A REPORT ON
CNC Technology and 21st Century
Submitted By -
NAME: - Suman Saha
DEPARTMENT: - ME
ROLL NO.: - 35000720055
SUBJECT: MANUFACTURING TECHNOLOGY
CODE: - PC-ME 601
SEM: - SIX
YEAR: - THIRD
Ramkrishna Mahato Government Engineering
College
ACKNOWLEDGEMENT
I the undersigned declare the report writing "
Manufacturing Technology" is based on my learning,
knowledge and own thinking, carried out from our syllabus
from. Manufacturing Technology (PC-ME601) under the
supervision of Our faculty Mr. MD Sahariat Hossain.I assert
the statements made and conclusions drawn are an outcome
of my project work. I further certify that.
I. That work contained in the project report is original
and has been done by me under the general
supervision of my supervisor.
II. I have followed the guidelines provided by the CBSE in
writing the project report.
III. Whenever I have used materials (data, theoretical
analysis, and text) from other sources, I have given
due credit to them in the text of the project report
and giving their details in the references.
Purulia Suman Saha
01/03/2023 35000720055
ABSTRACT
Machining is an important manufacturing process that is used in a
wide range of applications. From aerospace applications to the
manufacturing of energy systems and medical robots, we see a major
reliance on machining. In this project we focus on gaining an
improved understanding of the mechanics of machining and the
different factors that contribute to part quality. We acquired primary
machine shop skills that provided us an opportunity to mill and drill a
class of components to specified dimensions and tolerances. For
each component, we created a detailed engineering working drawing
that helped to shape and construct all the operations and procedures
that must be undertaken and controlled to attain component
machining without any breakdown or failure. Through hands-on
machining, we discovered many different factors involved in milling,
drilling, and the effects they exhibited on the tolerance and surface
finish of a part. The main relevant factors that we examined were
tool selection, speeds, feeds, and material selection. The extent to
which these factors can influence machining is presented. The
project establishes new ways to systematically perform machining in
a safe and stable manner without impacting the quality of
the surface finish.
CONTENT
I. Introduction
II. Origin And Evolution Of CNC
III. Components Of CNC
IV. Features And Operation In Different
Fields
V. Part Programming
VI. Advantages And Limitations
VII. Ongoing Research And Future
VIII. Conclusion
IX. References
INTRODUCTION
In computer numerical control (CNC), the control hardware
(mounted on the NC machine) follows directions received from local
computer software. There are two types of computerized systems:
direct numerical control and computer numerical control.
In direct numerical control (DNC), several machines are directly
controlled, step by step, by a central computer. In this system, the
operator has access to the central computer, and the status of all
machines in a manufacturing facility can be monitored and assessed
from the central computer. However, DNC has a significant
disadvantage: If, for some reason, the computer shuts down, all the
machines become inoperative. Distributed numerical control
involves the use of a central computer serving as the control system
over a number of individual CNC machines with dedicated
microcomputers. This system provides large memory and
computational capabilities and offers flexibility while overcoming the
disadvantage of direct numerical control.
Computer numerical control is a system in which a control
microcomputer (onboard computer) is an integral part of a machine
or piece of equipment. The part program may be prepared at a
remote site by the programmer, and it may incorporate information
obtained from drafting software packages and from machining
simulations (in order to ensure that the part program is bug free).
The machine operator can easily and manually program the onboard
computer, can modify the programs directly, prepare programs for
different parts, and store the programs. CNC systems are widely used
today because of the availability of small computers with large
memory, microprocessors, and program-editing capabilities, as well
as the increased flexibility, accuracy, and versatility of such
computers.
ORIGIN AND EVOLUTION OF CNC
When you look at the history of CNC machines, you will know that CNC
machining did not start as many people think it did. Presently, wherever
we say or see CNC machining, we expect a computerized process.
However, CNC machining, to be precise, was just recently
computerized.
This section will introduce you to CNC machining history, the first CNC
machine, and its evolution over time.
The first CNC machine was credited to James Parsons in 1949.
Parsons was a computer pioneer who worked on an Air Force Research
Project. The research was on how to produce helicopter blades and
better aircraft skin. Parsons was able to calculate helicopter airfoil
coordinates with an IBM 602A multiplier. He then fed the data into a
punched card, which he used on a swiss jig borer. This information led to
the manufacture of many helicopter blades and aircraft skins. According
to the accepted CNC history, this was considered the first CNC machine.
Parson would later receive the Joseph Maria Jacquard Memorial Awards
for his work.
Development of CNC Technology
1952-1958
As the Cold War became intense, there was a need to improve efficiency
and productivity in making many machines and weapons. Therefore, in
1952, Richard Kegg, together with MIT, made the first CNC milling
machine known as Cincinnati Milacron Hydrotel. Richard Kegg would
later file for a patent for the Motor Controlled Apparatus for Positioning
Machine tool in 1958.
1967-1972
CNC machining was becoming more recognized across the world. This
was due to the Computer-Aided Design (CAD) and Computer-Aided
Machining (CAM) development in 1972. CAD and CAM inclusion in CNC
machining led to massive developments in CNC machining. However,
the two were not regarded as a standard part of the manufacturing
process.
1976-1989
In 1976, 3D Computer-Aided Design and Computer-Aided Machining
were included into CNC machining. In 1989, CAD and CAM software-
controlled machines became the industrial standard for CNC machines.
Components Of CNC
1. SPINDLE
2. SADDLE
3. BASE
4. LINEAR MOTION GUID WAYS
5. PALLETE
6. AUTOMATIC TOOL CHANGER
7. HEAD STOCK
8. TAILSTOCK
9. TURRET ASSEMBLY
10. CONTROLLER
11. PUMPS
12. MOTORS
13. OUTER SHEET METAL BODY
Features And Operation In Different
Fields
1. The tool or material moves.
2. Tools can operate in 1-5 axes.
3. Larger machines have a machine control unit (MCU) which manages
operations.
4. Movement is controlled by a motor (actuators).
5. Feedback is provided by sensors (transducers)
6. Tool magazines are used to change tools automatically.
PART PROGRAMMING
PROGRAMING KEY LETTERS
O-Program number (Used for program identification)
N - Sequence number (Used for line identification)
G - Preparatory function.
x - X axis designation.
Y-Y axis designation Z-Z axis designation.
R - Radius designation.
F - Feed rate designation.
s - Spindle speed designation.
H - Tool length offset designation.
D-Tool radius offset designation.
T - Tool Designation.
M - Miscellaneous function.
EXAMPLE
Advantages And Limitations
1. High Repeatability and Precision e.g. Aircraft parts
2. Volume of production is very high
3. Complex contours/surfaces need to be machined. E.g. Turbines
4. Flexibility in job change, automatic tool settings, less scrap
5. More safe, higher productivity, better quality
6. Less paperwork, faster prototype production, reduction in lead times
Ongoing Research And Future
Advanced CNC technology can help a company to stay competitive
and acquire new products. In addition, advanced CNC machines
reduce costs and operate with an ever-growing arsenal of materials.
But the progress will not stop there. Machine builders continually
challenge the performance status quo. The industry 4.0 movement
helps to overcome these limits.
Industry 4.0 basically refers to a more complex manufacturing setup
that includes IIoT (Industrial Internet of Things) that monitors and
measures manufacturing processes and reacts autonomously when
something goes wrong. This ability helps CNC machines self-
diagnose problems and correct errors in the manufacturing process
faster than employees can detect and respond to errors or diagnose
the reason for machine malfunction.
For the industry specific example, the medical products industry
demands perfection in manufacturing processes because life
depends on fail-safe components. CNC machines and Industry 4.0
technology together ensure the production of high-quality
components for medical devices. CNC and CAM (Computer Aided
Manufacturing) machines are a combination that produces top
quality, flawless products at a significant profit, regardless of the
industry a manufacturer serves.
Advances in CNC machining continues to make the seemingly
impossible possible. Precision CNC machining is one of the fastest
evolving industries worldwide. So, just where is the industry going?
To conclude for now, the future of CNC machining is looking
toward synchronization of several machines which vastly increases
the efficiency and capability of prototypes to production
manufacturing facilities.
Conclusion
The history of CNC machining is unique. It has developed more from
the first CNC machine that required punch card to a software-based
machine that requires little guidance. CNC machining is the top
manufacturing process incorporated into many industries.
The importance of lathes and milling machines even if they are
conventional cannot be undermined. These machines have played a
real important role in bringing about industrial revolution and have
laid the foundations. But the bringing about of the new technology in
the present era is very important. The conventional machines are
required in small quantities whereas the CNC machines must be
increased to improve the quantity and quality of production.
References
S. Kalpakjian and S.R. Schmid, Manufacturing Processes
for Engineering.
M.P. Grover, Fundamentals of Modern Manufacturing
Ghosh & A.K. Mullick, Manufacturing Science
https://www.uti.edu/blog/cnc/6-cnc-machines
https://www.wikipedia.org/
https://www.linkedin.com/ f
https://www.slideserve.com/saul/cnc-machines
