Proper scale

[Yellowstone Construction]

A few weeks ago I sent my engineer an dxf export of a drawing for him to use in Revit. He said , he had difficulties in reviewing and separating the layers. He had to do most of the work in AutoCad. He asked me "What scale I had drawn it in which was 1:48. He told me all of my drawings need to be 1:1 and that this would help him redraw my exports. He says that this is the standard for CAD files. I have always used 1:48. Most of my set-ups all start out in 1:48. So is 1:1 the accepted way to scale drawings or is this an AutoCad requirement?

[Petri]

The layer scale you use in VW has no effect in AutoCAD export. Unless you actually scale objects, you always work in 1:1 scale in VW.

I have exported hundreds of VW documents to AutoCAD and never had this problem.

[P Retondo]

Malin, don't export to AutoCAD using .dxf, use .dwg.

AutoCAD doesn't keep track of "reality" the way VW does, so for the ACAD user the setting for units makes a difference in how the program interprets the "size" of an object. I often encounter the need to scale a drawing by a factor of 12 or 1/12 because ACAD is interpreting inches as feet, or vice versa. This is particularly an issue between Architects and Civil Engineers. Keep trying and you and your AutoCAD colleague will get the hang of it. And have patience with the AutoCAD lack of clarity about scale and units and the notion of 1:1. 1:1 means something technically different in AutoCAD than it does in ordinary parlance; setting the various "scales" in AutoCAD is a big issue, while it is not such a big deal in VW.

If you are working to please the AutoCAD user, set up your layering scheme the way he or she does. VW can work perfectly well using those organizational conventions. It probably won't make much sense, but much of the AutoCAD way of doing things has evolved through a very tortured process.

[ 11-12-2003, 01:02 AM: Message edited by: P Retondo ]

[jfmarch]

our experience is the same as petri's above- we have not had problems with others using our DWG exports. i used to work in autocad and both ac and vw are setup in similar ways in that you draw everything at full size (1:1). how the program's scale the information is different.

what we do when we export is to export as LAYERS, which seems to aid our consultants in sorting through the info. we never export DWF files, they are too big for the effort.

[jfmarch]

yes, that's right. i meant DXF not DWF....

thanks

[MikeN]

The guy is using Revit for cryin' out loud. 'nuf said.

[P Retondo]

Jim, I think you meant DXF, not DWF.

Here's an interesting fact about AutoCAD that shows it handles "1:1" differently from VW. If you draw a 25.4mm x 25.4 mm square in VW, then change your units to inches, you will find it measures 1" x 1". Do the same thing in AutoCAD, and you will find that your square now measures 25.4" x 25.4".

I just reviewed a set of AutoCAD shop drawings drawn primarily in millimeters. Off to the side in model space there was a little dense square of information. That turned out to be the "inches" version of the same drawing, which was a copy scaled down by a factor of 1/25.4. So much for 1:1 reality in ACAD.

In my experience, if both the VW and ACAD users are using Architectural units, the translations back and forth will work well. If they are using different units, respectively, the translations will need to be scaled.

[ 11-12-2003, 12:53 PM: Message edited by: P Retondo ]