Standard

 

MCA 215 – CNC Lathe Manual Programming

Course Description

Provides instruction for the safe operation and manual programming of computer numerical controlled (CNC) lathes. Topics include: machine safety, command codes, program loading, machine setup, process control, and practical application.

 

Competency Areas

Hours

 

Machine Safety

Class

6

Command Codes

D. Lab

0

Program Loading

P. Lab/O.B.I.

4

Machine Setup

Credit

7

Process Control

 

 

Machine Safety

 

 

Prerequisite:

MCA 211

Corequisite:

 

 

Course Guide

 

Competency

After completing this section, the student will:

Hours

Class

D.Lab

P.Lab/

O.B.I.

MACHINE SAFETY

5

0

5

 

Compile a list of general safety rules that apply to chip removal machines.

 

 

 

 

Explain the safety measures and problems which apply specifically to automated movements of cutting tools on a lathe.

 

 

 

 

Determine what work holding devices and support attachments would cause problems during automated operations.

 

 

 

COMMAND CODES

15

0

10

Theory

Describe the binary system and how it works in programmable controllers.

 

 

 

 

Name the computer languages and describe their general characteristics.

 

 

 

 

Define the various codes and functions used in CNC programming.

 

 

 

 

Discuss the related machine tool movements resulting from the codes entered into the controller.

 

 

 

 

Define and list the auxiliary function commands.

 

 

 

 

Explain the use of "G" and "M" words

 

 

 

 

Explain how the "Z" axis is determined and why there are but two axises in programming a lathe.

 

 

 

Program generation

Write a program using all the computer words needed to set machine feeds, speeds, and linear and circular interpolation.

 

 

 

 

Test the program and correct any errors.

 

 

 

PROGRAM LOADING

15

0

10

Theory

Describe the methods available to load programs into a controller.

 

 

 

 

Identify the major parts and functions of a programmable controller.

 

 

 

Loading

Manually load a program into the controller explaining each function and what the machine reaction should be.

 

 

 

 

Demonstrate the setting of the Zero and radius center points.

 

 

 

Computations

Compute the feeds and speeds to establish values for the "F" and "S" words.

 

 

 

MACHINE SETUP

10

0

10

Program selection and setup

Select a program and determine the tooling required, the work holding device, cutting tool/tools, and work supporting accessories required to complete the operation.

 

 

 

 

Determine the type of material and prepare it for mounting in the lathe.

 

 

 

 

Explain how the work will be set up in the lathe.

 

 

 

Single stepping

Explain how to run the program one line at a time to test the process for accuracy and safety.

 

 

 

PROCESS CONTROL

15

0

5

Theory

Define manual process control methods, random sampling, destructive and nondestructive testing, and explain how these are used in process control.

 

 

 

 

Explain the differences between attributes and variables.

 

 

 

Control charts

Prepare control charts to graph both variations in tested attributes and variables.

 

 

 

 

Explain how self monitoring and self correcting machines work.

 

 

 

 

Discuss how cutting tool changes or wear compensations can be determined from test graphs.

 

 

 

 

Suggested Resources

 

Books

 

ASM International. (1989). Machining metals handbook (Vol. 16). Materials Park, OH: Author.

Baril, R. (1987). Modern machining technology. Albany, NY: Delmar.

Luggen, W. W. (1986). Introduction to NC-CNC operation. Englewood Cliffs, NJ: Prentice Hall.

McGeough, J. A. (1988). Advanced methods of machining. New York: Chapman & Hall.

Rizzo, L. (1985). CNC lathe. Garden City, NJ: Bergwall.

Smith, G. T. (1989). Advanced machining. New York: Springer-Verlag.

Walker, J. R. (1989). Machining fundamentals. South Holland, IL: Goodheart-Willcox.