AutoCAD Civil 3D General Discussion

AutoCAD Civil 3D General Discussion

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Active Member
agreement
Posts: 7
Registered: ‎08-04-2011
Message 1 of 12 (960 Views)

Civil 3D model scale issue

960 Views, 11 Replies
12-10-2012 07:43 AM

I've been learning this program and believe it's the best program to use for modeling future underground utilities on the project I'm on. I've been able to create new pipe sizes and materials and have been able to set inverts and rim elevations, but I realized that it's not modeling the diameter of the pipes correctly. I'm in the proper units and my lengths dimesion properly, but say if I select a 48" HDPE pipe to be drawn, when it's modeled I can measure the diameter and it says 4.25". So, it's converting almost every 12" to 1". A 4" iron pipe models as 3/8" diameter. I've played with multiple new files and units, but can't seem to get it to model at the true diameter. Even if I scale the drawing it does not scale the diameter, only length. Is there something simple I'm missing? Thanks for any help.

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tcorey
Posts: 2,649
Registered: ‎12-18-2002
Message 2 of 12 (935 Views)

Re: Civil 3D model scale issue

12-10-2012 10:53 AM in reply to: agreement

Hello,

 

What command are you using to query the diameter? What view are you in? Feel free to post a drawing.

 

Tim

 

 

 

    

Tim Corey, Owner
Delta Engineering Systems
Redding, CA
Autodesk Authorized Value-Added Reseller
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AllenJessup
Posts: 6,023
Registered: ‎05-21-2003
Message 3 of 12 (930 Views)

Re: Civil 3D model scale issue

12-10-2012 11:03 AM in reply to: agreement

It sounds like you have your units set incorrectly. Civil 3D can only be run in 2 systems. A foot based system or a Meter based system. If units are set to Architectural. Things will not work right. Also do not use the Units command to control this.

 

Go to the Toolspace and move to the Settings Tab. Right click on the active drawing and select Edit Drawing Settings. In the Drawing Settings dialog box, go to the Units and Zone tab. Below is my drawing settings for a Foot based drawing at a 40' scale in State Plane coordinates.

 

s1.PNG

 

Try THIS link.

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agreement
Posts: 7
Registered: ‎08-04-2011
Message 4 of 12 (915 Views)

Re: Civil 3D model scale issue

12-10-2012 01:54 PM in reply to: tcorey

I'm just using the distance command to measure the diameter. It will measure the same whether I'm in 3D, plan, or elevation. No matter what units I'm set at it won't model the actual diameter. I need them to model as the actual diameter so I can bring into a master file in navisworks for clash detection and coordination. Does Civil just not model the actual size since it's more of an engineering tool?

Active Member
agreement
Posts: 7
Registered: ‎08-04-2011
Message 5 of 12 (914 Views)

Re: Civil 3D model scale issue

12-10-2012 02:00 PM in reply to: AllenJessup

I opened a new file and didn't mess with the units except for the screenshot you posted below, which I've been in before and set up almost the way you have it. I copied what you had and did the same process and if I model a 12" concrete pipe the diameter will measure as 0.4000 (since I'm in Decimal). If I change it to Architectural it measures as 3/8", which obviously are both the same measuremant. Does Civil just not model actual diamters? As I posted in the other reply I need it to actual model a 12" diameter pipe so I can bring into a main file in Navisworks to test for clash detection and construction coordination.

The only way I have found to model actual diameters is to sweep a circle that I make at a 12" diameter with my line. This method isn't as efficient and accurate when needing to set rim and invert elevations.

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BrianHailey
Posts: 2,828
Registered: ‎04-27-2005
Message 6 of 12 (906 Views)

Re: Civil 3D model scale issue

12-10-2012 02:07 PM in reply to: agreement

Civil 3D most definitely models the actual diameter. As others have stated, you are having a units issue. Try this, create a new drawing using the provided .dwt that comes with Civil 3D and create a pipe. Now go measure the pipe. You'll see it is the actual size you specified.

 

Another thing, make sure you measuring the inside diameter as a pipe can display just the outside of the pipe, just the inside of the pipe, or both (depending on the style assigned to the pipe).

 

CLICK HERE FOR IMAGE

Brian Hailey
CAD-1.com
My Blog
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agreement
Posts: 7
Registered: ‎08-04-2011
Message 7 of 12 (890 Views)

Re: Civil 3D model scale issue

12-10-2012 02:57 PM in reply to: BrianHailey

Correction to my last two replies. Sorry, I meant to say that a 4" Pipe will measure as 0.4000 (Decimal) or 3/8" (Architectural) and a 12" Pipe will measure as 1.3333 (Decimal) or 1-5/16" (Architectural).

 

I opened Civil, selected new drawing, drew a line, create pipe network from object, select 12" concrete pipe, and then measure the diamter and get the dimensions I typed above for a 12" pipe.

 

In your attached image it says 2.0000 for the dimension, isn't that saying it's 2". If you change units to Architectural it should dimension as 2". I did a test with exporting this to Navisworks, or any other program that can read 3D models, imported it, measured, and still a 12" pipe made in civil measures as 1-5/16".  

 

The outer diameter is displayed and is set at 12", which is default to Civil 3D. My file is attached.

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BrianHailey
Posts: 2,828
Registered: ‎04-27-2005
Message 8 of 12 (883 Views)

Re: Civil 3D model scale issue

12-10-2012 03:19 PM in reply to: agreement

As mentioned before, Civil 3D will not work in units of inches. The drawing is in feet. Your pipe is a 12" pipe - which is a 1' pipe. If I measure the inside diameter of your pipe, you'll see it is 1 unit wide (which is 1'). HERE

 

When you are in a 3D view, you are seeing the outside of the pipe. Remember, pipes have a wall thickness. Your pipe has a wall thickness of 2" (HERE) for a total outside diameter of 12"+2"+2" or 16" or 1' 4" or 1.3333' HERE

 

When I take your drawing into Navisworks, the pipe shows up as 1.33 ft. HERE

 

Never ever ever ever never ever never ever ever ever never set your drawing units in Civil 3D to Architectural. Architectural units ONLY work when the drawing units are set to inches and Civil 3D should NEVER have drawing units set to inches. HERE

Brian Hailey
CAD-1.com
My Blog
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Neilw
Posts: 2,302
Registered: ‎09-04-2006
Message 9 of 12 (874 Views)

Re: Civil 3D model scale issue

12-10-2012 03:33 PM in reply to: agreement

I concur with Brian. The pipe has the correct dimensions when measured using the Distance command.

 

Remember that Autocad files do not know what a unit represents. You must assign what a unit represents in the DWG settings with the units command. When you assign Architectural units to a dwg, a unit is interpreted as 1 inch.  When you assign Decimal units to a dwg, a unit is interpreted as 1 foot (or 1 meter in a metric project). Civil 3D tools require units to be set to decimal. It always interprets a unit=1 foot (or 1 meter in a metric C3D project).

 

So when you measure a 12" diameter pipe with units=decimal, it will measure 1.0 units. Now if you look at the Civil 3D pipe properties it reports the pipe is 12" diameter and 2" wall thickness. Those units are coming from the pipe part attributes, not the Autocad units. That is probably where you are getting confused.

Neil Wilson (a.k.a. neilw)
Infrastructure Suite/C3D 2013, LDT 2004, Power Civil v8i SS1
WIN 7 64 PRO
HP Pavillion h8xt, i7 2600, 12 GB
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AllenJessup
Posts: 6,023
Registered: ‎05-21-2003
Message 10 of 12 (848 Views)

Re: Civil 3D model scale issue

12-11-2012 05:54 AM in reply to: agreement

I looks like others have covered this issue while I was off. Hopefully their advise will have solved your problem.

 

Allen

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