Tuesday, December 2, 2014

The eyebrow roof dormer with straight valley

Task Model
The eyebrow roof dormer with straight valley
Fledermausgaube mit gerader Kehle

Brad Morse asked me if I knew what the green lines were for in this eyebrow dormer with straight valleys and I now know the answer. The (3) green lines intersect the sloping lines of the eyebrow profile slope line and locate the perpendicular bisectors for the radius points of each of the arcs that make up each eyebrow rib. The green line to the left locates all of the radius points for the arcs on the left hand side of the rib.  The green line at the top of the drawing locates all of the radius points for the ribs on the right hand side of the drawing.

Drawing with the canted valley rafters. 

Drawing showing the inside canted valley following the arc--to level line.


  1. Sim , you may want to draw the green pulled away as in the mazerole so people can see that each arch is developed the same way but reducing

    1. Billy, I'm not sure what you mean by the green pulled away, but I added a drawing showing the arc development without the green lines. The green lines are not necessary to draw the radius points, but they're good for reference. Also, you draw the single arc and just add the V1 bevel to the drawing for the second arc. This method of drawing all the radius's is handy to know, but it would probably be easier to use storyboards and a grid layout to transfer the arcs to the timber.