Chabot College
Fall 2010
Course Outline for Machine Tool Techology 71A
NUMERICAL CONTROL PROGRAMMING I
Catalog Description:
71A – Numerical Control Programming I
(May be repeated 3 times)
4 units
Introduction to programming and operating three-axis computer numerical controlled drilling and milling
machining centers. Instruction includes the XYZ Cartesian Coordinate system, manual and automatic
machining center operation, absolute and incremental positioning, program coding and preparation,
fabrication of basic three-axis drill and mill parts, and laboratory “first article” inspection reports. Strongly
recommended: Industrial Technology 74. 2 hours lecture, 6 hours laboratory.
[Typical contact hours: lecture 35, laboratory 105]
Prerequisite Skills:
None
Expected Outcome for Students:
Upon completion of the course, the student should be able to:
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set tool length offsets;
set fixture offsets;
create CNC mill part programs;
edit CNC mill part programs on machine controllers;
write point-to-point drilling and tapping programs;
write simple contouring programs;
test run and fabricate simple CNC mill parts;
calculate feeds, speeds, and dwell times;
calculate cutter locations with a hand calculator;
calculate polar coordinate positions;
use subprograms for looping and repetitive operations;
solve simple trigonometry problems;
use the control math functions to calculate cutter locations;
transfer edited programs from the machine’s control to computer;
use a computer to write and transfer part programs across a network;
inspect fabricated parts on a coordinate measuring machine;
write a “first article” inspection report for each assigned project.
Course Content (Lecture):
1. Introduction to Numerical Control
a. Cartesian coordinates
b. Tool and fixture offsets
2. Program format
3. Preparatory and miscellaneous codes
4. Canned cycles
a. Feed plane and initial plane
b. Feed, speed, and dwell calculation
c. Drill and spot drill depth calculation
d. Calculator functions
5. Introduction to the Coordinate Measuring machine
a. First article inspection
b. Lab inspection reports
Chabot College
Course Outline for Machine Tool Technology 71A – Page 2
Fall 2010
6. Calculating bolt circles
a. Rigid tapping
b. Calculator functions 2
7. Incremental and Absolute programming
a. Polar coordinates
b. Coordinate shift
8. Introduction to Conversational Programming
a. ProtoTrak vertical mill tool length offsets
b. Conversational programming
9. Sub Programs
a. Looping
b. Position preset function (G92)
10. Introduction to contouring
a. Cutter diameter compensation
b. Climb and conventional milling
11. Special machining center functions
a. Mirror imaging
b. Rotations
c. Pythagorean Theorem
12. Cutter location calculation
13. Special milling cycles
14. Fixed subroutines
15. Parametric programming
16. CNC software applications
17. Machining center simulator functions and operation
18. Automatic tool setters
a. Touch probes
b. Laser tool set stations
Course Content (Laboratory):
1. Techniques:
a. Set tool length offsets
b. Set fixture offsets
c. Edge finding routines
d. Indicating part features to use in fixture offsets
e. Create part programs from engineering drawings
f. Proof programs on machine tool simulators
g. Test run programs
h. Fabricate programmed parts
i. Calculate spot drill depth adjustments
j. Edit part programs in the CNC mill controller
k. Inspect parts with a coordinate measuring machine
l. Inspect parts with manual inspection tools
2. Safety:
a. Safe operation of the CNC machining centers
b. Safe program proofing procedure
Chabot College
Course Outline for Machine Tool Technology 71A – Page 3
Fall 2010
Methods of Presentation:
1. Lecture, informal with student questions encouraged
2. PowerPoint presentations, videos, instructor created movies, and overhead transparencies
3. Demonstrations
Assignments and Methods of Evaluating Student Progress:
1. Typical Assignments
a. Homework: 1-3 worksheets each week on the material covered in the text and in lecture.
1) Examples: Sketch the outer contour project, draw in the tool tangency locations, and
calculate their Cartesian coordinate positions.
2) Write a program using G98 / G99 to jump over clamps on the frame project.
b. Laboratory assignment: Write a program to spot drill and drill the ten 5/16 diameter holes
shown in the frame drill engineering drawing. Load the program into the CNC machining
center and test run each tool path operation checking for accuracy and proper tool path.
Spot drill only the first hole and measure the spot diameter. Calculate the spot drill depth
adjustment and edit the adjusted value into the part program. Run the program from the
beginning to fabricate the part. Inspect the part on the coordinate measuring machine and
create a “first article” inspection report. Did the part pass inspection? If not, why?
2. Methods of Evaluating Student Progress
a. Homework
b. Quizzes
c. Written laboratory inspection report on each part project
d. Fabricated parts checked to be accurate size and shape
e. Midterm examinations
f. Final examination
Textbook(s) (Typical):
Haas VF2 Mill Programming Manual
This is the programming manual for specific equipment in Chabot's Machine Tool Technology lab.
It is the standard for all operations and programming functions for our equipment.
Special Student Materials:
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Machine shop approved safety goggles
Sharp EL-531W scientific calculator
Plastic circle template, 6” rule, protractor, compass, three inch 30-60° and 45° triangle
USB drive – 1gb minimum
Headphones – 1/8” stereo jack
Combination or keyed padlock
Revised: 9/29/09;
Ashley Long/Mike Absher