radio.
The 4 servos just say Sanwa SRM 102.

Thanks for any help folks.

Sorry about the pic quality. Took them on my phone.

[diarmaid]

Oh yeah....one more question ....sorry.....anyway, how long should I charge this for? A vague memory say 4hrs but I could be wrong. Cant find the manual

Edit: One more question!!!...What do the Elevator and Aileron D/R switches do? Thanks.

[diarmaid]

I found another possible solution. Would an elevon mixer be a possible solution?

http://www2.towerhobbies.com/cgi-bin...?&I=LXELT4&P=M
http://www.welwyn.demon.co.uk/vtail/vtail.htm

[unterhaus]

my radio will do mixing, doesn't look like your radio has that capability. Otherwise, there are mixers you can put in the plane. Sorry I didn't read all your posts.

[diarmaid]

Sorry the posts are a bit long I probably should have broken it into a few threads. Thanks for the response. I was worried about plugging the bty into the receiver incase I shorted something, but I risked it anyway. The bty can be plugged into any of the slots but slots 1-6 control various features, therefore slot 7/8 is best for plugging in the bty. Everything still works.

[epineh]

Originally Posted by diarmaid Edit: One more question!!!...What do the Elevator and Aileron D/R switches do? Thanks.

D/R stands for dual rate, this generally halves the travel on the servo's.

Useful for an overly responsive model you want to slow down to make it easier to fly (or drive, float etc)

Be careful, sometimes it can have disasterous results (ask me how I know) for a new model if the switch is on unintentionally on a maiden flight and your plane doesn't respond well enough to control well enough...

Russell.

[diarmaid]

Thanks epineh. One to be careful of I think!! Any pics of the big crash? (Or did it have a happy ending? I forgot that thanks to the D/R controls, I once had an incident with an unfriendly pine tree. The tree came off better than my trainer! And thus ended my model flying carreer...)

I have a new small problem. The mixer's I've been looking (See above links) at have two inputs from the receiver and two outputs to the aileron and elevator servos. I dont want to have seperate ailerons, I want to simply mix the aileron control into the elevator servo movements. Thus giving me 'elevons'

Could I achieve this by either:

Using two (2) elevator servos connected from the two (2) mixer outputs, and connect one servo each independantly to the left and right elevon. Or will this make the elevator on one side move differently from aileron transmitter movements with no real relation to the one on the other side which is responding to the elevator controls?

or

Just connect the elevons in the same way as ailerons, using one servo plugged into the mixer, and just leave the other output unplugged. Will the 'mixer' incorporate my elevator movements into this aileron servo movements?

Thanks for any advice.

Basically, I'm slightly unsure of exactly how the onboard mixer interprets and processes the output for my controls. Therefore I dont know in what way the appropriate outputs can be achieved.

[epineh]

Well there were photo's of the crash, pretty funny too, but I'm not sure where they are now (long story) I'll post em if they show up.

I've been out of RC flying for a while so don't quote me on this...The mixers look they would work, never tried them personally, had computer radios with all that stuff on.

I had a model with "flaperons" which is similiar, ailerons until you flick a switch and both ailerons drop down to a preset level and presto flaps that work as ailerons. Now I'm pretty sure you will have to do the same as my setup, that is to have one servo for each control surface, the mixer simply adds or subtracts whatever input you change to the pulse width modulation and the result is (hopefully) control movement.

The flaperons worked a treat, I had a CAP21 that I could land on a jellybean flying not much quicker than a fast walk.

What is the model? .... I'm guessing one of those flying wing things, either that or a scale stealth bomber.

Russell.

[diarmaid]

Thanks Russel. Well that clenches it! I'm going to buy one and mess about with it until it works. I e-mailed ken about the workings of his v-tail mixer above but no reply yet. I think I'll buy the tower hobbies one though, looks less complicated. Its just for a little project Im working on...not exactly your 'standard' model...and its a secret ...but I'll let you know how it all works out in the end. Thanks. L8rs.

[diarmaid]

Ken Hewitt e-mailed me back about his V-Tail mixer and simply said to plug the two inputs into my receiver and the outputs into my two servos, and the result will be two elevons. Problem solved. I might buy his now since he was so helpful.

[vulcom1]

Not sure if that will work but you can try. The name to look for from my Futaba manual for setting ailerons and elevators together is called ailevators. This is a mix on the computer types and on mine it is P2 on the mix switch. Maybe do a bit of a search on that subject.
Battery charging usually with the standard charger for the radio is 50 ma. If it is take your battery capacity and divide it by the charger ma's. 600 mah battery divided by 50 gives you 12 hours. Packs and chargers are different sizes or outputs but the calculations should be the same. This is what they call the C10 rate which won't hurt them. Fast charging is a different story because then you have other things to look out for. Heat is the big problem.
John