Roof Slope Axis Snap (Tip #2122) by E.J. Polley sets the current snap angle based on the slope of the roof you are working on. The slope information is input in imperial units as the rise per each horizontal twelve inches. For example, an entry of 4 would result in a roof sloping up (or down) four inches for every linear twelve inches. In drawing terms that equates to an angle computed by taking the arctangent of the riser value divided by twelve. Once loaded, type RS to set the roof slope snap angle. Type RS again to return the snap angle back to zero and repeat to set a different roof slope. |