KRnetHeads,
At the Gathering, it was brought up that a downside to the "new airfoil"
is that the aileron bellcrank has to be modified (due to the thinner
airfoil cross section at the bellcrank location, I assume). One look at
that bellcrank was enough to tell me that I needed something entirely
different, so I did it my own way anyway (well documented at
http://www.n56ml.com/owings.html, but not really relevant to my point).
To me, the advantages of a wing with less drag, longer range, higher
speeds, longer glide distance, and similar stall characteristics
out-weigh the advantage of "just follow the plans" when it comes to the
bellcrank.
A lot of folks have opted for the new airfoil and managed to alter the
bellcrank to work successfully, so would those that have, please post a
link as to how they did it? This should remove any issue with building
the new wing, for those who are concerned. My guess is that the result
was simpler and more elegant than the bellcrank shown in the plans.
The old newsletters show several ways to improve on the old bellcrank,
so I'm not the first guy to think it was a bit convoluted.
Also mentioned at the gathering was that there was no real discussion of
the differences between the three versions of the airfoil, so I edited
that to point out the it's all about thickness-to-chord length ratio.
See http://www.krnet.org/as504x (near the bottom) for that, and even
more at http://www.krnet.org/as504x/templates.html .
I think it's pretty safe to say that if you are building a new KR2 or
KR2S, you should be using the new airfoil. Templates are free and
located at the bottom of the previous link. With many years of
"testing" by lots of KR pilots, it is well proven at this point.
--
Mark Langford
ML at N56ML.com
http://www.n56ml.com
