Calvinman

Hi to all, I am building a Ultrasport 40 or two and I am putting in flaps at 1/3 original aileron length which is 8" the remainder of the aileron will be, well aileron. So my question is, will a futaba micro servo S3114 at 20.8 oz.in torque be enough to operate a 16" aileron of 1" cord. I read in another post that it is ok to use a micro for one aileron, but the info sheet in the servo box says only use for small electric models. Also, when using a "Y" adapter does one servo rotate one way and the other in the opposite direction? If this is so I can install my servos without making sure the rotation is going to be correct as long as I make a mirror image mount on one wing, then if my ailerons rotate in the wrong direction, I just have to flip the "Y" connector Right??Calvi.

JohnBuckner

My Feedback: (1)

Hi calvin first a lot of questions here and none have simple answers perhaps except the choice of servo and that answer is easy, A very poor choice in servos. First its not about if the torque is going to be enough it is all about vibration and the ability of the gearsets to withstand the loads in a high vibration environment. Futaba answered that for you with a warning about only using this servo in gliders or small electrics, pay attention to that warning.

OK if you have to have flaps I think choosing to separate flaps into independent surfaces (using a four servo wing) is a far better idea than flaperons. The specific servo I would choose for the job both the two aileron and the two flap servos would be Hitec HS 225 metal or plastic gears. This is what many consider to be a 'Mini' not a 'Micro'.

Now yes you are gonna have to pay attention to servo orientation and and linkage if you are going to avoid the headache of reversing servos or reversing Y's and so forth and its so simple since you will be installing the second set of servos yourself:

First install the aileron servos as normal with the out put bushing both pointing toward the wingtips of both pointing toward the center of the airplane. Now no mystery there. Next, for the two flap servos unlike the aileron servos you position them so that the output bushings of both servos are pointing toward the right side of the airplane or both servos output bushings are pointing toward the left side of of the airplane.

Its that simple all you need now is a standard Y chord on the flap servos and you operated the flaps through on single channel.

Last but not least and here come that word 'Opinion' agine and it definitely just mine: Forget the whole flap idea its not worth the effort, even kinda silly for that airplane and nobody else is gonna even know you got'em



John

bikerbc

I do not think I would use those servos for your ailerons and flipping your y harness ? I am not sure what that means but no you would need to Run the arm from the other side of your servo . One servo off one side and one off the opposite side so that while one is pulling the other is pushing...I hope this helps.. You can get servo reversers but it is probably better to just set it up without ..The less electrics to go wrong the better..

JohnBuckner

My Feedback: (1)

Actually that is not quite right biker for dedicated flaps (not flapperons) It is opposite of what you described, that would be correct for ailerons but two flap servos using a standard Y cord (the simplest method) would be as I described with both output bushings or servo arms pointing to either the right or the left wingtip.

Both must push or pull 'together'.

And yes I agree with you the less complication used the better will be the result.

John

Top_Gunn

My Feedback: (6)

The only real advantage of using small servos is weight saving, and the Ultrasport is a plane that doesn't mind a bit of extra weight at all. I'd recommend standard servos for the ailerons, set up as John Buckner described. There's no need to use more than one flap servo, though. Because the flaps are made from what would have been the inner parts of strip ailerons, you can use the aileron torque rods you get with the kit for the flaps. Just connect both of them to one servo (mounted where the plans show the aileron servo) with a forked pushrod. There's an Ultrasport build thread on RCU (I think in sport flying, but it could be kit building) with a lot of good advice and pictures. Well worth checking out.

JohnBuckner

My Feedback: (1)

Yes indeed Top_ Gunn that would work very well, It slipped my mind that the original torque rods would already be in place. Thanks for pointing that out.

John

Calvinman

Gentlemen, Thank you both for your answers, I should have posted before I purchased the micro servo's, but oh well, at least I didn't loose a plane due to lack of asking. And yes I was gong to use a single servo for the flaps. I don't know why I just have to have flaps on my UltraSport, but I just cannot build one or two without having tried flaps. Yes I think I will use standard servo's for the ailerons, and I am still not sure, does a "Y" connector have one servo move opposite to the other servo? If it does, I can plan out my servo installation, I would like to mount the servo sideways so just the arm sticks out of the "hatch" cover for the servo.Thanks for your advice, Calvi.

JohnBuckner

My Feedback: (1)

Calvin a standard Y cord does not alter servo rotation in any way. A reversing Y cord does reverse the rotaion of one of the servos. These however often involve some electronics under shrink wrap and usually an adjusting pot to match up the two servos. I am not a fan of those as its just more stuff to go wrong and as always adjustable pots are subject to corrosion and subject to unnecessary problems.

As for the extra servos, Well don't you know a mans kingdom is always judged by how many servo's he owns

One last thought on the rotation thing in this situation another old time trick you can do and I have done just that where I had separate dedicated flaps with two servos. If the servo rotation thing becomes a problem you can also use a Futaba servo on one side and a similar Hitec on the other side. For flaps that works fine. You see Futaba and Hitec servos by factory default have opposite rotation from each other.

John

Calvinman

Thanks John, I will just have to have the "Y connector in hand hooked up to my radio so I know how to mount the aileron servo's, not a big deal, just another step before I start gluing up the wing. I am not interested in a reversing connector, it is just more stuff to go wrong. And yes John, you are right, my kingdom is now a little more powerfull, this morning I am meeting a fellow RCer who is selling his glow engines, glow field equipment and such because he has gone all electric. So the two mini's may give me an edge in bartering with him Calvi

Calvinman

Thanks for the heads up Top_Gun. It should not be difficult to do(mounting the aileron servo's sideways, but sometimes I do tend to do things the hard way, so it would be nice to look at what someone else has done. I did find a thread in sports flying, and the builder did install flaps as I am doing, but he did not show any details. I will have to look further into the sport fliers section. Now that I know that the "Y" connector does not change the rotation of one of the servo's then I can install the servo's with that in mind and if rotation is backward just reverse direction with the radio. Well I did not trade the micro's for the RC stuff, but got a great deal(I hope) I got 7 or 8 engines, same amount of tanks(stoppers seem to be not rotten) 4 radios, and a sandwich bag full of servo's(S-148's) Not to mention nistarters, glowplus and all the chargers, I will list all the engines later tonight if anyone is interested. Also metal motor mounts for most of the engines.Calvi

Ed_Moorman

My Feedback: (1)

Calvinman,

You have 2 primary controls that, if they fail can kill your plane of hurt it bad. The elevator and ailerons. Don't go cheap or under powered for those surfaces. You are just asking for trouble.

The US 40 is going to go 75+ mph with a .46. Think of the air loading when you stick your hand out the window of your car at 75! Next, those tiny little gears in a micro servo, and I don't care if they're metal gears, they are not made for that size plane and power. Third, micros are generally made for electrics that have no vibration. A glow engine will shake the guts out. I've tried those for throttles and had to go back to standard size. Don't take a chance.

Nix on micro servos on a .40-.55 sized plane.

Calvinman

Top_Gunn

My Feedback: (6)

There's a thread called "mounting servos in the wing" in the kit builders forum, with diagrams and photos. I'm too incompetent at computer stuff to give you a link, but it shouldn't be hard to find.

Calvinman

Thanks Top_Gun, I'm all over it!! : )

Calvi