Slightly Off Axis

[sthedens]

I've been pulled into Revit support on a project to address the growing list of warning errors. There are hundreds of "slightly off axis" lines. Some of these are legitimate as they were traced from an AutoCAD linked site plan. However, we have a number of drafting views where if we draw a 45 degree line (not tracing or snapping to anything) we get the slightly off axis warning. Any ideas on what could cause this and how to correct it?

[patricks]

Although drafting views *shouldn't* have any relation to model settings, it may be related to project location and rotation from true north. Check Manage > Location > Site and check the angle from true north. I seem to recall a project that was just a fraction of a degree from 45 degrees from true north, and I got tons of off axis errors in only the north/south views, but I think I may have gotten them in drafting views as well.

[Phil Read]

I doubt the lines in ACAD weren't traced - more likely they were picked. And the "...slightly off axis..." warning would have popped up as those off axis lines were picked. All those warnings continue to exist in the database.
My .02 is that you're in a world of hurt. There's no way to automatically fix this. And as a result, room areas (schedules) and sections are going to be slightly off. Documentation is going to be a PITA as dimensions that would normally work between parallel elements don't work between elements that are slightly off axis (and as a result - not parallel).
Stupid with a hammer (CAD) is dangerous with a nail gun (BIM).
Suggest being very careful when picking CAD lines to create BIM models - and definitely stop and ask a few questions if the "off axis" warning" pops up. Trace walls clean in Revit. Use the CAD lines as a guide and little more. Or you'll end up recreating errors.
-Phil

[patricks]

I doubt the lines in ACAD weren't traced - more likely they were picked. And the "...slightly off axis..." warning would have popped up as those off axis lines were picked. All those warnings continue to exist in the database.
My .02 is that you're in a world of hurt. There's no way to automatically fix this. And as a result, room areas (schedules) and sections are going to be slightly off. Documentation is going to be a PITA as dimensions that would normally work between parallel elements don't work between elements that are slightly off axis (and as a result - not parallel).
Stupid with a hammer (CAD) is dangerous with a nail gun (BIM).
Suggest being very careful when picking CAD lines to create BIM models - and definitely stop and ask a few questions if the "off axis" warning" pops up. Trace walls clean in Revit. Use the CAD lines as a guide and little more. Or you'll end up recreating errors.
-Phil

Steve was saying that when they simply draw a line at a 45 degree angle in a drafting view, not tracing or snapping (just using the default 45-deg. snap I assume) they get a slightly off axis warning. Why would that happen?

[DaveP]

I've seen that happen when the VIEW (Elevation or Section) is "slightly off axis"
Once the View itself is a bit crooked, it seems like nothing else lines up, either.
Recreating the View fixed it for us, but we were lucky and only had three or four Views to fix.