Chapter 1 - Introduction

System Characteristics

The Bridgeport Anilam Crusader II CNC Mill is the oldest working Computerized Numerical Control (CNC) mill in use by the ETSU Department of Technology. This CNC mill consists of a 3-axis closed-loop Anilam Crusader II CNC controller retrofitted to an existing Bridgeport Series I vertical spindle milling machine. The Bridgeport's saddle and table axis handles, dials, and acme lead screws were removed and replaced with ball screws and servo motors. The quill was fitted with a ball screw and servo motor to make the 3rd axis.

Introduced in 1979, the Crusader II controller is a EIA-274 / conversational programmable CNC controller for use on machine tools with up to 3 axes and uses an LED display. For more information, see the Anilam website at http://www.anilam.com.

Features

The Bridgeport/Anilam Crusader II CNC's many features include:

• It can operate in either the incremental positioning mode (G91) or absolute positioning mode (G-90)--and you can go back-and-forth between these modes. It defaults to absolute mode (G90).
  
  
• Will accept tool length offsets (TLOs) thru either numerical data or by digitizing.
  
  
• It can execute loops (DO) repeated up to 999 times.
  
  
• It can execute macros--or subroutines--(CALL) nested up to 32 levels deep.
  
  
• Subroutines can be rotated about the origin to any desired angle.
  
  
• It can cut angular paths (linear interpolation) in the X-Y, X-Z, Y-Z, and X-Y-Z planes.
  
  
• It can cut circular paths (circular interpolation) in the X-Y, X-Z and Y-Z planes and perform thread milling (helical interpolation).
  
  
• It can scale a part up or down--make it larger or smaller (G53).
  
  
• It can operate in either metric (G71) or inch (G70) units. It defaults to inch units.
  
  
• It has cutter compensation capability (G41-42) to permit the use of undersize or oversize cutters.
  
  
• It has canned X-Y axis cycles for hole milling (G76), circular pocket milling (G77), frame milling (G75), rectangular pocket milling (G78), and bolt circle drilling (G79).
  
  
• It has canned Z-axis cycles for drilling, spotfacing, peck drilling, chip-breaker drilling, and three boring cycles.
  
  
• The origin can be established anywhere desired and moved to another location whenever desired.
  
  
• Its range of axis motion is: X=24.0 Y=10.5 Z=4.0
  
  

Programming Formats

There are two ways to program the Anilam Crusader II:

1. By entering the data manually through the controller's console--referred to as Manual Data Input (MDI).
   
   
2. By entering the data via punched tape through a tape reader connected to the controller's RS-232-C serial port.
   
   

Data entered manually on the controller's console is formatted differently--in a "conversational" format referred to herein as the "Anilam Format." Data entered via a microcomputer or punched tape through the RS-232-C serial port uses the EIA RS-274-D format--with certain modifications.

The following pages list most of the factors that you must consider when writing a program for the Mill Crusader. It will show you step-by-step procedures for utilizing loops, macros, canned cycles, circular interpolation, and tool length offsets (TLOs). Instructions are also given for manual data input (MDI), tape input and output via the Program Saver magnetic tape recorder and the DSI paper tape punch/reader. Refer to the Crusader II Programming Manual for more detailed instructions, diagrams, and examples.

Last updated on Jan. 18, 2003 by Bill Hemphill