Learning CNC with CNC Machining Center or Turning Center

Almost all CNC using companies have at least one turning center or machining center. If you are not versed fully with its usage, it’s likely that you’re not taking full advantage of what these sophisticated machines can do. These two courses teach CNC machining center and turning center usage from the ground up using the proven key concepts approach.

The CNC principles are best introduced and learned during discussions of manual programming (also called G code programming). Concepts like program zero assignment, compensation, motion types, and special features are easy to master at G code level. Yet many CNC people that use CAM (computer aided manufacturing) systems avoid G code level programming like the plague. Or worse, they have never been exposed to it. All CNC people should have a good working knowledge of G code - especially if program changes must be made during a program’s verification regardless of how you develop programs. It produces is like using a calculator without understanding basic arithmetic using a CAM system without understanding the G code level programs! It is the chance to get up to speed!

While the key concepts can be applied to any CNC turning center or machining center, all specific examples are given in the format for the Fanuc control, the industry standard for CNC. Fanuc is so popular that many control manufacturers claim to be Fanuc-compatible including Haas, Yasnac, Mitsubishi, and Hitachi.

»»  CNC PROGRAMMING...“Learning CNC with CNC Machining Center or Turning Center”

The History of CNC Development

The History of CNC Development

The CNC is call for computer numerical control and it is refer to a computer “controller” which specifically drives a machine tool and reads G-code instructions, typically a powered mechanical device used to fabricate components by the selective removal of material. CNC does numerically directed a cutting tool interpolation in the work envelope of a machine. The CNC operating parameters can be altered via software load program.

CNC was preceded by Numerically Controlled (NC) machines, which were hard wired and their operating parameters could not be changed. NC was developed in the late 1940s and early 1950s by John T. Parsons collaboration with the MIT Servomechanisms Laboratory. The first CNC systems used hardware of NC style, and the computer was used for the tool compensation calculations and sometimes for editing.

Punched tape was continued to be used as a medium for transferring G-codes into the controller for many decades after 1950, until it was eventually superseded by floppy disks, RS232 cables, and now is commonly tied directly into plant networks. The G-codes files to be interpreted by the controller are usually saved under the .NC extension. Most shops have their own saving format that matches their requirements of ISO certification.

The CNC machines introduction radically changed the manufacturing industry. Curves are as easy to cut as straight lines, complex 3-D structures are relatively easy to produce, and the number of machining steps that required human action has been reduced dramatically.

»»  CNC PROGRAMMING...“The History of CNC Development”

Why CNC (Computer Numerical Control)?

Why CNC (Computer Numerical Control)?

It has been a privilege to be part of the Precision Machining
Technology Competition for the past 9 years. I am proud to have
the opportunity of working with the fine young people from all parts
of the United States. They deserve the best that the educational
system and VICA can provide to prepare them for a future in this
rapidly changing technological world and make their contribution
to the country’s economy.
My enthusiasm for VICA and the young competitors is still very
strong, however there seems to be a serious lack of preparation
for students from metalworking/manufacturing related courses in
the basic knowledge of CNC. CNC, not a new technology having
been around since 1957, is one of the key factors in the manufacture
of most products in the world today. A knowledge of CNC, for
a technology student, should rank in importance along with the
ability of speaking proper English and reading technical prints
(blueprints).
As a former educator and now the Team Leader of the CNC VICA
competition, I feel so sorry for contestants in the Milling and
Turning who sit in front of a computer and do not know how to load
a program or the basics of CNC programming. These students are
naturally frustrated that an educational system has shortchanged
them by not realizing that metalworking technology has changed
dramatically over the past 40 years. That some schools prepare
students for the National VICA Precision Machining Competition
with 50-year-old technical knowledge is something very difficult to
understand.
The International (World) competition eliminated conventional
machine tools from the precision machining competition in 1996,
and it now consists of 100% CNC competition. To send our national
winner to the world competition without a good background
in CNC programming and machining would be a reflection on, and
a disgrace to the US educational system.
The educational community and National VICA must work
together to correct this lack of CNC knowledge and training.

The VICA CNC Programming Guide covers the basic CNC principles
and gives detailed explanation of each step in the programming
and turning a part. The time and money spent to prepare and
distribute this Guide will be wasted unless the metalworking/
manufacturing teacher is committed to introducing CNC as part of
the curriculum.

The following suggestions can be used to introduce CNC theory
and technology to metalworking/manufacturing courses:
1. Teach the basics of CNC using the VICA CNC Programming
Guide that should be supplemented by a textbook, visuals, videotapes,
etc. - COST approximately $200.00.
2. Use the VICA CNC Programming Guide and textbook along
with CAD/CAM software that allows a student to simulate the
machining of a programmed part on the computer screen. - COST
approximately $600.00.
3. Use the VICA CNC Programming Guide, textbook, CAD/CAM
software, plus a CNC Bench-Top teaching size machine. This is
by far the best method since students can actually produce a real
part that they can hold and take home to show their parents. -
COST approximately $6,000.00

For more information from a leader in CNC educational
courseware, software, and Bench-Top Teaching machines contact:

Denford Inc.
1-800-886-9750
www.denford.com
E-mail: sales@denford.com

The old argument that there are still many shops using old
technology is a fallacy used consciously or unconsciously by those
resisting changes. Over 90% of the machine tools manufactured
in the world have some form of CNC control, therefore conventional
(manual) machines should be used to provide only the basic
knowledge of machines and machining processes.

We must all do our part; State Directors, District Directors, School
Administrators, and Classroom Teachers to correct a problem long
overdue in technical education.

Steve Krar
CNC Team Leader
Precision Machining Technology

»»  CNC PROGRAMMING...“Why CNC (Computer Numerical Control)?”

Cnc Program Machining the square groove

Machining the square groove

N30 X.375

• Y-.375 : tool rapids to position A.

N35 G01 Z-.125 F10

• G01 linear interpolation.
• Z-.125 tool feeds 
• .125 below the work surface.
• F10 feed rate set at 10 in./min.

N40 X1.625 Y-.375

• X1.625 top groove cut to the right hand end.
• Y-.375 measurement did not change because it was set in block N30.

N45 Y-1.625

• Y-1.625 right hand side of the groove cut.

N50 X.375

• X.375 bottom groove cut to the left side.

N55 Y-.375

• Y-.375 left-hand side of groove cut; this completes the groove.

N60 G00 Z.100

• G00 rapid traverse mode.
• Z.100 tool rapids to
• .100 above work surface. 

It's easy not to make a cnc program, the most important key is we know the basic origin for a programming

»»  CNC PROGRAMMING...“Cnc Program Machining the square groove”

Basic Computer Numerical Control Programming

1. Identify the names and functions of some common parts of a computer.
2. Identify and use correctly vocabulary related to CNC machining.
3. Define CAD and CAM.
4. Fill out a chart with information that a supervisor gives to a new employee.
5. Analyze information from a line graph.
6. Identify the main idea and supporting details by outlining and mapping a reading.
7. Label the parts of a CNC machining center.Graphing  functions and  axis(  XYZ)
8. Locate and plot  points in a two-axis Cartesian  coordinate system 
9. Absolute position
10. Incremental position
11. Polar position
12. Explore and understand G and M codes

• Other addresses
• Machining function
• Program start definitions
• Straight line programming using manual cutter radius comp
• Basic M1 print (power point)
• Programs end definition
• Modals

»»  CNC PROGRAMMING...“Basic Computer Numerical Control Programming”