AutoCAD Civil 3D General Discussion

AutoCAD Civil 3D General Discussion

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New Member
atusa60
Posts: 1
Registered: ‎07-30-2009
Message 1 of 13 (2,096 Views)

sprial curve spiral

2096 Views, 12 Replies
07-30-2009 08:21 PM
hi
im new in civil 3d.. how i can add a spiral curve spiral to two entities(not only alignments) ? would u please tell me the commands step by step?
thank u Edited by: atusa60 on Jul 31, 2009 4:32 AM
*Matt Kolberg
Message 2 of 13 (2,096 Views)

Re: sprial curve spiral

07-31-2009 07:08 AM in reply to: atusa60
You can only add these between alignment segments. You could temporarily
make an alignment, create the spiral and explode.

Curious, why woould you need a spiral that's not part of an alignmnet?

Matt
*Laurie
Message 3 of 13 (2,096 Views)

Re: sprial curve spiral

07-31-2009 02:06 PM in reply to: atusa60
Hi atusa60,

You can't draw an accurate spiral with AutoCAD, only multiple arc
polyline approximation.

Hence, if you want accurate spiral information and drafting, you have no
option but to use an alignment.

If you can accept the approximation, Mark has told you how to do it.

Regards,


Laurie Comerford


atusa60 wrote:
> hi
> im new in civil 3d.. how i can add a spiral curve spiral to two entities(not only alignments) ? would u please tell me the commands step by step?
> thank u
>
> Edited by: atusa60 on Jul 31, 2009 4:32 AM
*Matt Kolberg
Message 4 of 13 (2,096 Views)

Re: sprial curve spiral

08-02-2009 05:57 PM in reply to: atusa60
Who's Mark?
*Laurie
Message 5 of 13 (2,096 Views)

Re: sprial curve spiral

08-03-2009 02:41 PM in reply to: atusa60
Hi Matt,


Oops! Sorry Matt. I didn't have my glasses on and misread your name.

Regards,


Laurie Comerford


Matt Kolberg wrote:
> Who's Mark?
Member
GeoTechnical
Posts: 4
Registered: ‎05-13-2010
Message 6 of 13 (1,986 Views)

Re: spiral curve spiral

05-18-2011 10:59 AM in reply to: atusa60

I have to enter deed information and some times along highways and railroads the boundary is a spiral curve. In LDD 2004 this was a command with in the lines and curves menu.

GeoTechnical
Land Surveyor
Gillette WY
Contributor
Justin_az282
Posts: 18
Registered: ‎01-18-2012
Message 7 of 13 (1,821 Views)

Re: spiral curve spiral

03-05-2012 12:00 PM in reply to: GeoTechnical

Any ideas of how to fake it in from just a back tangent, a delta, a length and whatever A=1/2 means? I dont have a PI or anything to tie in the begin curve so I need to figure the end of the spiral some how. Anybody?

Contributor
Justin_az282
Posts: 18
Registered: ‎01-18-2012
Message 8 of 13 (1,816 Views)

Re: spiral curve spiral

03-05-2012 12:16 PM in reply to: Justin_az282

"A" equals the deflection angle off tangent from TS to SC. FYI

*Expert Elite*
sboon
Posts: 2,112
Registered: ‎11-08-2005
Message 9 of 13 (1,799 Views)

Re: spiral curve spiral

03-05-2012 04:17 PM in reply to: GeoTechnical

Are you sure that the spirals you're entering are clothoid type?  Civil3d only uses clothoid but many old railway and highway designs used other spiral definitions.

*Expert Elite*
BrianHailey
Posts: 2,792
Registered: ‎04-27-2005
Message 10 of 13 (1,791 Views)

Re: spiral curve spiral

03-05-2012 08:15 PM in reply to: sboon

SBoon wrote:

Are you sure that the spirals you're entering are clothoid type?  Civil3d only uses clothoid but many old railway and highway designs used other spiral definitions.


I'm pretty sure Civil 3D can use other types of spirals. If you go into the "Curve and Spiral Settings" on the create alignments toolbar, there is an option to change the spiral type (at least I'm pretty sure that's what that setting is for, unless there are other types of curves).

Brian Hailey
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