I am having a little trouble understanding the way the Arc vs Chord definition setting should work during the use of the Spiral Curve Spiral tool. Below I have 2 scenarios that report different results. I would like to know why this is happening and if there is a fix.
1. Create a Spiral Curve Spiral (SCS) between 2 tangents that are Civil elements or have Civil rules.
a. Settings->Design File-> Civil Formatting->Radius Settings - Arc Definition, 100' arc, and character set to "d"
Degree of Curvature, D = 10°.
Degree of Curvature; Arc Definition, R = 5729.578/D = 5729.578/10 = 572.9578
Invoking the SCS tool it is possible to use either value D or R within the tool to place the element into the drawing. The appropriate data is noted in the Horizontal report for the Arc definition.
b. Settings->Design File-> Civil Formatting->Radius Settings - Chord Definition, 100' arc, and character set to "d"
Degree of Curvature, D = 10°
Degree of Curvature; Chord Definition, R = 50 / (sin(D/2)) = 50 / (sin(10/2)) = 573.6857
Invoking the SCS tool for D = 10, R = 573.6857 only the R value can be entered to develop the element into the drawing. When the character "d" is used and 10 is entered for the degree of curvature the tool returns an error. When the chord definition calculated R value is entered into the spiral-curve-spiral tool, the element will be placed within the drawing.
After the element is placed into the drawing using the Chord definition, the Horizontal report displays the degree of curvature as 9° 59' 14.32". By definition it is known that the Degree of Curvature is 10° but the report is using the R value as determined by the chord definition and reporting the Degree of Curvature using the Arc definition formula. The reported value is developed as such, D = 5729.578/R = 5729.578/573.6857 = 9.987311868 decimal degrees or 9° 59' 14.32"
2 part question-
1. Why can I not enter the D value when the radius setting is set to Chord definition? Or am I missing something?
a. If the D value cannot be used with the Chord definition then how can I change the Horizontal report style sheet so that the report calculates the D value as a chord value and not the arc value?
TIA
Sean
MSV8i - 08.11.09.608 & 08.11.09.654
OpenRoads - 08.11.09.722 & 08.11.09.788