NX Milling an Undercut Region Using a Surface Contouring Operation

A Surface Contour operation is created to mill an undercut region on a part. The intended cut might look something like the picture below.

When the tool path is generated, though, the tool cuts on top of the part instead of staying in the slot as seen in the following picture. What settings could be made to keep the tool cutting in the slot instead of on top of the part?

Solution

Select the Projection Vector -> Vector -> Toward Drive option from the pull down. When this option is set notice that the Back Off Distance field is now available.


This Back Off Distance setting will determine how the Drive Points will be projected along the Projection Vector onto the Part Geometry. If the Back Off Distance is too large than the drive points will be projected on to the top of the part. Pressing the Display Projection Vectors button will display a vector showing how the points will be created. The image below shows what the vectors would look like if this value is too large.


When this value is changed to a smaller number than the displayed vector will now be shorter. The Drive Points, in this case, will be generated correctly and the tool path will now cut in the slot instead of on the top of the part.

Hardware/Software Configuration

Platform: all
OS: n/a
OS Version: n/a
Product: NX
Application: CAM
Version: V1888
Function: SURFACE_CONTOUR

Ref: 002-8016068