best method for creating a 2D p/line for NC routing from 3D solid?

[ZedEverett]

Well this is driving me bonkers.. yes ,i have discovered a 3D polyline cant be joined to a 2D polyline and when i exploded 3Dpline then flattened it ,as recommended elsewhere on this forum,it seems its shrunk in length.The NC router I have access to has to use 2D polyline for the path of the cutter.I soooo wish i could simply fed the 3D object into the NC router software and that was all i had to do .Suggestions ,folks ?

[ZedEverett]

oops...forget to mention I am running 2011 AutoCad.I have tried exploding solid/pedit to convert spline to 3D polyline/flatten it,but this is no good it seems.

[ReMark]

Can you post a copy of the drawing wherein you have a 3Dpolyline and a 2Dpolyline that cannot be joined?

[Dadgad]

Well this is driving me bonkers.. yes ,i have discovered a 3D polyline cant be joined to a 2D polyline and when i exploded 3Dpline then flattened it ,as recommended elsewhere on this forum,it seems its shrunk in length.The NC router I have access to has to use 2D polyline for the path of the cutter.I soooo wish i could simply fed the 3D object into the NC router software and that was all i had to do .Suggestions ,folks ?

When you say that it shrunk in length? Wouldn't that be a logical consequence of removing travel along the Z axis?
When measured from WORLD UCS it would appear to be the same length, although in actuality it would have been shortened, when measured in 3D.
I'm with ReMark, skeptical about your claim that it cannot be joined to the 2D polyline. Happy to try if you post it, or maybe just those 2 particular lines from your drawing.

[ReMark]

I'm not skeptical. I have 2013 installed. The Join command will connect a 3Dpolyline to a 2Dpolyline.

[Dadgad]

I'm not skeptical. I have 2013 installed. The Join command will connect a 3Dpolyline to a 2Dpolyline.

That was my position too, I find it hard to believe that it can't be done (skeptical, if you will of the OPs conclusion). Remembering that he is on 2011 I still feel that there must be a way, without availing ourselves of that new functionality in 2013.

[ReMark]

I think it best the OP try JDM's suggestion despite the fun we have had at his expense.

[Dadgad]

I think it best the OP try JDM's suggestion despite the fun we have had at his expense.

FIRE IN THE HOLE!

Hell, I still want a shot at joining them, but we haven't been able to coax or cajole a sample yet!
And yeah explode would probably be my first step right out of the gate.

[ReMark]

Since I was curious about this I conducted a simple test.

I drew a 2Dpolyline and a 3Dpolyline (separate layers/colors) then used the JOIN command on them. I checked the Properties of the combined line AFTER joining them. AutoCAD said I now had a polyline. It made no difference which one I picked first when I executed the JOIN command.

[Dadgad]

That would be using 2013 I imagine? On differing planes?