ORIGINAL: SeditiousCanary
Thanks to all for responding. Let me clarify a few things.
I'll start with what I do know.
I know how far I have to throw the flaps and air brakes.
I also know the total throw can be adjusted for by which hole you mount the rod to, in addition which horn is used.
I know there are specialty servos and servos which can be modified to offer more then 180 degrees of throw.
Then there is what I don't know:
One issue is I don't know how far the servo throws.
The throw result is a mathematical formula... each linkage setup gives a different result. A typical "standard" servo using the various "arms" supplied can give from appx 3/4 inch to 2 inches of pushrod travel. Then that travel is converted back to an angular deflection of the control surface by pushing on the control horn, rotating the control surface about its hinges.
We can't specificly say... this servo gives 1 inch of travel... because you can change how much it gives just by changing which hole you use.
Another other issue is I am trying to design the linkage to match the throw of the servo (again, because 100% throw is better for the servo and easier to set up as someone pointed out).
You adjust which holes are used on the servo and on the control horn to achieve the desired throw angle for the control surface being moved. In some cases you use a hole very close to the center of rotation of the servo output shaft and one far out on the thing being controlled (use this for the nosewheel on a trcycle landding gear airccraft) Sometines we use one far out on the servo and close in on the control surface (ailerons on a Fun-Fly airplane so you can do CRAZY maneuvers) Sometimes we try to match the distance from center at the servo to the distance from hinge at the control surface (most surfaces on a typical sport aerobatic model, like a Four-Star-40... at least till you get used to it...)
I have a few minor details I'm still working out about where various pivot points and tracks will be placed in the wing, but my main issue is designing the linkages without knowing dimensional data more about servos. I was guessing that most servos throw is 120 degrees since (as someone pointed out) speeds are given for 60 degrees, it would be logical to assume this is a center point, with 60 degrees on either side. From the limited amount of R/C experience I have, it seemed highly unlikely there would only be a total of 60 degrees of throw. Horns are another issue. It kills me that not one servo website I have been to talks about where the holes on the various horns they make are located. This seems to be The Most Fundamental Of Information when it comes to selecting a horn. Overall size is nice to plan internal clearance, but not that helpful to me in this case.
The issue of control horn and servo arm selection is left to the modeler. (sometimes not the greatest idea...) but you get a plastc bag with about 4 to 6 servo arms with a typical servo. These arms are sized appropriate to typical uses of the servo they come with. The control horns shipped with a typical model will be apporpriate, assuming you use the correct size servo (and servo arm) and you use the kit maker's recommended engine size. (a whole bunch of IF's... and they are often not followed.)
If you build from some good quaility kits and follow the recommendations in the kits, you will get a feel for what is correct. Unfortunately i don't know a good way to explain what is appropriate when in the space that would fit in this discussion forum. (the amount of servos, optional arms, servo horns, and different aircraft is HUGE!)