Sweep.ByLoft and Curve.SweepAsSolid errors and fails

i tryed different ways to sweep along a curve. The curve is inside a linked dwg in Revit.
I recreated the curve with points and NurbsCurve.ByControlPoints.
That seems to minimize a lot of errors afterwards.


  • sometimes errors, depends one number of profils (example 1)
  • sometimes not in the same place as dwg curve ( Example 2 -1)
  • needs a lot of time to calculate


Its not easy to look at the geometry in Revit, because of the length.
But a good way to check the results is to look at the volume of the solids.
So…no error occurs, but some volumes are null or nearly 0. So the geomtry is realy flat…this means the profiles are not correct sweeped along the curve.

I would like to use a 1cm radius, but if i choose a smaller radius, other errors occur…

I work in RVT 2020.2 and use Dynamo 2.3
Packages i used:

example files:
test.dwg (162.7 KB)
test_dwg_to_sweep.dyn (151.3 KB)

Any ideas how to sweep save along curves?

Hi @Fiesta

Maybe this helps