forum.datacad.com

How does one dimension a curved line in DataCAD?

Thanks again,

Jack

In my experience the typical method in Architecture and Land-Planning/Surveying is to call-out the curve's properties in an adjacent note (with or without an arrow-line), rather than a graphic dimension and witness-lines. The note calls-out arc-length, arc-chord, radius and any atypical end-point conditions or alignments. Sometimes the bearing or angle of the chord is given, or the angle between the start-and-endpoint projected. <Identify> typically gives you the relevant information. Sometimes witness-lines are extending from the center-point outwards past the curve end-points is not graphically-obvious.

For really large curves like roads and railroads, there's a method used that call-out the left-right and up-down deviation at 100 feet-forwards (or meters) as a perp. distance or in arc-degrees/minutes/seconds. One arc-second is approximately one-inch of deviation at 100-yards distance in ballistics.

In mechanical drawings, it's generally assumed that the line(s) at the endpoint is tangential or perpendicular, and just the radius and center-point is typically called-out. Either as a note and arrow perp. to the curve inwards, or an arrow from the center-point outwards to the curve, and a adjacent note giving the radius. Typically the center-point is dimensionally-located or graphically obvious.