Hello,I use AutoCad 2007 for most of my mechanical design work and often times will use Rhino to render a "realistic" copy for our sales team or marketing group.  Some years ago there was a nice online free service that I could upload my Cad file (Cad exported as a .sat ACIS file) and they would convert it to a .stp format that would nicely import into Rhino.I found that this was a good way to get Cad models to Rhino without any goofy open surfaces or conversion problems.Well now that service is not available and I wondered if anyone can suggest any other good way to accomplish this task.I realize that Rhino will insert or open .dwg files from Cad but again there are many times where surfaces are open or distorted and have to be rebuilt in Rhino.Thank you in advance for any help.

Hi,
 
try to export the Acad drawing file like an ACIS file (file/export....), then import this file in Rhino. It works in my case.
I hope it'll work and in your case.