## Wednesday, November 12, 2014

### Witches Cut Plane

Going through the exercise on the this task model with an evae angle that is not at 90° for the witches cut on the valley sleeper is probably important in understanding how two canted folding planes should be intersected geometrically on the horizontal plane.

#### Kehlbohle auf unwinkligen Ground

Bernd we need rewrite this paragraph

All points found in the ground plan can now, at right angles to the axis of rotation, be folded from the ground to the valley plane. These can be angled from the intersections of the elevation line and the witches cut of the valley sleeper to the "BE or TE VS EL P" and form the starting points of the witches cut plane.

#### We/you should use the word perpendicular rather than "right angles to the axis of rotation". On the valley sleeper on the 90° eave angle, it wasn't necessary to draw the perpendicular lines from the intersection of the elevation lines in ground plan to the elevation lines in the valley plane. However, this technique of drawing the perpendicular lines from the intersection of the elevation lines in ground plan to the elevation lines in the valley plane is the only way you can correctly draw the witches cut plane.

All points found in the ground plan can now be drawn at right angles to the axis of rotation and be folded from the ground plan to the valley plane. To draw the witches cut plane, you draw lines at an right angle to the axis of rotation from the intersections of the elevation lines in the valley plane and the elevation line in ground of the valley sleeper to the "BE or TE VS EL P" .

or

All points found in the ground plan can now be drawn perpendicular to the axis of rotation and be folded from the ground plan to the valley plane.
To draw the witches cut plane, you draw perpendicular lines to the axis of rotation from the intersections of the elevation lines in the valley plane and the elevation lines in ground of the valley sleeper to the "BE or TE VS EL P" .

#### 2 comments:

1. Thanks for your post. I’ve been thinking about writing a very comparable post over the last couple of weeks, I’ll probably keep it short and sweet and link to this instead if thats cool. Thanks.
Certified Precision Roofing

2. What kind of awesome software are you using?