Question after import DWG from Autocad

[andreaw (andrea)]

Can you attach the file please. Also you should check your settings for “absolute tolerance” in file settings and “scale” when importing

Absolute Tolerance - Set and leave alone, and other good practices

“Absolute tolerance” is the amount of deviation from the “exact” solution Rhino will allow when a curve, edge or surface resulting from various operations cannot be modeled exactly using NURBS. For example the curve resulting from intersecting two non-planar surfaces will ususally not be exacty a NURBS curve. Rhino can create a NURBS curve which approximates the exact curve within almost any desired level of accuracy but as the maximum deviation from the exact curve is reduced the number of con…

And you can try to make a PlanarSrf then trim. Or patch. Is the curve planar?