Dear all ! 

I've been trying to set the "Common line cutting" property in Camduct when writing the NC file for my nest as guided by Autodesk Camduct Help on this link: 

http://help.autodesk.com/view/FABRICATION/2016/ENU/?guid=GUID-2C2968CC-36EA-4A3B-A883-2E15AC00E101

I use the plasma cut with my post processor is this:

As I followed all the instruction from the link above I came to set my "margin" between parts (before nesting) and tick the option "Common line cutting" before writing the NC for the sheet as below: 

1. Check setting of Keft values 

2. Automatically nest the items 

3. Select machine and "common cut line" properties before writing NC file 

4. Write the NC and check the NC file

Well, I expected that my tool won't cut the line between 2 parts which have line in common but as I can see in the NC file, the tool still will cut twice between the common line as I can see the code and I can zoom out the common line. 

I wonder if there is anything that I didn't do properly or I totally misunderstood the use of "common line cutting". 

Please give me advise !! 

Cheer!