How can i check the dihedron of my KF2 ?

[GDN]

Still searching about why i have to put a left stick constant force for not taking roll i'm going to check the dihedron of my wings.

Is anybody have a simple solution for that ?

Thanks

[Av8r3400]

Roll-trim adjustments are made at the rod-end bearings where the lift struts mate to the wings.

[GDN]

OK but how can i check the good settings ?

[Geowitz]

Easiest way is to use a "smart" level. It's usually a 4 foot long level with a digital readout. You can use a standard level with spacers as well(but not nearly as easily) if you can't get a smart level. I'm not sure what the standard angles and washout is for a model II, but you should atleast see if the wings match each other. First level the plane in all directions using the bottom of the fuse as a datum. Then place the level in the same spot on top of each wing lengthwise and see if the dihedral angle is the same on both. Then place the level chordwise undernieth each wing rib near the cockpit and make sure that is the same. Then place the level chordwise undernieth the last rib on each wing and make sure the angles match. The angle of attack of the outboard rib should be less than the inboard most rib. Probably around 1 degree less. If everything matches up you may want to look elsewhere for your problem. If you can't find the problem anywhere else it may be a warp somewhere and you can adjust the rod end bearings of the lift struts to trim the left stick force out. This would be accomplished by either raising the back left wing fitting or raising the front right wing fitting. Just make sure you preserve the washout of 1 degree(need to confirm correct washout degree though), Go 1/2 turn of the bearing at a time and try it out. It won't take much. You're basically turning your whole wing into an aileron.

[Lion8]

Is it possible to use a lazer level?

[Geowitz]

I suppose it's possible, but not realistic. I would imagine that the setup and measuring would be extremely hard to duplicate on both wings and get accurate measurements. You could probably find the dihedral, but it's the washout(twist) that would be very hard to get relative to each other.

I would think it would be easier to just use a regular 4 foot level and measure the distance to level from the surface you are checking. Basically you hold the level level and against one side of what you are measuring and then measure the distance from the object at the other end of the level. Kind of like in this picture. Here I was checking washout with the smart level, but also had a ruler on one end to measure the actual dimension of one degree of washout.

Another note - A wing with different dihedral on each side won't necessarily cause a tendency to turn. The fuse will just hang off to one side to compensate and find equilibrium.

[Dorsal]

And the wings will not line up when folded. (an easy check)

[GDN]

Sure when i unfold my right wing (to put it in flight position), i have to push up the tube to insert the cotter pin to safety it ?

So perhaps the problem is located here ?

[Dorsal]

Not likely, I think you should be looking at washout or the relative angle of atack on the outboard end of the wing. I found this was best done with a digital level as others have suggested and is adjusted with the rod ends on the lift struts.

[Geowitz]

Yeah, you really need to at least try and locate a digital level and check the washout/twist of the wing. That is the most likely cause of your issue.