Graphical Numerical Control (GNC) is a technology that uses graphical interfaces and digital instructions to control machine tools. It allows operators to program tools by inputting instructions that specify tool paths and machining parameters on a computer screen. Some key advantages of GNC include increased efficiency, improved accuracy from precise tool paths, and flexibility to easily reprogram machines. GNC sees applications in CNC machining, robotics, additive manufacturing, and more. While powerful, GNC systems also have drawbacks like high costs, specialized skill requirements, and complexity.

1. Graphical Numerical
Control(GNC)
Presented By:
Ashish Kumar Chaurasiya
214122007
CNC Technology (PR605)
M. Tech, 2nd Semester
Manufacturing Technology
Department of Production Engineering
National Institute of Technology Tiruchirappalli,
Tamil Nadu - 620015

2. CONTENTS
historical overview
Introduction
Difference between NC and GNC
Steps in programming
Example of Graphical Numerical Control (GNC)
Advantage and Disadvantage
Applications of GNC technology
Conclusion

3. Historical overview
1949: The first numerical control (NC) machine is developed by John T. Parsons, which
used punched cards to control the movement of a cutting tool.
1952: MIT professor Patrick H. Whitney develops a prototype of a computer-controlled
milling machine, which used digital instructions to control its movement.
1960s: The introduction of minicomputers and the development of computer-aided design
(CAD) and computer-aided manufacturing (CAM) systems allowed for more sophisticated
GNC systems.
1970s: The first GNC systems using cathode ray tube (CRT) displays were introduced,
allowing for real-time monitoring of the machine's performance.
1980s: The introduction of personal computers and graphical user interfaces (GUIs) led to
the development of GNC systems with more user-friendly interfaces.
2000s: The development of 3D printing and additive manufacturing technologies further
expanded the capabilities of GNC systems, allowing for the creation of complex 3D
structures.

4. Continued

5. Introduction
 Graphical Numerical Control (GNC) is a technology used in manufacturing that
enables machines to be controlled using graphical interfaces and digital
instructions.
 GNC systems typically include a computer, a user interface, and a machine
tool or robotic system that is controlled by the computer.
 The user interface allows the operator to program the machine tool or robot by
inputting digital instructions that specify the desired tool paths, cutting speeds,
and other machining parameters.
 GNC systems can use a variety of programming languages to specify the tool
path and other machining parameters, including G-code.
 GNC technology is widely used in CNC machining applications to control the
movements of machine tools such as lathes, mills, and routers.

6. Difference between NC and GNC
 NC technology uses a set of digital instructions, known as G-code, which
specifies the movements of the machine tool or robot. These instructions are
typically entered manually into the NC system, either through a computer or a
programmable logic controller (PLC).
 GNC technology, on the other hand, uses a graphical interface to program the
machine tool or robot. The operator can input digital instructions by selecting
and dragging objects on a computer screen, rather than typing in lines of G-
code.
 GNC technology is often used in applications that require more complex
movements, such as 3D milling, where the operator can visualize the part being
machined in real-time.
 Another key difference between NC and GNC is that GNC systems typically
have more user-friendly interfaces and are easier to learn and use.

7. Steps in programming
The steps in programming include:
 Study of production drawing and other documents prepared by planning
department.
 Determination of stock size.
 Study of machine tool specifications and features of control syst
 Deciding the setups and Tool selection
 Selection of technological parameters like speed, feed, etc.
 Tool path determination

8.  Program transfer to the Mchine.
 Tool path simulation/program simulation.
 Program testing—dry run, and debugging.
 Manufacture of components.
 Documentation for future reference.
 Preparation of working sketches and calculations, if needed.
 Program preparation (manually or by computer).

9. Example of Graphical Numerical Control (GNC)
 An example in action could be a 3D milling operation.
 In this scenario, an operator would use a GNC system to program a milling machine to
carve out a complex shape from a solid block of material, such as a part for an
aerospace or automotive application

10. Milling with drilling
 The operator would start by creating a 3D model of the component on the
computer screen, and then define the milling and drilling operations by selecting
and dragging objects on the screen.

11. Codes used in GNC technology
 GNC technology uses several types of codes to program machine tools or robots, including:
 G-code:G-code is typically used to specify toolpaths, cutting parameters, and other machining
operations.
 M-code:to control the non-cutting actions of a CNC machine, such as starting or stopping the
spindle, turning on or off coolant, or opening and closing machine doors.
 CAD/CAM:CAD and CAM software are used to create the 3D models of the parts to be
machined, and to generate the toolpaths and cutting parameters needed to program the GNC
system.
 PLC: Programmable Logic Controllers are used to control the operation of robots and other
types of automation equipment in GNC systems.

12. Standard G and M Codes:
 G-codes (preparatory functions), and M codes (miscellaneous functions).
 G-codes are sometimes called cycle codes because they refer to some action
occurring on the X, Y, and/or Z-axis of a machine tool.
 G-Codes (Preparatory Functions):
 Code Function
 G00 Rapid positioning
 G01 Linear interpolation
 G02 Circular interpolation clockwise (CW)
 G03 Circular interpolation counterclockwise (CCW)
 G20 Inch input (in.)
 G21 Metric input (mm)
 G24 Radius programming

13. Code Function
 M00 Program stop
 M02 End of program
 M03 Spindle start (forward CW)
 M04 Spindle start (reverse CCW)
 M05 Spindle stop
 M06 Tool change
 M08 Coolant on
 M09 Coolant off
 M10 Chuck - clamping

14. Advantage
 Increased efficiency: GNC technology allows for faster and more accurate
machining .
 Improved accuracy: The use of digital instructions and precise tool paths in
GNC technology ensures that machining operations are carried out with a high
degree of accuracy and consistency.
 Flexibility: GNC technology allows for the easy reprogramming of machine tools
and robots to adapt to changes in production requirements.
 Ease of use: The graphical user interfaces used in GNC technology are user-
friendly and intuitive.
 Safety: GNC technology can improve safety by allowing operators to control
machines from a safe distance.

15. Disadvantage
 High cost: GNC technology can be expensive to implement, requiring
significant investments in hardware, software, and training.
 Skill requirements: GNC technology requires operators with specialized skills
in programming, CAD/CAM, and machine operation, which can be difficult to
find and expensive to train.
 Maintenance: GNC systems require regular maintenance and updates to
ensure optimal performance, which can add to the cost and complexity of the
technology.
 Complexity: GNC technology can be complex, requiring a high degree of
technical knowledge and expertise to operate and maintain.
 Dependence on technology: GNC technology relies on computers, software,
and other digital systems, which can be vulnerable to cyber-attacks.

16. Applications of GNC technology
 CNC Machining: o control the movements of machine tools such as lathes, mills, and
routers.
 Robotics: GNC technology is used in robotic systems to control the movements of
robot arms, end-effectors, and other components.
 Additive Manufacturing: GNC technology is increasingly used in additive
manufacturing processes, such as 3D printing, to control the deposition of material.
 Inspection and Quality Control: GNC technology can be used in inspection and quality
control processes to ensure that manufactured parts meet the desired specifications
and tolerances.
 Assembly: GNC technology is also used in assembly processes to control the
movements of machines and robots.

17. Conclusion
 GNC is a computer-based control system that is widely used in manufacturing
industries to automate the operation of machine tools.
 It is a critical aspect of modern manufacturing and has become an essential tool
for producing high-quality parts in a wide range of industries, including
aerospace, automotive, and medical device manufacturing.

18. References
 [1] M. Kahrizi, machining Techniques for NC machine, InTech, 2012.
 [2] Hascalik, A., Çaydaş, U., Gürün, H., 2007, Effect of Speed on machine of Al Alloy.
Materials & Design, 28:1953–1957.
 [3] Wang, J., 2009, A New Model for Predicting the Depth of Cut in NC Contouring of
Alumina . Journal of Materials Processing Technology, 209:2314–2320.
 [4] Folkes, J., 2009, MIlling—An Innovative Tool for Manufacturing. Journal of
Materials Processing Technology, 209:6181–6189.
 [5] Kalpana, K., Mythreyi, O., Kanthababu, M., 2015, Review on Condition Monitoring
of Machining System. 2015 International Conference on Robotics Automation Control
and Embedded Systems (RACE), 1–7.
 [6] Aydin, G.,Karakurt, I., Aydiner, K., 2011, An Investigation on Surface Roughness of
Machined by GNC. Bulletin of Materials Science, 34:985– 992. [7] Azmir, M., Ahsan,
A., 2009, A Study of Machining Process on material. Journal of Materials Processing
Technology, 209:6168–6173.

19. Thank You