Control surface torque question.
 

Hi guys

I am whipping together a Great PLanes Big Stik 40. I have three HS-325 standard servo's and two HS-635 high torque servo's at my disposal.

I know high torque servo's are OVERKILL on a plane like this but I might as well use them as opposed to buying new ones.

My question: Which control surface needs the most torque? I can either use the 635's on the ailerons and the 325's on the rudder elevator and throttle, or I can use the 325's on the ailerons and the 635's on elevator and rudder.

Not quite sure what the optimal choice would be here.

Marcel

RE: Control surface torque question.
 

I have Sig Kougar with Hitec 325s on the aileron, throttle, elevator and the 635 for the rudder and nose wheel. If your elevator control surface is big, I would use the 635 on it. Since one servo controls the rudder and the nose wheel I would use the 635 there as well, since it has to control two surfaces (more torque needed).

325s - ailerons, throttle
635s - rudder/nose wheel, elevator

If both ailerons are controlled by one servo I would use the 635 there instead of the elevator and put a 325 on the elevator.

RE: Control surface torque question.
 

It is similar to saying, "My right arm is stronger than my left arm, and I have to lift a pocket knife and a set of keys - which hand should I use for each?"

Either servo is going to be more than enough to do any of the jobs you're tasking them to do.

That said, if it is a tail dragger, I would use the 635's on the ailerons. If it has a nose wheel, I'd use them on rudder and elevator.

RE: Control surface torque question.
 

I know the servo's are too much, but those happen to be the only ones I have, so why not use them. Supose it would really not make a diference at the endo of the day on a 40 sized stik anyway.

Well, the Stik has one servo per aileron, and a nose wheel, so I agree what HeliTB (And you) mentioned.

The 325's on the ailerons and throttle, and the 635's on the rudder and elevator.

RE: Control surface torque question.
 

Assuming the Stick lives a long and fruitful life and who does not wish for that, does make the assumption that the flight pack components will stay in the airplane and not be robbed for the next 'Bigger & Better' which if you will admit you probably have already been thinking about.

That next 'Bigger & Better' may actually be an airplane that can benefit from the expensive servos unlike your stick that really does not care what kind of standard you stick in there. Soooo with that in mind temptation to strip your relatively new and great flying stick will be strong and you just might not get back to it, ever just because 'Oh its missing a couple of servos.

In my opinion Stripping an old airplane for a newer one is usually the death knell and it would be a lot better simply to invest in one more Hs-325 and one HS-85 for throttle and save the heavy metal for the next 'Bigger & Better', Heck you just may end up with both airplanes in commision at the same time and a choice of what to fly. Now theres a concept.

John

RE: Control surface torque question.
 

Talking abou that.

I have a Calmato. Quite a boring plane and was tempted to take those servo's out. But as you said, once you do that the plane ends up in your hanger never to fly again ... So I am keeping the servo's in there.

Would an HS-85 be enough for a 50 class engine? I have 5 lying around that I stripped from a GP Spitfire that "went down" so if I use the HS-85 for the throttle I only need 2 325's and I am set and I can keep the 635 for that "next bigger" plane :-)

RE: Control surface torque question.
 

Using a higher torque servo on the rudder/nose wheel lessens the chance of stripping the gears on a bad landing since high torque gears are stronger.

RE: Control surface torque question.
 

Yes the HS 85 is fine for throttle virtually on anything. It is what I use for all my throttles and I average about twenty five aircraft that are always ready to fly plug and play. The numbers vary slightly but that is about averge.

John