Windsor Chair Compound Angle Calculator

This calculator was designed to calculate drilling angles for legs and spindles on Windsor chairs. Given rake and splay angles taken from front and side view of a measured drawing, this form calculates the angle of incidence of the drill bit, and the angle of the sight line which the drill bit will be perpendicular to.

If you don't know what I'm talking about, this form might not do what you want it to.

For the front and side angles, specify an obtuse angle in degrees, using the seat as the reference axis. For example: 105 degrees would not be an unusual side/front angle.
Angle, front view:
Angle, side view: (If you're using the seat rise angle, use positive values for the front leg, and negative for the rear leg.)
Rise angle, side view: (To raise the seat, use a negative angle.)

Without Rise

Incident angle: 69.2464290163147
Sight angle, wrt front line: 45 (225)

With Rise

Incident angle: 69.2464290163147
Sight angle, wrt front line: -135 (45)