The NX turning tool definition allows users to enter X Offset and Y Offset values on the Tracking tab:
These fields are used to apply an XOFF and/or YOFF value to the tool coordinates, which is needed in certain cases, such as when using preset tooling that is not gaged to the part. A default lathe post is set to use "Tool Tip" output, which means that the tracking point defined will be the coordinates of the tool in the posted code. This does not use any X or Y offset values entered on this dialog – these fields are simply ignored by the post.
In order to have the X and Y offsets applied to the coordinates in the post, you have to change the machine tool definition within the post. Launch Post Builder and open the lathe post. Go to the Machine Tool tab and change the Output Method option to "Turret Reference."
With this change in Output Method, the post becomes aware of the X and Y offset fields, and a set of coordinate manipulations is automatically added to the MOM_before_motion event. The post will now use a new set of internal calculations to adjust the coordinates and output the values based on the mom_ref_pos variable arrays. The NX Help describes these variables:
This change in post processor math is not readily apparent in post builder, but comparing the actual .tcl files for two lathe posts that are identical except for the change in Output Method will show the extra functions that have been added (the turret reference post is on the left below). Note that the turret reference post is swapping in the mom_ref_pos values for the normal mom_pos position values before every motion event, so the output words use those coordinates instead (with the X and Y offset values from the tool definition already applied). It's also doing much of the same for arc center points, from moves, and gohome moves to make sure that all the motion points are being output with the mom_ref_pos family of values:
This is all automatic. All the user needs to do is make the change in the machine tool definition and save the post. Post Builder handles the rest. This does mean that all the coordinates are adjusted before output, so it is highly recommended that the post goes through another prove out process to make sure that the new output is safe before using the code in production.