problem with CAD link - it shows up HUGE!!!

[patricks]

I'm having a problem with a linked CAD survey. I was working on a project this afternoon, had linked in the CAD survey, rotated it and moved it down to the correct position, and acquired coordinates. Now when I opened the file this evening, suddenly the CAD file appeared to have rotated back the same amount as my angle of project north from true north. However the kicker is that the outline for the CAD file is MASSIVE, like 800 hundred MILES long! The CAD geometry itself is still at the correct scale, though, but way down in the very corner of the linked import instance outline.

I opened the survey in AutoCAD, turned on everything, and did not find any extraneous items. I even deleted a few items, and saved a copy of the file.

If I start a new project, I can link in either the original or the copy of the CAD file and it comes in correctly. But then if I go back to my project file, and link in either the original OR the copy of the file, once again it comes in at the correct scale, but the outline is absolutely ginormous! Another thing that's odd is that it doesn't give me the normal "2-mile across" error normally associated with huge CAD files.

Why would this CAD file have a problem like this in only one Revit file? And why did it suddenly happen between this afternoon and this evening? No one else has been in or worked on either the Revit file or the CAD file.

*edit* well I tried resetting everything in the project base point back to zero. The X, Y, and Z values were only a few hundred feet from zero, but the rotation was something like 201 degrees (building was drawn with entrance down, but now that we have site info, entrance will be facing somewhat northeast, so north will be down on the drawings). Project North still faces up. When I reset everything back to zero, the CAD file linked in correctly.

[patricks]

The CAD file was just barely inside the 2 mile diameter limit. I tried deleting some stuff, bringing it down to about 2000 ft. across. Still get the same problem, after getting the survey in the right location, getting True North and Elevation of the project base point correct, and then saving the position of the survey back to the CAD file. After I close the file and then re-open, the CAD geometry is rotated (still the correct scale) such that the survey appears in the Project North orientation, even though the Revit view is oriented to True North, and the outline around the CAD file becomes massive.

Should I just live with not having the survey's location shared within the project?

[patricks]

The problem must be the Revit file.

I tried starting a new file, linking in the survey, rotating and acquiring coordinates, save and close, reopen and it was just fine.

Then I tried linking in my building to that new file, and publishing coordinates to the Revit link. So I did that, saved and closed (and saved locations in the Revit link), then opened the building file and tried to bring in the survey by shared coordinates. This time the survey outline was hundreds of miles long immediately when it linked in, with the geometry way off in space.

Something must be wrong with this particular Revit file to be affecting the CAD file in this way.

[dhurtubise]

Did you tried specifying coords instead of acquiring?

[patricks]

hmmm nope... not sure what coordinates I should specify. Do I specify coordinates at a point of the Revit model, or at a point of the linked survey?

[dhurtubise]

Pick a point on the AutoCAD file were you know the exact coords.

[patricks]

I've decided to just keep the survey unshared. There are no other new buildings on this site and no one really has any need to use the coordinate system of the survey.

But still, I'd like to figure out what was happening when I did acquire coordinates and share the location of the survey.

[dhurtubise]

Can you post the AutoCAD file?

[patricks]

not sure if posting it to public domain would violate any agreements with us and the surveyor....