Using CAD for CNC Machining

This Part Drawing can be used to machine, in the way you want the operations to be performed.
Looking at the part to be made, will require 3 machine operations.
Spot and drill 5 holes
Circular pocket mill the large hole
Mill the outside profile



In this example I'm using the CMS IntelliCAD 6 SE program.

Point is the First CAD command and the First machining operation.
Clicking on the Circle places a dot in the center of each Circle. Points are used for Drilling and can be selected in the order of Drilling.
Starting with the Center, moving to the lower Left Circle, up to Top Left, over to the Top right and to the lower Right.


This is the way the DXF conversion program will see XY Points.
The Gcode would look like this.
N10 ( 1/4" Spot Drill )
N20 M6 T1
N30 M3 S8759
N40 M8
N50 G00 G43 H1 Z0.1000
N60 G81 X1.0000 Y1.0000 Z-0.125 R0.1000 F17.5
N70 X1.7501 Y0.2500
N80 X1.7500 Y1.7501
N90 X0.2499 Y1.7500
N100 X0.2500 Y0.2499
N110 G80



The Next Machining Operation is to Mill a Circular Pocket.













Using the Gcode from Pocketing program for the Center Circle.
Next Operation Cut the Outside Profile

















Using these CAD commands, Pedit, Explode and Offset for the Next operation.
First CAD command is Pedit, this converts Lines and Arcs to a Polyline.
The reason to use Polyline, is its easier to offset the part for the cutter used.
The Inner square is the part and Outer is the Tool path offset, by half the cutter diameter used.
The short line on the Tool path is the lead in/out for the cutter's start point.
Can be added to any point on the Polyline you want, by Exploding the drawing.
Then using Pedit to convert back to a Polyline for the finished profile.
The DXF file conversion program now knows where to start an end the cut.
Taking all the gcode files and using Windows Notepad program.
Doing a little Cut and Paste a complete Gcode program can be created.
Then run in Mach 3 Mill, to verify there are no mistakes.

Click on the Links
DXF conversion programs
CNC Projects
4th Axis Timing Pulley Maker