🚀 go-pugleaf

In article 727908007@spot.Colorado.EDU, johnsonc@spot.Colorado.EDU (Chris `Choke' Johnson) writes:
>I am looking for the summary of the discussion regarding what to do with
>a warped wing.  I am returning to modeling with a Sig Kadet MKII.  I
>unfortunately seemed to build a twist into the wing though.  currently,
>if the wing is flat on the table, the outside rear corner is raised by
>about .25 inches. 

Are both wings the same?  It sounds like a little built in washout.  I would
leave it alone.  If you really want to take it out, on a Kadet the covering
should be strong enough.  After you cover it, prop it up to reverse the warp
about the same amount as you have.  Then reshrink the covering and release.
It should be straight.

I usually use ammonia and water to remove warps.  This works MUCH better than
water.  Simply saturate the balsa with this solutionand clamp the wing in the
position you want it to assume.   The ammonia does something to the cells of
the balsa and causes it to be more flexable.   After it dries the water and 
ammonia are gone and the balsa resumes it's original property.   I read this
originally in one of the mags.  Maybe one of you chemical oriented guys can
expand on why this works.

I also used to steam balsa to bend it around difficult bends.  What I do for 
that is use a long piece of rubber tube, like for automobile vacuum lines, and
plug it into the wife's pressure cooker top.  Where the jiggle thing goes.  You
get great quantities of live steam in this way, so be careful.  

As far as a warped wing goes.  Don't cover it until you have the wing perfect.
Ie, both sides should be exactly the same.  If you cover it and take the warp 
by tensioning the covering, you're asking for nothing but problems and the warp
will come back forcing you to work with it before every flying session.  I have
never seen a poorly built wing fly well.  The whole difference between a great
flying model and one that's all over the sky is in building it true (and light).

I even go so far as to build my wings on a sheet of glass.   There are numerous
other techniques.  A well built airplane will groove and fly where you point it.
It will track through loops, inside and outside.  In general a great flying 
plane will make you look better than you are in the air, at least in my case it 
does.  I am currently flying 4 models.  One of them is not perfect and it is a
real bear to land as I fly it all the way into the ground.   The others are much
better and after I line up with the runway I only need to worry about the 
throttle and the elevator, not in keeping it aligned with the runway.

Just an observation, but usually the guys that are master builders (you know,
their airplanes are beautiful inside and out) have airplanes that fly as good
as they look.  I think this is because they take the care to make sure everything
is right, including the finish.  The cobbled up looking things that you wouldn't
want in your garage, usually fly crummy too.

I think there are other chemicals you can use,  someone else please??


Stan  N5CKQ

 If you mean the trailing edge of the wing near the tip is raised .25
inches...and both are the same, you have achieved "washout" which is desirable.
 If only one wing pannel is like this, get out the steam kettle and warp the
wing by hating, twisting and weighting in place till you get it strait.