Hi guys
I just realised that the fact that the outer wing spars are narrower by the
thickness of the two W.A.F's. This will account for the outer spars being
about1.3mm less in total height due to the fact that they make contact with
the skin a little further aft than the centre spars (leading edge of spar).I
know I could just trim off 2.5mm from the top and bottom of the spar but am
conserned with how close the waf attach bolts will come to the edge.I have
also worked out that if I move the airfoil back about 28mm relative to the
spars, they will fit perfectly. Of course the C of G will move back by the
same amount.The way I see it, this solution has more advantages than
disadvantages: 1: I end up with a spar that is stronger by a long way over
the standard RAF 48 spar due to two factors namely they are taller by
default (18% airfoil) and slightly oversise.
2: with the C of G 28mm further back it makes getting the C of G in the
right place easier due to these planes tendency to be tail heavy.
As for the front spar, it was built with slightly deeper spar caps and can
be trimmed appropiately without ending up weaker than required.
The only possible drawback that I see is now the spar will not be positioned
over the centre of lift of the airfoil as well as before. I know VERY LITTLE
about this and for all I know it might not even be an issue at all.
Please guys, let me have any and all concerns with this remedy as I really
don't want to build a new rear centre spar.
Somebody please tell me I am stressing over nothing.
Dene Collett
South Africa
mailto: dene.coll...@telkomsa.net
P.S. Checkout www.whisperaircraft.com
