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My first post - got "ruined" at Brodhead when Dale McCleskey gave me a ride inhis Piet. Never underestimate the [positive] impact of a small act of kindness!My Sonex project (scratch build #1465) is now wondering why wood and epoxy areshowing up in the shop. Not abandoning the Sonex, just figured that a littlevariety might get me through builders' block.Just starting on the Pientenpol ribs and would like some advice regarding whetherto tilt the spars 1.5 degrees forward or build them perpendicular to the chordline.I purchased Bill Rewey's 612 Riblett plott. I replotted using the original Riblettoffsets (incidentally the computer plot was identical to Bill's hand drawnlayout). When I went to lay out the spars and verticals I noticed that Bill'swere canted 1.5 degrees forward. (see attached picture - i.e. the spars arenot perpendicular to the chord line, instead they form an 88.5 degree angleto the chord line).Reading through the archives I've learned that the angle of incidence of the wingis supposed to be 2 degrees and that it is common to make the rear cabanes1" shorter to achieve the 2 degree angle of incidence.Drawing on this logic, if I build the wing as per Bill's drawing, I'd make therear cabanes 0.25" shorter to achieve the 2 degree angle of incidence (i.e. if2 degrees requires a 1" shorter rear cabane, then if the wing had 1.5 degreesbuilt in, then only 25% or 0.25" adjustment to the rear cabane is necessary.So the question: should I build the rib so the spars are: (a) perpendicular tothe chord line, (b) 88.5 degrees to the chord line, or (c) 88.0 degrees to thechord line?Here's the archive research if anyone is interested:Googled (site:forums.matronics.com pietenpol "chord line")which returned the following link:http://forums.matronics.com/viewtopic.p ... =asc&start I'm about to start cutting wood so any advice would be appreciated.Thanks,Bob JacobyJacksonville, FLBrodhead 2011Working on RibsRead this topic online here:http://forums.matronics.com/viewtopic.p ... ttachments: http://forums.matronics.com//files/rib_ ... __________