[Adamx]

Thanks heaps for your responses, I am learning inventor at the moment but use 3ds max for most 3d work as I know it very well. I am actually trying to engrave on stainless steel dog tags but the tags have a slight concaveness to them. I decided to do a manual "digitize" of the surface and got a pretty accurate 3d result in Max (I know it's not the right program for the job, but Im not up to producing 3d splines in Inventor yet..).

I then created the text to be engraved and projected it onto the surface to produce to 3d splines that I wanted to export to Sprutcam so I could use the 3d curve milling operation . I can import the model as an stl file which only has the 3d faces but no splines.

Just gary, I imported your Hex head into Sprutcam and the curves imported ok, they lie on a 2d plane.

I just tried exporting from max to an iges file and it looks like the curves have come in accurately. I am going to try and use the 3d Curve milling operation in Sprutcam to engrave. I'm pretty new to Sprutcam too so I'm not sure how it will all work.

Thanks again