How to draw Reverse Horizontal curve

[Anonymous]

Dear members,

           I have difficulty while drawing Reverse Horizontal curves between tangents. I have marked points with circle...Please help me...thank you... 

[Anonymous]

Dear members,

           I have difficulty while drawing Reverse Horizontal curves between tangents. I have marked points with circle...Please help me...thank you... 

[wfberry]

I think you must enter a very short tangent between curves to get this to work.

Bill

[wfberry]

I think you must enter a very short tangent between curves to get this to work.

Bill

[wfberry]

Perhaps I answered too quick.

I just drew one with lines and circles (arcs) and converted it to a polyline then converted to an alignment.  It even labeled the PRC as such.  The method I used was going back to my geometry days and making sure that I was drawing tangents, etc.

However, if you need to modify the alignment it does not appear to maintain its' tangency.

Bill

[wfberry]

Perhaps I answered too quick.

I just drew one with lines and circles (arcs) and converted it to a polyline then converted to an alignment.  It even labeled the PRC as such.  The method I used was going back to my geometry days and making sure that I was drawing tangents, etc.

However, if you need to modify the alignment it does not appear to maintain its' tangency.

Bill

[AllenJessup]

I always draw with lines and arcs first. Remember. You can draw a line. Then start the Arc command and hit enter for the first point. That will start an arc that is automatically tangent to the line you just drew. It works the other way too. Draw the arc first and the start the line with enter for the first point.

Allen

[AllenJessup]

I always draw with lines and arcs first. Remember. You can draw a line. Then start the Arc command and hit enter for the first point. That will start an arc that is automatically tangent to the line you just drew. It works the other way too. Draw the arc first and the start the line with enter for the first point.

Allen

[Anonymous]

I've been using AutoCAD for over 15 years and thought I knew most tips and tricks, but somehow I never noticed that one Allen. I guess the old adage about learning something new every day is true.

#

[Anonymous]

I've been using AutoCAD for over 15 years and thought I knew most tips and tricks, but somehow I never noticed that one Allen. I guess the old adage about learning something new every day is true.

#

[tcorey]

The same functionality works with polylines. Draw the line segments, press A for arc segment and it is automatically tangent. Press L for line segment, it's not automatically tangent, but press L again, for Length of segment, and it makes the line segment tangent to the arc segment.

[tcorey]

The same functionality works with polylines. Draw the line segments, press A for arc segment and it is automatically tangent. Press L for line segment, it's not automatically tangent, but press L again, for Length of segment, and it makes the line segment tangent to the arc segment.

[AllenJessup]

That's why I like to point it out every once in a while. It's always been there since AutoCAD's first release. Of course I had to learn it at one point myself so I could pass it on.

Allen

[AllenJessup]

That's why I like to point it out every once in a while. It's always been there since AutoCAD's first release. Of course I had to learn it at one point myself so I could pass it on.

Allen

[AllenJessup]

Back to your original post. If you have the alignment shown already created. Using Floating Curve (From entity, through point, direction at point) might work. Specify the pass through point as the midpoint where the reverse curves would meet and specify the tangent direction (you'll have to draw that first. Do that from the end of both tangents to remain. This is theory. I havn't done it myself.

See http://docs.autodesk.com/CIV3D/2014/ENU/index.html?url=filesCUG/GUID-AA6AA63A-9BE3-41BD-8FA7-BFE8245...

Allen

[AllenJessup]

Back to your original post. If you have the alignment shown already created. Using Floating Curve (From entity, through point, direction at point) might work. Specify the pass through point as the midpoint where the reverse curves would meet and specify the tangent direction (you'll have to draw that first. Do that from the end of both tangents to remain. This is theory. I havn't done it myself.

See http://docs.autodesk.com/CIV3D/2014/ENU/index.html?url=filesCUG/GUID-AA6AA63A-9BE3-41BD-8FA7-BFE8245...

Allen