DX8 setup question
 

Just got a DX8, and am setting up my eflite RV-9, and was wondering what setup I need to use for the wing type. I have 2 aileron servos, but they are y-cable connected to one channel. The two configurations are two servos (one per channel, or one servo, one channel. Dont see any option for two servos through one channel. Which setup should I use.

I am also using flaps on this plank, and was wondering what elevator Ineed to mix in, as I increase flaps deployment. Do Ineed to add up elevator or down, as I increase the flaps down ?? Thanks

RE: DX8 setup question
 

The flaps "usually" need down elevator, the only way to see is to fly it though.

1 servo one channel is correct, though I don't like Y harnesses if you can avoid using one which should be pretty easy with that radio.

RE: DX8 setup question
 

So you are suggesting that I run each aileron separately? Right Aileron in Ail channel and Left Aileron in Aux channel? to be able to fine tune each aileron servo individually? I gotchya.

RE: DX8 setup question
 

Yes thats exactly what I'm suggesting. So in that case you'd set two servo/two channel and that way you can adjust sub trim on each servo, setup aileron differential, etc.

RE: DX8 setup question
 

OK, that makes perfect sense. I appreciate the help.

RE: DX8 setup question
 

You can run 2 aileron servos through a Y-harness with no problems. Just plug them into the aileron channel and to the radio they appear as one servo when on the Y-Harness. I've been using Y-harness for 15 years and never had a problem with them. They are the simplest and easiest setup you can use, and require no additional programming in the radio.

Hope this helps

Ken

RE: DX8 setup question
 

Yes yes, and you can lick a stamp to send a letter too, fortunately we've progressed since then :D

RE: DX8 setup question
 

That's true. But when a stamp will work why take the expense and extra effort to do anything else?

Ken

RE: DX8 setup question
 

For a beginner, heck.. for an advanced pilot, a Y cable is the most simple and works just fine.

RE: DX8 setup question
 

But its far cheaper to send an email vs. a letter... mixing in the radio is a little cheaper without the y-harness.

RE: DX8 setup question
 

Of course teaching someone who has just started learning how to read, to send and e-mail ( and computers in general ), is far more difficult than showing them how to lick a stamp! :D

RE: DX8 setup question
 

Cheaper.. by perhaps a few cents. Perhaps equal to the cost of a stamp.

CGr.

RE: DX8 setup question
 

depends on how many stamps you need per letter and how many letters you send.

RE: DX8 setup question
 

Yep, stamps still work: One good way to save money is to place a 2 Cent stamp on envelope. Many years ago, Congress affixed postage at 2 cents. That has only been changed by the USPS. If you place the addresse's address in the return address block, they always get there. 100 44 cent stamps = $44.00. 100 2 cent stamps equal $2. $42 buys a Liter of Jack Daniels. Works fer me!

RE: DX8 setup question
 

Hossfly, you the reason the USPS is in da red! :D

For the first time flyer, just go with the y cable. Learn to program after you fly it for a while and start getting bored, and need something extra to do. You will use 2 channels in the future, don't complicate things for yourself. Remember to label the cables so you can't hook them up to the opposite channel when you do use 2 channels. It is a common mistake when using 2 channels for ailerons. I bet no one on RCU has ever made that mistake...

RE: DX8 setup question
 

DJensen: What to take from this?

There's more than one way to do things right in this hobby. Find what works best for you.

If you go the dual servo, dual channel route, I'll be happy to walk you through the simple programming.

If your betamax VCR isn't still flashing 12:00 12:00 12:00 it will only take you a minute or two to set up.

RE: DX8 setup question
 

Thanks Cuda. I appreciate it. I guess the others posting here would rather gripe about stamps vs email, than stay on topic. At least someone is here to help. I maidened the bird last night with the y connector, and it flew great. Trims were almost perfect, just by spending a little extra time during setup to get everything the way it should be. The only thing I need to adjust is that with flaps down, she wants to go a little to the left, so I just need to adjust the right flap linkage up maybe a half to a full turn, but shouldn't take much more than that. I am going to take your advice and setup with separate aileron servos on separate channels. I like the idea of more adjustment if needed. I'll give it a whirl, and Ihave any questions, I'll send you a PM, so we don't clog this thread up for the others that are concerned about our postal service and various internet communication media. Thanks again.

RE: DX8 setup question
 

Hey, WAIT.... I used to lick stamps and stick them to my baby brother's forehead. You can't have much more fun than that! (Until Dad and his size 36 belt got home!)

RE: DX8 setup question
 

Y-connector works great. If I'm running two servos, I personally prefer to have dual aileron set up. This way you can do sub trim individually for each aileron to get it set up perfectly. Its also super easy to program in any differential, etc if you need that, which you cant' do with a Y-harness.

RE: DX8 setup question
 

Oi! Dont get them started on tinkering with mechanical linkages for aileron differential.

Yes it can be done but its no where near as easy as with a radio program.

RE: DX8 setup question
 

Nope you were being helped... the "stamps" analogy retort was an attempt to explain to a more experienced member that he was complicating things for you needlessly.

The "Y" cable arrangement is the simplest way to go about your setup.

BTW: Setting up mechanical differentials using your "Y" cable is trivially easy too. All you need to do is have the TX at stick center, then position each of the aileron servo control horn arms canted forward by an equal amount on each side. The more forward the horn position, the more differential you get.... nothing to it...

But that's for more advanced trimming and tuning, and may be beyond the scope of a beginner's section.

RE: DX8 setup question
 

Well, it was actually BarraccudaHockey that started the whole "analogy" with the stamps, but we'll forgive him for that because he's a pretty good guy otherwise!!!;)


Seriously, OPJose is absolutely correct about the context of this thread. This is the Beginner's Forum and our advice is usually geared for beginners in the hobby. Yes, Barraccuda is absolutely correct that you can use two channels and make your adjustments in the radio. And many more advanced pilots do just that. But this could cause problems for a beginning pilot if they don't understand correctly the proper setup of a plane.Unless you are sure that your plane is mechanically correct before you start making adjustments in a radio you could possibly put your plane at risk because you could wind up with a control surface that won't function properly. This is why Itry to teach people to learn to mechanically adjust and setup all control surfaces before they ever start making any adjustments with the radio. And in the context of the Beginner's Forum that is why many (including myself) made recommendations for using the Y-harness. Had this been some of the more advanced forums then this would probably never have come up like this.

Ken

RE: DX8 setup question
 

Again, I am thankful for everyones thoughts and inputs here, and I know it can be hard to stay on topic sometimes, which is very understandable.

Well, Itook my plane to the field for its maidenlast night, and had avery experienced pilot take it up for its initial go around. Afterabout2 minutes, and him not sayingone single word, I finallyasked him how it was. He asked me again just to verify, that he was flying the initial flight. I said "YEP !! Hasn't even been outside til today, why do you ask that?" And he said that he couldnt believe how well I had it set up. Not one bit of roll left or right, steady level flight, perfect CG with battery where I had it initially, he literally got it up into a straight level flight, dropped both arms to his sides, and watched in amazment, as it just stayed there in perfect straight flight. He reached up, grabbed the transmitter (still without touching anything at all) unhooked it from his lanyard, and handed it to me, and said"Here ya go,its yourplane. Flyit.Ifyou can't fly this, you will never be able to fly!!

To make a long story, well I guessI didn't really make it all that much shorter, but anyway.He said Idid an outstanding job assembling the plane and getting all the linkages centered and making sure all the electronics were working properly, and that is why it flew so well. Ijust made sure that everything was done right. I would rather spend an extra day or two makingsure the assembly is correct, than a couple weeksfixing something that could have been avoided from the start. I have built quite a few helicopters overthe years, and after knowing what to look for, its pretty easy to get them set up right,before you even fire it up. then just use the radio for extremely fine tuning, and personalization. A littleextra time in setup really does go along wayin the end.

However, I did have aslight problem with the assembly of the elevator.The control surface has holes predrilled for the horn to go thru, but they were on the wrong side on my kit. The elevator was assembled from the factory backwards. The horn mounts to the underside of the elevator, on the port side of the plane. The rudder horn is on the starboard side of the rudder surface. If I followed the directions, both horn would have been on the same side of the rudder. The directions are correct, just that the elevator surface, was backwards when mounted to the horizontal stabilizer. However, I called Horizon, and they were more than happy to send me out a brand new stabilzer set (both horiz and vert stabs) and a complete hardware pack.

As much as I am a noob to planes, I do understand the concepts of how these radios all work, and how they mix, etc.

What is aileron differential, and what are the advantages and disadvantages ? Thanks.

RE: DX8 setup question
 

A down aileron produces more drag than an upward deflecting one. So if you are rolling to the right the left hand aileron goes down and produces more drag and it pulls the nose opposite the turn, a situation called adverse yaw.

So you can either tinker with the linkages or take 30 seconds to set it up in your radio such that the downward ailerons dont deflect as far. Forutanetly they know what we want so there's a pre-configured mix and you just tell it what percentage and give it a shot starting small and working your way up.

You can also counter it by adding a bit of rudder in a coordinated turn.

Not all planes need it.

RE: DX8 setup question
 

Sorry, Iguess I should have worded it differently. How would I go about setting it up into my radio. I know what it is physically doing at the plane. How do Icombat it? are there any downsides to having this mix in your setup?