Hi,
I am having some trouble obtaining the correct amount of aileron throw on my Nexstar. The instruction manual calls for 1/2" up and 3/8" down and the wing only houses a single servo for aileron control. I can't seem to configure the linkages/clevises to deliver the correct amount of throw to both ailerons in both directions. Any advice would be greatly appreciated.

I can see how creating the aileron differential with dual aileron servos would be easy....

Thanks!

To create alieron differential on a single servo you need a wheel instead of a dual arm. The holes for the linkages are made foward of the center of the wheel. I can't think exactally how to draw this.... Instead of making the holds directly across from each other and across from teh center of the wheel, the holes are made across from each other and foward of the center of the wheel.

So instead of this:

0 X 0


Where the 0's are the linkage holes and teh 'x' is the center of the wheel,

You get this:


0 0
X

This gives you differential travel

Unfortunately... the autoformatting made the diagram a bit off...

. 0 X 0

Vs

..0...0
....X

If the pushrods are on the bottom of the wing... the offset is forward, so that push has more effect than pull. If the pushrods are on the top of the wing as in the 4*40 then the offset is to the rear so that pull is more efective.

please excuse the crude drawing ...

This should make it a little clearer...

PS, Don't worry about getting the "1/2 Up x 3/8 Down" Exact. As long as you have aproximately 1/2" up and you have more up than down, you'll be fine

You guys and your graphics skills!


Andy

One Picture is worth a thousand words. (But takes up more memory on your computer)

When I grow up I want to be just like MinnFlyer

Another way to get differential on wings that use torque rods (as most trainers do) is to bend the arms that come up out of the wing. By default, they are at 90degrees to the aileron, but if you bend them forwards on a high-wing model, you get more up than down travel.

The red line is the origional 90deg. torque rod.

The two blue lines show what I mean by bending it forwards. The more forward you bend it, the more differential you get.

Thanks soo much for all the help! It totally makes sense. Guess i wasn't seeing the big picture.

Be careful bending the torque rod with it pre-installed... use the method with the extra "dogleg" and HOLD THE ROD while bending the end.

Trying to twist the rod between the 2 original beds can work ifyou have not assembled the model (as in the torque rod is not in the wing at all) but doing that with it in the model, you are likely to break somehting.

FHHuber,
You are right on about the bending. I usually use the dogleg approach, since it's easy to do and you can tweak the amount of bend to adjust how much differential you want. Grabing the aileron and trying to bend the rod will almost certainly tear the metal rod out of the wooden aileron, or at least loosen up the hole creating a lot of slop in the linkage.

This is interesting stuff.
I didn't know this!
THanks

Geistware didn't know something?
I am not being a smart *****, I am genuinely surprised. You are a great help to so many of us!!! Please continue!!!

Now, what is the dogleg approach? I need to bend a rod back to straight.

Thanks,
KW_Counter

If you look at the picture I posted above, the light blue line would be the dogleg version. The aileron torque rod usually comes from the factory bent at a 90degree angle. If the plane is an ARF, it's often pre-installed. If you want differntial, bend the exposed rod to match the light blue line. The red line is how it comes from the factory. If you can bend it before installation, the dark blue line would be the way to go, a straight rod, just angled forwards.

If you bent the torque rod before it was in the model and didn't use the dogleg... its fine, don't change it.

The place that NOT using the dogleg can be a problem is when putting it into a model that was flying (or flyable) and you wanted to change the differential using the bet torque rod method. The dogleg helps prevent you from damaging the model when changing the torque rod angles.

If it ain't broke... don't fix it.