Table of Contents 1.0
TITLE .................................................................................................................................. 3
2.0
OBJECTIVES ................................................. ..................................................... ..................................................................... ................ 3
3.0
INTRODUCTION ............................................................................................................... 4
3.1 4.0 4.1
Theory ................................................ ...................................................... .............................................................................. ........................ 4 APPARATUS ...................................................................................................................... 5 Industrial Apparatus ....................................................... ......................................................................................................... .................................................. 8
5.0
EXPERIMENTAL PROCEDURE ..................................................... ...................................................................................... ................................. 9
6.0
RESULT & DATA ANALYSIS ....................................................................................... 11
6.1
G Codes .............................................. ...................................................... ............................................................................ ...................... 12
6.2
Area Measurement of Final Product ............................................... ............................... 14
6.3
Sample of Calculation ................................................... ................................................. 15
7.0
DISCUSSION ................................................. ..................................................... ................................................................... .............. 16
8.0
CONCLUSION ............................................... ..................................................... ................................................................... .............. 17
9.0
RECOMMENDATION ..................................................... ..................................................................................................... ................................................ 18
10.0
REFERENCES .................................................................................................................. 19
11.0
APPENDICES ................................................................................................................... 20
Table of Figures Figure 1: Plasma cutting works....................................................................................................... 4 Figure 2: Computer Display............................................................................................................ 5 Figure 3: Dassault System Catia Software...................................................................................... 5 Figure 4: FastCam Software ........................................................................................................... 5 Figure 5: Huawei CNC Plasma Machine .............................................. .......................................... 5 Figure 6: Plasma Cutter .................................................................................................................. 6 Figure 7: Inverter Air Plasma Machine .......................................................................................... 6 Figure 8: Gas Tank.......................................................................................................................... 6 Figure 9: PLACOM Digital Planimeter ................................................ .......................................... 7 Figure 10: Grinding Machine.......................................................................................................... 7 Figure 11: Alpha 1530E CNC plasma cutter ................................................. ................................. 8 Figure 12: Baileigh PT-44VH P T-44VH CNC Plasma Cutting Table ....................................................... ............................................................ ..... 8 Figure 13: Hornet LT CNC Plasma Cutter ............................................................. ........................ 8 Figure 14: Final Product ............................................................................................................... 11 Figure 15: Area of the surface b y using Measure Inertia in Catia ................................................ 14
1.0 TITLE
ADVANCE MANUFACTURING (CNC Plasma)
2.0 OBJECTIVES
1. To identify and understand the main operation of a CNC machine. 2. To study how to use the machine to produce the product through the CNC process. 3. To identify the types and causes defects in plasma cutting. 4. To be able to use the computer programming to set up the product and subsequently generate through CNC machine.
3.0 INTRODUCTION
The numerical control (NC) is defined as programmable automation that the process is controlled by the commands programmed for the operation of the machines. In CNC systems, the design is highly automated for the mechanical part and its production program. CNC machining is a process used in industries that use computers to control the production of machine tools. The dimensions of the mechanical part are defined using the CAD software and then transferred to the production directives using CAM software (computer aided manufacturing).
3.1
Theory
The plasma cutting process is a process that cuts materials by creating an electrical overheating channel that produces hot plasma. The plasma is blown through a nozzle into the material at high speed When the electricity of the cutting torch moves mo ves along the plasma, it provides enough to melt the piece. At the same time, high-speed plasma and compressed gas blow hot molten metal, thus cutting the piece. Because plasma cutting produces a very hot cut cu t that is easy to cut, it is useful for cutting sheet metal with a curved or angled design.
Figure 1: Plasma cutting works The plasma cutter works by transmitting the electric arc through the gas that passes through the nozzle. Then the temperature of the gas increases to the plasma state. Since S ince the workpiece is a part of the circuit, the electrical conductivity of the p lasma causes the arc to transfer to the workpiece.
4.0 APPARATUS
APPARATUS
DESCRIPTION
Used to display the drawing of the product in 2D.
Figure 2: Computer Display
It is used as a medium to draw the shape of the product in 2D drawing.
Figure 3: Dassault System Catia Software
It changes the Catia drawing to the coding coordinate system so that the CNC machine can detect the shape of the product
Figure 4: FastCam Software
It is used to transfer data to the plasma cutter and control the movement of the cutter.
Figure 5: Huawei CNC Plasma Machine
APPARATUS
DESCRIPTION
It is used to cut the mild steel plate according to the desired shape.
Figure 6: Plasma Cutter
It is used to produce and supply plasma for the cutting process.
Figure 7: Inverter Air Plasma Machine
It is used to supply high pressure gas that combine with the plasma when cutting process is held.
Figure 8: Gas Tank
It is used to trace and measure the area of a 2D drawing.
It consists of a tracer that equipped with a magnifying glass which is needed to trace drawing manually.
Figure 9: PLACOM Digital Planimeter
It is used to grind the excessive metal as a finishing of the product.
Figure 10: Grinding Machine
4.1
Industrial Apparatus
APPARATUS
DESCRIPTION
widely used in cutting stainless steel, carbon steel and aluminum, one-off job or repetitive jobs.
The cutting speed is up to 6m/min.
Uses drive rack and pinion to move
Figure 11: Alpha 1530E CNC plasma cutter
the cutter
It includes a control podium and a hand-held unit that has X, Y, and Z jog controls.
The table has an industrial down shaft, water-based cooling and a ton of other
Figure 12: Baileigh PT-44VH CNC Plasma Cutting Table
Figure 13: Hornet LT CNC Plasma Cutter
features.
The cutting size area limit is 4ft x 4ft.
Advantages:
Durable Performance.
Powder coated metal surfaces.
High Powered Flexibility.
Easy-to-operate software control
5.0 EXPERIMENTAL PROCEDURE
1) The design of the product is drawn in Catia software in 3D with the maximum size of 100mm X 100mm.
2) The design was change into drawing sheet. The drawing then saved in .dxf format.
3) The FastCam software then opened, click on “Files” and then click on “DFX Restore” and button “Enter” was clicked. 4) Find the product design in .dxf format and then click the “Select” button. The design then is saved in flash drive. 5) The flash drive that contain the product design is connected to the CNC plasma machine. 6) The coordinate coding system for the product design was transferred to the CNC plasma machine to read. 7) Before cutting process is held, a test to trace the place where to cut the product produ ct was run. 8) When the test was finished, cutting process was started with the speed of 1500rpm.
9) The product then going to cooling process by flowing water onto the product. 10) The product was then went to finishing process after the cutting process is finished where we need to grind the product to make it look good and perfect.
11) The product was sketched on a piece of paper and was brought to metrology laboratory to calculate and measure the area of the product by using digital planimeter.
12) Recorded area is to differentiate the original area of the product and the cutting product produ ct area.
6.0 RESULT & DATA ANALYSIS
3
2
3
1
Figure 14: Final Product
Number of
Types of defects
defects
1
Edge dross
2
Overcut
3
Positive and negative cut angle
6.1
G Codes
G92 X0.Y0. G21 G91 G00 X39.198 Y34.722 G41 M07 G01 Y5. G03 I-7.071 J-7.071 G03 X-7.071 I-3.536 J-3.536 M08 G40 G00 X7.071 Y23.631 G41 M07 G01 Y5. G03 I-7.071 J-7.071 G03 X-7.071 I-3.536 J-3.536 M08 G40 G00 X38.563 Y-24.922 G41 M07 G01 X3.535 Y3.535 G03 X-17.008 Y21.8 I-22.475 J0. G01 Y-43.6 G03 X17.008 Y21.8 I-5.466 J21.8
G03 X-4.999 Y5. I-5. J0. M08 G40 G00 X-70.234 Y-2.395 G41 M07 G02 X4.454 Y14.191 I33.135 J-2.605 M08 G40 G00 Y-33.592 G41 M07 G02 Y33.592 I28.682 J16.796 G02 X28.681 Y13.204 I11.871 J11.966 G02 Y-60. I16. J-30. G02 X-28.681 Y13.204 I-16.81 J1.238 G02 X-4.454 Y14.191 I28.682 J16.796 M08 G40 M02
6.2
Area Measurement of Final Product
Experimental Value
Shape outline
Left Eye
Right Eye
Mouth
Total area
(cm²)
(cm²)
(cm²)
(cm²)
(cm²)
57.8
2.80
2.80
4.30
47.9
58.0
2.79
2.77
4.42
48.02
57.9
2.89
2.87
4.25
47.89
57.8
2.84
2.78
4.32
47.86
Average
47.92
Theoretical Value
Figure 15: Area of the surface by using Measure Inertia in Catia
Total area = 44.12 cm²
6.3
Sample of Calculation
Average value for surface area
= 47.9 +48.02+47.89+47.86 4 = 47.9 47.922 Percentage of error
−ℎ | ×100% = | − 44.1 47.92 cm 44 .12 2 cm = ×100% 47.92 cm = 7.93 93 %
7.0 DISCUSSION
From the experiment we can see see defects that are present present on the final product. Firstly, we have edge dross on the left of the product. This happens because of the CNC machine need to reduce its speed when making acute direction change like right angle. Thickness of the steel plate, the speed of cutting, its ampere also the material composition effects the defects. This is one of the defects that hard to be prevented as it may be reduced by correcting the drawing before cutting. Not just that, on the right top eye side there is overcut. Overcut happens when the CNC machine cut more than it should be cut. In a way which it couldn’t be doing that but that but as a machine it may sometimes have it flaws. Maybe the presets on the machine that caused it to act like that. Other effects maybe the steel plate surface is unsmooth and cause it to effect while cutting. Lastly, some positive and negative cut angle are present on the product. Negative cut angle is when it is smaller which goes undercutting while positive angle when the sample is smaller than bottom. The negative level is caused by slow cutting speed, less torch standoff and high ampere. For positive angle, it may be caused by low amperage, too high torch standoff and shabby nozzle. All the defects caused the product to become imperfect and can be discusses. The area is then calculated and been compared with the theory. The area of the product is 47.92cm2 which is bigger than its theoretical area in the Catiya which is 44.12cm2. Then the percentage error of the area was calculated and got 7.93%. This number shows that the experiment is a quite success as it shows just a little percentage error.
8.0 CONCLUSION
This experiment was a complete success, the conclusion is that we can finally achieved the objectives of the experiment. We get a new knowledge on CNC plasma cutting from its preparation process and its its cutting stage. We can able to know the the types of defects that happens on the product after the experiment. Our products give less defects as the percentage error compared to the theoretical area is less which is less than 10%. CNC plasma cutting is one of the advance machinery that can be used for all engineers and students for easier the works in manufacturing and industries in the future.
9.0 RECOMMENDATION
Calibrate the machine so the presents are not faulty.
Check its torching power before start cutting.
Smoothen the surface before cutting to avoid overcut.
Check the ampere as it could affect the cutting.
Use suitable metal for the process
10.0
REFERENCES
Website
1. Casting Defects. Retrieved from https://www.slideshare.net/BhanuChandar4/casting-procedure-defects 2. Industrial plasma cutting. Retrieved from http://plasmacuttersreviews.com/cnc-plasma-table-reviews/ 3. Industrial plasma cutting. Retrieved from https://hornetcs.com/hornet-lt-cnc-plasma-cutter/ 4. Plasma cutter mechanism. Retrieved from https://torchmate.com/white-papers/How-a-plasma-cutter-works 5. Operation of CNC plasma cutting. Retrieved from https://www.researchgate.net/figure/Parameters-of-CNC-plasma-cutting-machineoperation_fig5_291336407 6. Numerical Control. Retrieved from https://en.wikipedia.org/wiki/Numerical_control 7. CNC machine. Retrieved from https://www.thomasnet.com/about/cnc-machining-45330503.html 8. CNC machine operation. Retrieved from https://www.brighthubengineering.com/manufacturing-technology/55787-what-is-thecnc-machine-how-cnc-machine-works/ 9. CNC milling overview. Retrieved from https://astromachineworks.com/what-is-cnc-machining/ Journal
1. Serope Kalpakjian & Steven R. Schmid, Manufacturing Processes for Engineering Materials, 4th Edition, Illinois Institute Of Technology, Prentice Hall, 2003.
11.0
APPENDICES
