CNC Part Programming

CNC Part Programming

CNC Part Programming

Introduction

Whether the machinist is drilling a hole on a CNC milling machine or machining a complex part on a machining center, setting up the machine to run a CAM program is essentially the same. First, the coordinate systems of the CAM system must be accurately matched to the machine tool. This is a one time process and most machine tools offer special verification tools to assist with this step. Then, the operator clamps the material or stock onto the machine tool and aligns it with the machine tool axis. If the stock is accurately represented as a solid in the CAM system, the machining process can begin. If not, the operator can place a special probe in the machine tool and bring the probe in contact with the stock to establish the stock dimensions (Holland, 2009, 85).

In the language of NC code, machining a straight line is a single command, but machining a circle requires multiple commands to tell the machine to move a small distance in X and Y, based on the accuracy required, until the circle is complete. The CAM system automates the creation of the NC code by using the geometry of the CAD model. To machine a circle, the CAM programmer simply selects the proper tool and the desired depth and indicates the circle in the CAD model he or she wants machined. The CAM system creates the complete NC tool path, from tool selection to the thousands of small incremental steps required to machine the circle. Taking this down to the level of the machine, many modern machine tools include circular interpolation as a standard feature of the machine controller.

Optimum Batch Size

3D and 2D images may be used to help you visualize your own designs for sheet metal manufacturing suitability or to relay your design ideas to your customers. Where you only have a sheet metal sample we can produce fully dimensioned 2D drawings to work to in our manufacturing plant, inspection and for your future design reference. These detailed dimensioned drawings can be output in AutoCAD® compatible file formats such as DWG and DXF. We can also import your 3D data from AutoDesk® Inventor and Solidworks® software (STEP and SAT formats) to speed up CNC punching program generation and reduce the chances of translation errors.

Exact 2 dimensional sheet metal flat pattern developments can be automatically and accurately produced by unfolding the 3 dimensional sheet metal model ready for the selection of the best CNC punch press tooling and the most efficient program nesting for a given sheet size. The sheets used are normally 2000mm x 1000mm or 2500mm x 1250mm in size. Other special sheet sizes can be sourced to reduce material wastage and of course smaller parts of sheets are used for smaller batch sizes or physically smaller parts making the process of CNC programming very flexible for batch manufacturing.

CNC Stages

The design is loaded into the computer which is attached to the CNC ...