This rafter calculator app is for the WorldSkills Carpentry Competition training or use to verify the art of carpentry. With this app the carpenter can verify their geometric layout method while using the traditional layout geometry. It has seat lip cut (claw) angles at the hip rafter for all of different types of rotated rafters as well as Hexenschnitt Gratsparren. Coupe de pied de noue, avec dévers inegaux.

All bevel angles are referenced from the traditional layout methods used by the French and Germans carpenters. Use with the French Rabattement de Surface method (folding roof surface) or the German Flachenklappung method. Basiswissen Schiften or Charpente Les Traces. Use with Traité Théorique et Pratique de Charpente by Louis Mazerolle or Handbuch der Schiftungen by Manfred Euchner or Draw Down Technique --> Abklappung

Jack Rafter Plumb To Earth Perpendicular To Plate Line Bevel Angles, with claw angle.
Jack Rafter Plumb To Earth Offset/Skewed From Plate Line Bevel Angles.
Jack Rafter Plumb To Roof Surface Offset/Skewed From Plate Line Bevel Angles, with claw angle.
Rafter Plumb To Earth Offset/Skewed From Plate Line Bevel Angles.
Crossing Jack Rafters Plumb To Roof Surface Bevel Angles, with claw angle.
Saint Andre Cross Rafters Plumb To Roof Surface Bevel Angles, with claw angle.
Purlin Rafter Plumb To Roof Surface Bevel Angles, with claw angle.
Witches Cut on Hip Rafter with Square Tail Rafters
Hip Rafter Edge Bevel Angles, Backing Angles
Devers De Pas for Rafters Plumb To Roof Surface and Offset/Skewed From Plate Line
Claw Line Dimensions for Drawdown Layout method
Tréteaux Angles

Traditional French and German Roof Framing Geometry Layout Books
Developing a construction plan in which each piece of wood can be found in its true shape for
Oblique rafters, Slanted Rafters, Skewed Rafters, Canted Rafters
http://sbebuilders.blogspot.com/2013/04/traditional-layout-books.html

Google Sketchup Model of Traditional Roof Framing Geometry Layout Techniques 1
http://sketchup.google.com/3dwarehouse/details?mid=2d015744fa1d0f02d1f8ef2a7a594c76