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## Curve Calculator: Chord Definition

2 REPLIES 2
SOLVED
Message 1 of 3
1115 Views, 2 Replies

## Curve Calculator: Chord Definition

Hi All,

I have a quesiton regarding the Curve Calculator tool, and the method by which it calculates the radii given a degree of curvature as input.

The method for calculating the degree of curve that I'm utilizing is:

The issue I'm having is that I seem to be getting different results between Excel and the Curve Calculator tool in Civil 3D.

Using Excel, I have the following formula and results:

And using the Curve Calculator, this is the result:

You'll notice, the radius given by the Curve Calculator above is consistently 1/2 of the the radius calculated using Excel.  Does anyone know the formulas used by the Curve Calculator?

Command (Uppercase): TRIM, Variable (Italicized): MSLTSCALE, Civil 3D Object (Within brackets): [SITE]

Please support my Idea to revert the forum format to the old one: https://forums.autodesk.com/t5/community-ideas/revert-to-old-forum-layout/idi-p/7917987
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2 REPLIES 2
Message 2 of 3

Hello-

I think you have a slightly incorrect formula.  Civil 3D uses the following formula:

I hope this helps.

Michael M. Carlson
Senior Civil Designer

Message 3 of 3

Thanks Mike - I should have reviewed the formula rather than assuming it was correct.

Command (Uppercase): TRIM, Variable (Italicized): MSLTSCALE, Civil 3D Object (Within brackets): [SITE]