FACULTY OF MECHANICALENGINEERING
UNIVERSITI TEKNOLOGI MARA (UITM)
Program : Bachelor Of Engineering (Hons) Mechanical (EM220)
Course : Manufacturing Process Laboratory
Course Code : MEM564
Laboratory Name : Advanced Manufacturing (Product Quality)
Lecturer Name : Mohamad Firhan bin MorniTitle Of Experiment : CNC Plasma
Group : EMD5M10
No. Student Name Student ID Number Signature
1. Siti Farisyah Binti Mohammad Rafig (K) 2016229512 2. Syazril Hafiz Bin Mohd Sofian 2016229362 3. Syed Saifullah Bin Syed Ali 2017806286 4. Wan Muhammad Fakhrulrazi Bin Wan Zohairi2017665748 5. Zikri Ashraff Bin Zulkepli2017806594 Date of Practical Session Staff Certification (Signature)
Date of Report Submission Staff Certification (Signature)
TOC o “1-3” h z u 1.0 TITLE PAGEREF _Toc526028752 h 22.0 OBJECTIVE PAGEREF _Toc526028753 h 33.0 INTRODUCTION PAGEREF _Toc526028754 h 34.0 APPARATUS PAGEREF _Toc526028755 h 54.1 INDUSTRIAL APPARATUS PAGEREF _Toc526028756 h 75.0 EXPERIMENTAL PROCEDURE PAGEREF _Toc526028757 h 96.0 RESULTS & DATA ANALYSIS PAGEREF _Toc526028758 h 117.0 DISCUSSION PAGEREF _Toc526028759 h 148.0 CONCLUSION PAGEREF _Toc526028760 h 169.0 RECOMMENDATION PAGEREF _Toc526028761 h 1710.0 REFERENCES PAGEREF _Toc526028762 h 18
1.0 TITLEADVANCED MANUFACTURING
( CNC PLASMA )
2.0 OBJECTIVECNC Plasma is used as a tool for cutting a metal for a wide a variety of purpose.
CNC Plasma is used for cutting a simple or a complex shape.
CNC Plasma is also used to direct the machine motion based on numerical codes saved into the program.
3.0 INTRODUCTIONPlasma cutting is a cutting process that is carried out to cut the electrically conductive material. This action is usually executed at very high temperatures involving the melting of metal at the boundary of cutting. The material that are commonly used by plasma cutting machines are such as steel, stainless steel, aluminium, copper and other conducting material. A CNC plasma cutting is a machine that executes the plasma cutting, controlled by a computer. The term ‘CNC’ stands for ‘Computer Numerical Control’ which means that this machine’s operation and movement is directed by computer based on numerical codes of programming saved into the computer system. This machine consists of two parts of the system to operate optimally. The system includes a programming and a drives system. The CNC machine needs programming codes which is the CAD file (CATIA V5) that contains the design of desired product. The design provides the details to the machine and helps it to organize the cutting process by determining the coordinates of cutting to be carried out. CNC plasma machine also contains a drive system where it is responsible to control the mobility and motion of cutting mechanism. The operation of the machine starts with the CNC machine reading and analysing the design from CAD file whether it can be executed or not. This is where the axis of coordinate was set up for the cutting operation. The computer then produces signals to the machine’s drive system to operate. The drive system controls motion of plasma torch based on analysed design at wanted direction and acceleration that we require. This machine has system that controls the input and output commands to make sure it can be operated well to cut the material.
The plasma cutting process goes by forming an electrical channel of high temperature and ionised plasma. Compressed gas at high pressure blows into a torch at high velocity towards the material to be cut. The electrical arc ionized the gas and creates an electrically conductive channel of plasma which produces the electrical torch. The torch of plasma has very high temperature and enough heat energy to melt the contacting part of material. The melting causes the torch to cut through thickness of metal and the hot melted metal is removed by compressed gas. This is how the CNC torch is able to separate the cutting boundaries of the material.
A CNC plasma cutting machine is used widely in industries which has involvement in metal cutting. The usage of this machine depends on the manufacturing environment where it can be means for a few purposes. Usually this machine is involved in department of fabrication, welding, manufacturing and also others.
CNC Plasma Cutting Tools
No Picture Name Function
1. Cnc plasma computer and controller To upload program that needs to be cut using said computer. A controller is used to move the plasma cutter along axis of X and of Y before process of cutting begins.
2. Cnc plasma table To hold a product that needs to be cut. This table is made of durable steel frame that can hold the specific product.
3. Cnc plasma power supply To supply power to cnc torch that can cut the product.
4. Cnc plasma gas To provide fine spray on the cut product to molt a metal in a clean manner with good quality and also to fasten the cutting process.
5. Cnc plasma torch To cut a product with a high current support of gases. Also provides a proper cutting on the product with a stable stand.
4.1 INDUSTRIAL APPARATUSCnc plasma cutter tools are very important to many industries right now. Many kind of advantages are useful to industries today because it is much easier to cut specific metals with a precise and accurate dimension. This cutter can cut a metal with small and large dimension easily because it is with a program that can do it automatically.Some industries use the cnc plasma cutting tools for easier work that can be made, which listed below:Shipbuilding industry· To cut the large piece metal like frame, body and whole of body ship with cnc cutting machine.Figure 1: Ship that needs to be cut and buildSpecialized Industry Like mining recycling and construction industry it work heavily to cut a large metal. With cnc cutting tools work can do better and easily to support human doing extreme heavy work.Figure 2 : Construction metal to cutMetal Art & Custom Industry
Some art and design can be custom using cnc plasma because of by using CAD Drawing people can design and put the program into the machine of cnc plasma. Some complex design can be custom and can be create by cnc plasma.
Figure 3 : Custom art
5.0 EXPERIMENTAL PROCEDUREPrepare beforehand a drawing of a two dimensional (2D) product using Catia V5 and save as .dxf format.
Obtain coordinates of drawing from the system-provided library & save as text document for CNC Plasma Computer to read.
Mount the steel plate onto the CNC Plasma Table.
Save coordinates into the CNC Plasma Computer to check if the graphics display area meets the parameters for cutting process to occur.
Align the CNC controller with the metal plate & test the drawing parameters first.
Then, use the speed of 400 mm/s & press the “Enter” button to start cutting process automatically.
Caution : Do not stand too close to the CNC Plasma Cutting Machine at this time because the sparks can potentially harm you. Put on safety face mask or safety goggles before cutting product!
When complete, repeat steps 5 & 6 with the speed of 450 mm/s.
Collect the two products, proceed with finishing & discuss the results.
6.0 RESULTS & DATA ANALYSIS6.1 Original drawing
Figure 6.1.1 Original drawing for specimen
6.2400 mm/s speed
Figure 6.2.1 Specimen after cutting
Figure 6.2.2 Specimen after finishing
6.3450 mm/s speed
Figure 6.3.1 Specimen after cutting
Figure 6.3.2 Specimen after finishing
6.4 Cutting speed
No. Time (s) Length of cut (mm) Cutting speed (mm/s)
1. 80 300 400
2. 65 300 450
Average cutting speed: 425 mm/s
6.5 Material type
a) Material type: Mild steel
Material thickness: 50mm
Cutting speed: 400 mm/s
No. Defect Reason
1. Several chips at the edge The surface of the object is too hot
2. 3. 4. b)Material type: Mild steel
Material thickness: 50mm
Cutting speed: 450 mm/s
No. Defect Reason
1. Number 7 did not cut or removed The cutting speed is too fast.
2. Chipping at the edge The surface is too hot
3. 4. 6,6 Thickness
No. Cutting speed (mm/s) Thickness (mm) Height (mm) Length (mm) Sides (mm)
1. 0 10.00 77.942 90.00 45.00
2. 400 9.97 76.847 89.25 44.33
3. 450 9.94 76.038 88.89 43.21
7.0 DISCUSSIONIn this experiment, we may discussed about the result of the work piece before and after finishing process, what is the advantages and disadvantages of using CNC plasma cutting and what error that can be made when the experiment is conducted.
There are two results that can be discussed. It is because it has a different cutting speed which the first speed is 400mm/s and the second speed is 450mm/s. In figure 6.2.1, it is shown the result of the work piece after cutting at a speed of 400mm/s. Therefore, it is shown that the number ” 7 ” at the centre is not fully removed. It is because the metal work piece is freshly cut by the CNC Plasma. In figure 6.2.2, it is shown the work piece after finishing process. It is shown after finishing process there are still some metal that is not fully cut by CNC plasma cutting machine. The sides of the hexagon is also not as smooth as the hexagon from the speed of 400mm/s. It is because the cutter of the CNC plasma cutting machine is already worn.
In figure 6.3.1, it is shown the work piece is cut at the speed of 450mm/s. Thus, in figure 6.3.2, it shown the work piece is after finishing process. At the speed of 450mm/s, the work piece is not fully cut after finishing. It is shown that in figure 6.3.2 the shape at the middle of the work piece is not same as result in figure 6.2.2. It is because the machine cannot operate optimally at the speed higher than 400mm/s. Hence, the number ” 7 ” is still attached to the hexagon. It is because the cutter of the machine is already worn and the machine is not maintained very well.
The first advantage of using CNC plasma cutting is it has a high precision and high accuracy. It is because the CNC plasma cuttings is operated in a computer and are paired with state-of-the-art software. Thus, the specification for measurement is already stored in the computer before the cutting process begins. Since the cutter is computer operated, the cuts are sharp and accurate. The second advantage is a quick operation of the machine. The CNC plasma cutting do not require preheating and it can operate instantly. Thus, the cutting speed can operate at high speed cutting which is at 300-450 mm/s. The third advantage is the best aspect for CNC plasma cutting system is safe and secure. It has an exhaust or downward draft system that draws the smoke away from the operator. The function of downward draft system is to constrain all the debris and fumes that produce while cutting.
The first disadvantage of using CNC plasma cutting is hardened edges. The plasma cutter will create a warmed affected region that can produce a hard edge at work piece. Secondly, the disadvantage is the dross that is produced at the edge of the work piece. Lastly, the disadvantage is cost. The cost to maintain the plasma cutter is quite expensive it is because the machine part will become wear at certain times.
There are some errors when the experiment is being conducted which is measurement error. Measurement error that occurred in this experiment when the measurement of the work piece is not same than the measurement in computer drawing. It is because due to the lack of accuracy in CNC plasma cutting machine. It is because the machine is already out of maintenance and the cutter of a machine is already worn out. Thus, the result of the work piece will have a slight difference from the actual value in the computer system. The second error that occurred in this experiment is human error. Observational error occurred due to wrong observation or reading of the instrument. In this experiment it occurred when the reading instrument is used as vernier calliper to measure the work piece and the reading is less accurate. It is because the observers eye is not at position angle measurement marking.
8.0 CONCLUSIONAs a conclusion, CNC Plasma can be used on the two products we want to cut to analyse the surface finishing and result of the product after we cut. CNC Plasma can also be used to cut a complex or simple shape such as our design, a hexagon with a number ” 7 ” at the centre. The result shows that the CNC Plasma can read numerical codes to produce our product. So we can conclude that some metal need to cut with specific velocity to produce a good finishing surface product. One of our product that we cut with 400mm/s speed cutting, we produce a good surface finish of product and nearly accurate as we programmed it. Next product that we cut with 450mm/s speed, some parts of the metal such as the number ” 7 ” is not cut out and the surface of product got some defects on it. So our purpose to determine the defect and error while testing our product cut with 400mm/s speed and 450mm/s speed is accomplished.
9.0 RECOMMENDATIONIn this laboratory session, there were a few recommendation and suggestion in order to improve the result. Firstly, before starting to use the CNC plasma cutting machine, the design of product should be ready and compatible with the machine’s programming system. The machine cannot execute a few design which were too complex, have small lettering and numbering and very small angularity. For a long term, it was recommended to upgrade the machine’s programming to improve the machines ability so that it can read the more complex design and execute the cutting without fail. Secondly, adjust the cut height at appropriate distances. To improve the cutting product, the distance between the torch and the material should be at ideal distance, not too close and not too far. Bottom dross will appear if the cutting carried out at a very close distance while spatter will produce at the top of cut if the torch was too far. It also recommended to control the speed of cutting. In this laboratory experiment, we can see the difference of results between the different speeds of cutting. The cutting that was carried out at a faster speed produced a defect product where the cutting was incomplete. Undesired part that should be removed could not be separated. The torch of machine only cut half of the thickness of the metal where the upper side was cut while the bottom side was still in contact with the product. To prevent this problem, the cutting should be executed at appropriate speed and at least slower than the speed that is being used in our experiment. Besides, include a cooling procedure or process. After finishing the cutting process, the product material was at high temperature because of the heat energy from the torch transferred to the metal product and consumes much time to be cooled. That makes the other procedure which was the finishing process to be delayed. It was suggested that the cooling procedure include in this session where the product can be cooled faster and reduce cooling time so that the other procedure can be done. In industry, time consuming was one of the crucial aspect where the product must be produced at good quality and shorter time.
10.0 REFERENCES5 Businesses That Use CNC Plasma Cutting. (2018, July 10). Retrieved September 30, 2018, from https://www.ezcutcnc.com/5-businesses-that-use-cnc-plasma-cutting/
Advantages of CNC Plasma Cutting. (n.d.). Retrieved October 2, 2018, from https://www.plasmacnc.co.uk/blog/advantages-of-cnc-plasma-cutting/Basic Tips to Improve Plasma Cutting Performance. (n.d.). Retrieved September 30, 2018, from https://www.millerwelds.com/resources/article-library/basic-tips-to-improve-plasma-cutting-performance?_e_pi_=7,PAGE_ID10,6957770169CNC Plasma Cutting in Various Industries | Messer Cutting Systems. (2018, June 14). Retrieved September 28, 2018, from https://www.plasmacuttingpros.com/industries/CNC Plasma Cutting Machine Operational Manual. (2018, July 17). Retrieved September 29, 2018, from https://www.machinemfg.com/cnc-plasma-cutting-machine-operational-manual/Elektronik, A. (n.d.). Retrieved September 30, 2018, from https://www.ajancnc.com/en-us/cncplasmacuttingmachine.php?_e_pi_=7,PAGE_ID10,4292461235Home. (n.d.). Retrieved October 2, 2018, from https://www.everlastgenerators.com/blog/pros-and-cons-cnc-plasma-cutterHow a plasma cutter works. (n.d.). Retrieved September 30, 2018, from https://torchmate.com/white-papers/How-a-plasma-cutter-worksTen Tips for Improving Plasma Cutting Quality. (n.d.). Retrieved September 30, 2018, from https://www.millerwelds.com/resources/article-library/ten-tips-for-improving-plasma-cutting-quality?_e_pi_=7,PAGE_ID10,3046796667Wallulis, K. (2018, April 30). How to Prevent Parallax Error. Retrieved October 2, 2018, from https://sciencing.com/prevent-parallax-error-10000073.htmlWhat is a CNC plasma cutter? (n.d.). Retrieved September 30, 2018, from http://www.esabna.com/us/en/education/blog/what-is-a-cnc-plasma-cutter.cfmWhat is a CNC Plasma Cutter and How Does it Work? (2015, December 11). Retrieved September 30, 2018, from http://www.cnc.com/what-is-a-cnc-plasma-cutter-and-how-does-it-work/