Pocketing - Plunge Location

In this Topic Show

Introduction

This topic explains how to define the plunge location for pocketing toolpaths. This information applies to both the Plunge Point for Mill 2 Axis Pocket operations, and the Drill Tip Positions for the Mill 3 Axis Advanced Rough operations.

 

Mill 2 Axis Feature

TreeMinusWEndLines.pngFeatureIconWhite.png Feature 2 Axis

      TreeLinesBranch.pngRedPlusIcon.pngGeometryIcon.png Geometry

      TreeLinesBranch.pngRedPlusIcon.pngStartPointIcon.png Default Chain Start Point

      TreeMinusThruLines.pngPocketOperationIcon.png Pocket

            TreeLinesElbowEnd.pngRedPlusIcon.pngStartPointIcon.png Plunge Point

 

Mill 3 Axis Feature

TreeMinusWEndLines.pngFeatureIconWhite.png Feature 3 Axis

      TreeLinesBranch.pngRedPlusIcon.png  3AxisGeoIcon.png   Geometry

      TreeLinesBranch.pngRedPlusIcon.png  GeometryIcon.png   Boundary

      TreeMinusThruLines.pngPocketOperationIcon.png Advanced Rough

            TreeLinesBranch.pngRedPlusIcon.png  GeometryIcon.png  Boundary

            TreeLinesBranch.pngRedPlusIcon.png  StopPointIcon.png  Drill Tip Positions

            TreeLinesBranch.pngRedPlusIcon.png  3AxisGeoIcon.png  Operation Stock

            TreeMinusWEndLines.png CAMDefaultsIcon.png Gouge Check Surfaces

            TreeLinesBranch.pngRedPlusIcon.png   3AxisGeoIcon.png  Gouge Check Surfaces 1

            TreeLinesElbowEnd.pngRedPlusIcon.png   3AxisGeoIcon.png  Gouge Check Surfaces 2

            TreeLinesBranch.pngRedPlusIcon.png   3AxisGeoIcon.png  Gouge Check Surfaces 3

            TreeLinesElbowEnd.pngRedPlusIcon.png   3AxisGeoIcon.png  Gouge Check Surfaces 4

 

   

Purpose

The purpose of setting a plunge location is to allow you to define where the tool plunges into a pocket, for example, after drilling a hole to create an entry point for the roughing tool that clears the material from the pocket.

IMPORTANT:     You can alter the plunging location for a pocket when the plunge move is inside the part. It is not used to change plunge locations that are outside of the part (it is not a start point control).

The Part

The Stock with Pre-drilled Holes
Pocket_Plunge_Point_15.png Pocket_Plunge_Point_16.png

 

Before Plunge Location

After Plunge Location
Pocket_Plunge_Point_17.png Pocket_Plunge_Point_18.png
Pocket_Plunge_Point_20.png Pocket_Plunge_Point_19.png

Using Plunge Points

After creating either a 2-axis Pocketing operation or the 3-axis Advanced Rough operation, you can use the Feature in the CAM Tree to assign a plunge point or drill tip positions to these operations, respectively.

 

Important Notes

Closed Pockets

With closed pockets you can assign the plunge point anywhere inside the pocket, with the exception that it must clear the perimeter (walls) by a distance that is greater than the tool radius, or the point is ignored in the toolpath calculation.

 

The next two images show pocketing toolpath without a plunge location assigned. The plunge location for these pockets can be modified as desired, because the plunge location is inside of the part.

 

Pocket_Plunge_Point_1.png Pocket_Plunge_Point_9.png

 

 

After assigning a plunge point at the same depth as the feature, the toolpath is calculated to update the plunge location.

 

Pocket_Plunge_Point_2.png Pocket_Plunge_Point_3.png

 

Pocket_Plunge_Point_10.png Pocket_Plunge_Point_11.png

 

 

The toolpath now uses the assigned plunge location.

Open Pockets

Plunge points can only be defined for open pockets when there is a plunge move that is inside the part. In other words, there must be more than one region or group to use a plunge point with an open pocket.

IMPORTANT:     When setting a plunge location for open pocketing, you can first compute the toolpath without assigning the plunge location. This way you can see if there is more than one region (plunge moves inside of the part). If more than one region exists, then you can modify the plunge location inside the part geometry.

 

The following images show open pockets that contain only one region. Assigning a plunge point for this scenario does not change the toolpath, because the plunge moves are outside of the part (there is only one region).

 

Pocket_Plunge_Point_5.png Pocket_Plunge_Point_4.png

 

 

The next images show open pockets that have plunge moves inside of the part (there is more than one region). For this scenario, we can change the plunge location that is inside the pocket.

 

Pocket_Plunge_Point_6.png Pocket_Plunge_Point_12.png

 

 

After assigning a plunge point at the same depth as the feature, the toolpath is calculated to update the plunge location inside the pocket.

 

Pocket_Plunge_Point_7.png Pocket_Plunge_Point_8.png

 

Pocket_Plunge_Point_13.png Pocket_Plunge_Point_14.png

Tip - Multiple Depths and Ramping Below the Plunge Depth

When using multiple depths and turning on one of the ramping options (ramp or spiral), you can assign a plunge location to the bottom of the pre-drilled hole, and the toolpath is created with a standard plunge move into the hole, but then uses the specified ramping move for all depths below the plunge location.

 

The following is an example toolpath with two depth steps and the spiral ramping option turned on with no plunge location assigned. Notice the spiral ramp move is applied to all depths from the top to the bottom of the feature.

 

Pocket_Plunge_Point_21.png Pocket_Plunge_Point_22.png

 

 

A plunge location is then assigned at the bottom of the first depth cut as shown next.

 

 Pocket_Plunge_Point_23.png Pocket_Plunge_Point_24.png

 

 

After computing the toolpath with the assigned plunge location, the spiral ramping move is only applied below the specified plunge location. The first plunge move is a direct plunge into the pre-drilled hole location.

 

Pocket_Plunge_Point_25.png Pocket_Plunge_Point_26.png

Final Note About Expected Result

Without Adaptive Roughing

When you are using any cut pattern other than adaptive, the toolpath remains the same as before the plunge location is assigned. In this case, the toolpath plunges using the new location, and then feeds directly to the start of the toolpath.

 

With Adaptive Roughing

When you are using the adaptive roughing option, assigning a plunge location may change the entire toolpath, using the new plunge location.

Related Topics

The 2 Axis Pocket Operation

The 3 Axis Advanced Rough Operation

Milling Features in the CAM Tree