Help with both AutoCAD and Revit

[patricks]

I'm trying to figure out this issue with these site surveys and how they come into Revit.

Could someone please take a look at these 2 survey files and tell me what the difference is regarding the 0 elevation? In both files, annotations etc. are at elevation 0, while the contour lines are up at their respective elevations. However, when I link both files into Revit, the Isle file comes in with the annotations at 98.xxx' below Revit's 0 elevation, while the survey.dwg file comes in correct with annotations at Revit's 0, and the contours at the correct height.

Could it have something to do with differences in UCS between the files or something? Something in the Isle file has to be telling it that the actual 0 elevation is 98.xxx feet above where the file says 0 elevation is located.

I have attached both CAD survey files, as well as a Revit file with both CAD files linked in. If you download the files and update the file locations in Revit, you should see how they're not coming in at the same level. The attached image shows the survey.dwg link on the left, coming in correctly with its annotation that reports 0 elevation actually at Revit's 0 elevation. The link on the right shows the Isle Topo file with annotation that reports 0 elevation at some random dimension below Revit's 0 elevation. This throws off all the contour elevations by that value.

[dgreen.49364]

Patrick, Here is what I noticed.

When I opened the survey file and selected the contours they were not at the correct height, by a factor of 12. Units were set to architectural. When I scaled the drawing by 12, the contours all came in at the correct height.

When I opened the isle drawing, the units were decimal, which I switched to architectural. Again the drawing itself needed to be scaled up by 12 for arch units, but the contours were correct both before and after the scaling.

Not sure what all this means except that maybe your issues lies in AutoCAD units , scaling and such prior to bringing them into Revit.


...Edited...I started a new rvt file and brought in the cad files after making the unit/scaling adjustments and everything came in fine.

[ejc]

Are you using "Auto Detect" or specifing the units?

I would "specify" each imports units (each file could be diff. as mentioned above).

Let us know!

ejc

[patricks]

I had to specify the units as "Feet" for BOTH files. If not, they would come in 1/12th the correct size. Yet Survey.dwg was coming in correctly despite having to be scaled.

How do I go about checking units and things like that in those CAD files?

[STHRevit]

We always have this issue over here in Australia.

We always check the cad file first as we normally have to scale it up by 1000. For some reason surveyors over here like to draw at 1/1000th scale.

We prefer to adjust the cad file to 1/1 prior to linking, just to reduce the possibility of Revit having an issue with the linked file.

[patricks]

Now what about this file? This is another one we were having trouble with.

I checked the units and they were set to decimal feet, and everything appeared to be the correct scale, even when linking into Revit with Auto-Detect set for the units. However it comes in 302.38 feet below Revit's 0 elevation.

I tried changing the units to Architectural Inches, and everything still looked correct, contour lines still report the correct elevation. But it still comes in 302.38 feet below Revit's 0 elevation. So that puts the 250' contour, for example, at -52.38 feet below the 0 elevation in Revit.

WAIT - the problem was the file was located over a mile from the origin. I grabbed everything and moved it near the CAD origin and suddenly it links into Revit just fine, everything at the correct elevation. :mrgreen: