No matter what servos you use you have to match them up....Since all your using is 2 servos per surface this is easy to do especially on the rudder. If they are not setup right (Travel Adjust and linkage) you will have problems.....

This goes for any of the servos....even the Hitecs that are programmable...basically what you are doing is programming them for end point, center and so on.....just like a matchbox or what your Computerized TX can do.

The big issue that I have seen with the programmer and has been brought up with users of it...the servo is programmed away from the TX inputs....So you don't know what the exact output of the TX is and thus you can get a mismatch there also.....I'm not an expert on the programmer for the Hitecs.....Just going on what I have seen and heard. The programmer is cool and allows a degree of freedom....but its not the end all answer and just because you used the programmer doesn't mean the same setup stuff will not apply. Its more a case of where you do the setup....in the programmer, in the TX, or in a Match Box.

I can speak with confidence on the JR stuff. A match box merely makes a 2 servo setup easier since everything is away from the TX....The matchbox takes the signal that is going to that channel and allows you to match the servos up so that they move the same are reversed properly and so on.....It is best used when 3 or more servos are mixed or when you have so many servos mixed you are running out of program mixes and channels to mix with.

If you are only using 2 servos on the rudder this is easily done the same way in fact the exact same way using the Travel Adjust (ATV), subtrims in the TX....... and then proper linkage setup......

I know its not the easiest thing to setup when dealing with these big monster 33%+ planes but it seems to be a necessary evil....The matchbox really excels in setting up more than 2 servos per surface...like if you wanted 3 servos on the rudder. Or you wanted to put 4 elevator servos all on one channel with no "Y" and no dual elevator mixing.

The 8411's have become very proven with guys using 6-8-10+ per airplane....Like anything else it takes time to setup properly and once its done you are good to go.....By the way after you do it a couple times it becomes second nature and its not a big hassle.

Len Alesi wrote a great document on setting up a 33% airplane with multiple servos on the control surfaces....

Its at the Horizon Hobby website. Its worth a read on how he does it.....I do my stuff the same way. It works very well...Not only that but it works for all setups.....

http://www.horizonhobby.com/articles/1169.asp


Futaba, Hitec JR or Airtronics his practices work the same and will help you get them setup properly. All servos have electronic differences and most of these are small 2% here 5% there...no 2 electronic components are identical.

I don't think that switching servos to another brand is going to resolve your issue...

I may be off base and you just had a servo that was not up to snuff.....but I have seen it more often than not......guys don't have the servos matched properly in the TX in the geometry or both......They work hard at it and give it a good shot but in the end something is off....Usually its Geometry....No matter how many matchbox's or servo programmers or different brands you try Geometry is going to be the killer.....

***Servo arm 90deg to the pushrod (ignore 90degs to the case) Its gotta be to the pushrod...... subtrim the servo until this is correct. Try different horns on different servos all plugged into a Y harness on the exact same channel....match them up here so that the subtrim values to get them the same are as small as possible.....Don't want one servo with a 100% subtrim and another with 3 %....Something is wrong if this is the case....You don't need 20 servo to find 2 that are close...all the brands are pretty close...Just match the ones you have the best you can. It will make life easier in the end.

*** Control Horn/clevis pivot point (on the surface) directly over the hinge line...I mean right on it...so they are in the same plane...and matches the horn on the other side. (bend the bolt slightly to achieve this or re-install it is a better solution.) This one is tough to get as drilling the holes for the bolt are not perfect....a slight bend in the bolt is OK here....but not anything major. I'm talking 1/16" or less bending adjustment....Any more and you will weaken the bolt. If the pivot points are not exactly alike and on the same plane as the axis of rotation....The pushrod links will not both have the same forces or loads on them....One might be moving easy and the other the servo is pushing back against it....the ....Example a door hinge with one hinge not aligned in the same axis....The door will bind.

*** The distance from the control horn/clevis pivot point to the axis of hinge line exactly the same on both servo linkages...(this one gets tough usually a 8-32 or 10-32 bolt and you are limited by 1/32 of an inch or whole turns...) But this will work...and get it as close as possible. The Travel Adjust or ATV will take care of the minor differences.And I mean minor ones only

*** next is slop free. Good ball links, or clevis type devices

*** no binding at the ends. What I do is hook up one side to the surface and then just position the other ball link or clevis device in place....first check the center to make sure it aligns perfectly and is just not connected. Adjust the rod length if its off slightly....Then I move the surface and make sure my 2nd servo and linkage tracks all the way with it and stays aligned. But its still not connected. If it doesn't then Travel Adjust (ATV) so it does. This is the step where the Matchbox, the programmer or you mixing setup in the TX takes over....It doesn't even count until this step. You could program the servos with the programmer exactly the same....but the electronic components in your TX or RX could see slightly different values that same 2% 3% or 5% difference. The pots in the TX are just like the pots in the Servo they vary. This is the last and final step to make sure everything is cool, and no matter how you do it.....It all hinges on this step. All the previous steps allow for less headaches here.

Note if you hook the 2nd servo up you won't know where the binding is and both servos will buzz.....I use the main servo #1 as the master and "match" the other servo to it....What ever the master does the second one matches end points, centers and so on....

The JR 8411 is so precise and so strong that if you don't do things this way they will fight each other and I have even seen guys strip the 2 servos out..they actually were so far at of whack they stripped each others gears. And the guy flew them 20-30 flights setup that way before they gave up! He was shocked because he had spent an hour setting them up and they didn't break right away so his setup was OK right?

I hope this helps...Its a complicated issue and different companies have different solutions. All of the current solutions require the same steps for the setup.

I'm not alone in this opinion but I think you have the absolute best servo on the market today for doing what you are doing....They are not perfect...but they are the best solution available! Not only that but compared to 5 yrs ago they are light years ahead of where we were back in those days.

The guys using Hitecs, Futabas or Airtronics will argue this fact based on brand loyalty.....like the Ford, Chevy or Dodge trucks argument but they can't argue the steps to setup any of the brands....Some will do more....in the setup process but I can't see it done properly with any less attention to detail. Regardless of brand of servo, brand of radio or servo performance.

Good Luck

Troy Newman