CNC PROGRAMMING

 "Swarfologist "

By Jim Cahill

This demonstration program is intended to be used by anyone who wishes to acquire some familiarity with CNC programming for recreational craft purposes. There is no need to possess a CNC machine or have any prior experience in using the technology. 

The demonstration version of Swarfologist will run on a PC.  Newer operating systems, may require "Compatability settings" to be used. Fast PCs will require slow feedrates to be entered to produce realistic behaviour. The demonstration version does not output commands, but is otherwise identical to a recent version of the operational software.   

CNC Demonstration Program

A brief introductory document is available in .pdf format.

Introductory Document

The operational version of Swarfologist has been used successfully for several years to control a Bridgeport Series 1 CNC milling machine fitted with a Textron Controller1. The software runs under Microsoft WINDOWS 982

The computer used was a 200Mz PC which performed perfectly satisfactorily for all my machining needs. Recently a 400 Mhz computer became available and the slower machine was replaced. Connection to the milling machine is via the LPT port. A purpose designed interface connects between the milling machine and the computer. The maximum feedrate which the computer can maintain in a linear move has been estimated to be about 3000 steps per second. This would correspond to 180 inches per minute on the Bridgeport, three times the original design speed. With the operating system configured appropriately, axis motion is completely smooth, even at high feedrates.   

Swarfologist was developed for personal use in a Home Workshop environment.  Swarfologist recognises a sufficient number of the "G" codes necessary to produce a finished component. Certain commands particularly applicable to production environments have not been implemented.

The following are sample part programs which can be edited in a text editor.

Part program  for cutting a set of 6 flats on a boss in a regular hexagonal configuration.   

Part program to drill a set of 6 holes in a regular hexagonal configuration using a pecking cycle.   

Part program written to increase the bore diameter of a boss using circular interpolation.   

Part program which uses circular interpolation to machine a flat surface.   

Part program to drill a set of 6 through holes.   

 

1. "Bridgeport" and "Textron" are proprietary  to Bridgeport Machines Ltd.

2. WINDOWS 98 is a registered trademark of Microsoft Corporation.