What is the best measuring technique to be assured that the wings are level and that the stab is parallel to the wings...and if the wings aren't level ( one higher than the other)what is the best way to level them out....i am asking because i have a little wattage cub that is an ARF and i can not get the wings to level out...one is about 1/8 of an inch or so higher....i measured from the tip of the wing to the back end of the fuselage to make sure the wings are centered and i got that measurement pretty much right on the money or at least i think i do...i know the measurements on a plane should be close as possible but how much error can there be before effecting the plane to the point where it won't fly...is an 1/8 of an inch a lot or what....any help would be great....thanks in advance

Don't get too concerned. On these small planes precision of flight isn't possible. Anything slightly out of true won't make much difference in the flight performance.
You can put a shim between the top of the fuselage and the bottom of the wing to raise the low side, if you want.

I use shims to get the wing on straight and then make the saddle permanent by filling it with epoxy and micro-balloons.

1/8" isn't much, but if you can make it 0 then you're better off. That slight amount may only need a piece of cardstock for a shim. This page doesn't tell you how to get the wing on straight, but it will make it stay straight after you get it that way even if you use shims like I do.

http://www.airfieldmodels.com/wing_saddles.htm

Micro balloons?

Interesting link CafeenMan. I've never heard of these micro balloons though. Do you know where they can be purchased in the U.S.?

Fever

Fever, most LHS will have them in the same area as the filers, epoxy, etc... They come in small bottles (like balsa filler) and weigh basically nothing. Just ask your LHS.

I still use a line-of-sight method to ensure stab is parallel to wing (after you first set wing correctly).

When standing behind the model, center your line of sight by looking at the fuse and making sure you can see equal amounts of the left and right sides of the fuse. Next, slowly move your head vertically up and down until you see the outside tips of the stab just begin to block your view of the wing. The points on the left and right sides of the wing where the view is blocked should be equidistant from the right and left sides of the fuse. If not, tilt stab slightly until all is equal.

This only applies to wings with dihedral. If you truly have a flat wing, then the task is even easier- just line up the edges of the wing and stab visually from the rear.

- George

thanks for all of your replies....

FlyingFever - To add to what Bear750 said, micro-balloons are sold by most hobby shops. Basically they are a very small glass bead that looks like baking soda. You can mix it with epoxy to make a paste that sands easily. It will still be harder than balsa, so you don't want to use it as a general filler. But you can vary the amount of balloons in the epoxy to get lighter, easier to sand and weaker or stronger, heavier and harder to sand.