If the wing and stab incidence are off on an already built plane, what options are there to correcting this? Wing is removable so I imagine you could add shims but stab is fixed (epoxied) into place and would require major surgery (out of my ability to do neatly)? Any help appreciated.

- Joe

if stab is already glued, then wing is your only answer, depending on which plane type you are talking about the fix could be easy or not, also if is a trainer or wwi plane 1/2 degree is not that bad however pattern or serious arobatic type plane need to be right on the money.-
What plane are you trying to correct??

It's a Sig Cap 231EX. I still need to check the incidence, but I have to order a meter first, unless there's another way to do it without the special meter. It's a low wing so perhaps the lower wing will be easier to adjust?

Sig kits have the stab and wing 's mounted where there supposed to be. What make's you feel there incorrect?Buz^

Greetings!

I have a "favorite way" to change the incidence. After determining which way and how much to go, this method will give you a new and solid wing saddle, but in a slightly different position relative to the stab.

First, make a couple of shims from a balsa stick that will prop the wing up to where you want it, and tack the shims in place on the fuselage with CA. Then cover the wing with Handi Wrap (thin plastic film) and bolt it into place. Then mix up a batch of 30 min epoxy and micro balloons, about 50% each. Fill the gap between the wing and the fuse with the mixture and smooth it into a fillet with your finger. When dry, pop the wing off and sand the rough edges of your new wing saddle to shape. Works great!

Ernie

Care should be taken here, most people are not aware that there is a difference between decalage of the wing, and incidence of the tail. Changing the decalage will have effect on the thrust line/ datum, fuselage angle of attack, inverted flight characteristics, and sometimes ground handeling. Changing the tail incidence will correct trim.

Buz,

The Cap 231 stab sits on top of the turtle deck and can be set up wrong with out a meter.

It does not slide into a slot like some of the others do I.E. H 9 Cap.
It is real easy (without a meter) to get it off.

Well I am currently making a contraption to measure the angular relationship between the main wing and stab and will know by tonight how the two are relative to one another. I'm assuming that the correct way to fix any problem would be to modify the stabalizer and NOT the main wing, correct?

- Joe

Joe,

Your are correct, thats the way to go (fix the stab) if it is off.
You will find it easy to do.
If you do need to take the stab off, just slowly and easily remove the cover that fits over the stab and vertical stab and you will see that the horizontal stab sits on a saddle and then you can cut away the glue or better yet go get you some acetone and rub on it and slowly remove it.

Try to find a manual online...maybe Sig has one in pdf that you can download, if not, I will scan and send you what you need.

Good luck!

Cheers Robin

You are a kind sir Mr. Runyand. My contraption, and some quick trig, tells me I am dead nuts 0-0. I built a jig for both and measured the angles and there wasn't any to speak of so I'm happy now. I think I may end up spending some money on a meter anyways as I just looked online and they're not as bad as I thought they were. I already looked online for the PDf but all they have is the one you can order for $8.95 and since it was already built I didn't bother. If it isn't much trouble could you email those scans to [email protected] in case the precision meter shows any problems withmy cardboard contraption (I actually think it is very accurate but my trig is a little rusty!)

- Joe