Skewed Rafter Saw Blade Bevel Angle

The Trapezoidal Timber generated from the Roof Framing Geometry plugin based on the Skewed Rafter on page 52 in "Traité Théorique et Pratique de Charpente" by Louis Mazerolle needs a little more work before I build a full scale model. We're not suppose to cut the model with a skill saw, so there wasn't any need to develop the saw blade bevels angles. Well, it 2012 and I'm going to cut my full scale model with a skill saw, so I developed a plugin that develops the saw blade bevel angles for the skewed rafter foot and peak.


In this image I laid out  the two  "trait carré"  , drawing a perpendicular line to a given line to find the peak miter angle of 43.08446° and the bevel angle of 78.82320°.

Then I used the Tetrahedron Slice Tool to find the Saw Blade Bevel Angle 8.21141 for the cut at the peak of the skewed rafter.

For the skewed rafter foot  I laid out  the two  "trait carré"  , drawing a perpendicular line to a given line to find the foot miter angle of 43.33393° and the bevel angle of 77.79889°.

Then I used the Tetrahedron Slice Tool to find the Saw Blade Bevel Angle 8.79189° for the cut at the foot of the skewed rafter.

Here are the links to the Google SketchUp files I used in this article.

Tetrahedron_Slices.skp

Tetrahedron_Slice_1.skp

Tetrahedron_Slice_2.skp