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Old 05-29-2005 | 06:55 PM
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Default RE: First Scratchbuild--need help with airfoil

Thanks Bruce:

Your idea of building all the sections together--with the phenolics and a small space between the end ribs is an excellent idea. I had not thought of doing it that way. But, I am going to follow that suggestion and build them like that.

Then--even if my phenolic isn't perfectly aligned--it won't matter. Just cut it all apart and sand the rib ends and phenolics at the saw joint. The wingtips will still fit the center section correctly.

Thats a great idea and I'm definitely going to build the wings and removable wingtips in that fashion. I'll just set the jig up and space the ribs at the joint about 1/8" apart. Run the LE stock and all the stringers, spars, TE, and phenolics right across the open space. Pull out the razor saw and cut it apart after the glue dries.

Can you tell--it's my first scratchbuild??[:-]

Thanks a bunch for all the help and good advice. I'm still torn on the cord. I want the extra sq. in. I don't know what difference 147sq.in will make. I guess I'll do the wing loading calc. with the cord as it is. My previous wing loading calcs. took into account the increased rib size at 12.25" cord.

Oh well, I'm laid-up and off work for several weeks. Back surgery. I got nothing but time and a garage full of balsa. May as well cut the new ribs. I'll never be happy if I keep the cord at 10.5" and it lands like an F-16 on a 100degree day. Then I'll just end up building ANOTHER wing and cussing myself the whole time about how I should have built it with the increased cord in the first place.

I guess that settles it.

Thanks for the help.

Maybe I'll dig this thread up in a couple months and post a few pics and give a flight report. Wish me luck![&:]