NTM 2 complete.docx

1.0 TITLE CNC Milling (Non Traditional Machining)

2.0 OBJECTIVE a

To design a basic NC program for CNC Milling.

b

To machine a product using the CNC Milling.

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3.0 INTRODUCTION 3.1 Background Non-traditional manufacturing processes is defined as a group of processes that remove excess material by various techniques involving mechanical, thermal, electrical or chemical energy or combinations of these energies but do not use a sharp cutting tools as it needs to be used for traditional manufacturing processes. Extremely hard and brittle materials are difficult to machine by traditional machining processes such as turning, drilling, shaping and milling. Non-Traditional Manufacturing Processes or non-conventional Manufacturing processes mostly remove material in the form of chips by applying forces on the work material with a wedge shaped cutting tool that is harder than the work material under machining condition. CNC milling is a specific form of computer numerical controlled (CNC) machining.Milling itself is a machining process similar to both drilling and cutting, and able to achieve many of the operations performed by cutting and drilling machines. Like drilling, milling uses a rotating cylindrical cutting tool. Generally CNC milling process has 3-axes to find it coordinate. It represent by the alphabet X,Y and Z. These devices are extremely useful because they are able to produce shapes that would be nearly impossible using manual tooling methods. Some advantages of this type of machine are that it is automatically cool down. It is also very precise with typically 0.0001 inch. It is also easy to multiply copies, easy to create similar object and need fewer worker to handle it

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Figure 3.1: CNC milling machining CNC milling devices are also the most widely used type of CNC machine. Typically, they are grouped by the number of axes on which they operate, which are labeled with various letters. X and Y designate horizontal movement of the work-piece (forwardand-back and side-to-side on a flat plane). Z represents vertical, or up-and-down, movement, while W represents diagonal movement across a vertical plane. Most machines offer from 3 to 5 axes, providing performance along at least the X, Y and Z axes. Advanced machines, such as 5-axis milling centers, require CAM programming for optimal performance due to the incredibly complex geometries involved in the machining process. These devices are extremely useful because they are able to produce shapes that would be nearly impossible using manual tooling methods. Most CNC milling machines also integrate a device for pumping cutting fluid to the cutting tool during machining.

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3.2 Theory Common G codes and M codes for CNC machine controls CNC G codes G00 - Positioning at rapid speed; Mill and Lathe G01 - Linear interpolation (machining a straight line); Mill and Lathe G02 - Circular interpolation clockwise (machining arcs); Mill and Lathe G03 - Circular interpolation, counter clockwise; Mill and Lathe G04 - Mill and Lathe, Dwell G09 - Mill and Lathe, Exact stop G10 - Setting offsets in the program; Mill and Lathe G12 - Circular pocket milling, clockwise; Mill G13 - Circular pocket milling, counterclockwise; Mill G17 - X-Y plane for arc machining; Mill and Lathe with live tooling G18 - Z-X plane for arc machining; Mill and Lathe with live tooling G19 - Z-Y plane for arc machining; Mill and Lathe with live tooling G20 - Inch units; Mill and Lathe G21 - Metric units; Mill and Lathe G27 - Reference return check; Mill and Lathe G28 - Automatic return through reference point; Mill and Lathe G29 - Move to location through reference point; Mill and Lathe (slightly different for each machine) G31 - Skip function; Mill and Lathe G32 - Thread cutting; Lathe G33 - Thread cutting; Mill G40 - Cancel diameter offset; Mill. Cancel tool nose offset; Lathe G41 - Cutter compensation left; Mill. Tool nose radius compensation left; Lathe G42 - Cutter compensation right; Mill. Tool nose radius compensation right; Lathe G43 - Tool length compensation; Mill G44 - Tool length compensation cancel; Mill (sometimes G49) G50 - Set coordinate system and maximum RPM; Lathe G52 - Local coordinate system setting; Mill and Lathe G53 - Machine coordinate system setting; Mill and Lathe G54~G59 – Work piece coordinate system settings #1 t0 #6; Mill and Lathe G61 - Exact stop check; Mill and Lathe G65 - Custom macro call; Mill and Lathe G70 - Finish cycle; Lathe G71 - Rough turning cycle; Lathe G72 - Rough facing cycle; Lathe G73 - Irregular rough turning cycle; Lathe G73 - Chip break drilling cycle; Mill G74 - Left hand tapping; Mill G74 - Face grooving or chip break drilling; Lathe G75 - OD groove pecking; Lathe G76 - Fine boring cycle; Mill 4

G76 - Threading cycle; Lathe G80 - Cancel cycles; Mill and Lathe G81 - Drill cycle; Mill and Lathe G82 - Drill cycle with dwell; Mill G83 - Peck drilling cycle; Mill G84 - Tapping cycle; Mill and Lathe G85 - Bore in, bore out; Mill and Lathe G86 - Bore in, rapid out; Mill and Lathe G87 - Back boring cycle; Mill G90 - Absolute programming G91 - Incremental programming G92 - Reposition origin point; Mill G92 - Thread cutting cycle; Lathe G94 - Per minute feed; Mill G95 - Per revolution feed; Mill G96 - Constant surface speed control; Lathe G97 - Constant surface speed cancel G98 - Per minute feed; Lathe G99 - Per revolution feed; Lathe CNC M Codes M00 - Program stop; Mill and Lathe M01 - Optional program stop; Lathe and Mill M02 - Program end; Lathe and Mill M03 - Spindle on clockwise; Lathe and Mill M04 - Spindle on counterclockwise; Lathe and Mill M05 - Spindle off; Lathe and Mill M06 – Tool change; Mill M08 - Coolant on; Lathe and Mill M09 - Coolant off; Lathe and Mill M10 - Chuck or rotary table clamp; Lathe and Mill M11 - Chuck or rotary table clamp off; Lathe and Mill M19 - Orient spindle; Lathe and Mill M30 - Program end, return to start; Lathe and Mill M97 - Local sub-routine call; Lathe and Mill M98 - Sub-program call; Lathe and Mill M99 - End of sub program; Lathe and Mill

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4.0 APPARATUS

Cutting tool Holding workpiec e

Work piece

Figure 4.1: CNC Milling machine with parts labelled

Machine controller

Figure 4.2: Machine Controller

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4.1

INDUSTRIAL APPARATUS

1.

Figure 4.1.1: Okuma MA650VB 50 Taper (aerospace parts) -50-taper CNC mills that deliver 800 foot-pounds of torque for heavy duty materials like titanium, invar, and Inconel.

2.

Figure 4.1.2: Mori Seiki MV Junior CNC Mill (automotive parts) 7

- Creating new and recreating old race car components requires the equipment that takes raw material stock and transforms it into the component needed on the car. 3.

Figure 4.1.3: Micro grinding reminiscent of Swiss-type machine (medical parts) -

The medical field uses CNC milling machines to build customized precision parts such as prosthetic knee and hip replacement joints, mold cavities and cores, specialized tools and equipment for surgery, and more.

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5.0

EXPERIMENTAL PROCEDURE

1. The work piece is prepared as shown in the figure 5.1.

Figure 5.1: work piece of wooden block 2. The pattern is designed in computer by using software CATIAV5 and a writing is created on the work piece (in computer). 3. The coding (program) is generated to enable the CNC milling machine read the program and doing the milling processes. 4. The coding (program) which generated by the computer is transferred and uploaded to the CNC milling machine and the CNC milling machine now enables read the coding. 5. The work piece now is placed on the workplace and is clamped by a clamp attached on the CNC milling machine. 6. The path which travelled by the edge of the drill of the CNC milling machine is set up in the machine before the starting the machining process.

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7. The datum in direction x, y and z is set up by hitting the drill to the work piece a little as shown in figure 5.2 and then the datum is set up in the machine.

Figure 5.2: shows how to make a datum on the work piece before datum is set up in the CNC milling machine

8. The milling process is started by pushing start button and the thickness of the work piece is changed from 20mm to 15mm and then milling process is continued until it is the milling process is finished. 9. The work piece now is taken and ready to be observed.

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6.0

RESULTS AND DATA ANALYSIS

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INTELLIGENT MANUFACTORY SOFTWARE WWW.IMS-SOFTWARE.COM

(*

IMSPOST VERSION : 7.4R

(*

USER VERSION : 1

*) *)

( ********************************************************************** ) N1 G49 G64 G17 G80 G0 G90 G40 G99 ( TOOL DATA : T1 END MILL D 1 ) N2 T0001 M6 N3 X12.266 Y24.091 S70 M3 N4 G43 Z10.01 H1 N5 G1 G94 Z.01 F300. N6 X12.173 Y24.364 Z-.067 N7 X11.959 Y24.811 Z-.2 N8 X11.927 Y24.863 F1000. N9 X11.996 Y24.705 N10 X12.019 Y24.646 N11 X12.164 Y24.189 N12 X12.179 Y24.133 N13 X12.284 Y23.639 N14 X12.295 Y23.573 N15 X12.371 Y22.809 N16 X12.374 Y22.741

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N17 X12.363 Y21.982 N18 X12.358 Y21.913 N19 X12.274 Y21.268 N20 X12.331 Y21.458 N21 X12.425 Y21.942 N22 X12.474 Y22.464 . . . N9276 X59.706 Y31.996 N9277 X59.747 Y31.963 N9278 X59.767 Y31.945 N9279 X59.941 Y31.759 N9280 X59.958 Y31.738 N9281 X59.99 Y31.695 N9282 X60.004 Y31.672 N9283 X60.131 Y31.431 N9284 X60.137 Y31.419 N9285 X60.148 Y31.394 N9286 X60.153 Y31.382 N9287 X62.803 Y24.125 N9288 X62.805 Y24.121 N9289 X62.808 Y24.112 N9290 X62.809 Y24.107 N9291 X62.833 Y24.032 N9292 X62.837 Y24.016 N9293 X62.845 Y23.984 N9294 X62.848 Y23.968 N9295 X62.885 Y23.701 N9296 X62.887 Y23.674 12

N9297 X62.888 Y23.619 N9298 X62.886 Y23.592 N9299 X62.851 Y23.324 N9300 X62.846 Y23.297 N9301 X62.831 Y23.245 . . .

N9992 X55.293 Y22.163 N9993 X62.441 N9994 X62.46 Y22.162 N9995 X62.652 Y22.144 N9996 X62.701 Y22.133 N9997 X62.98 Y22.033 N9998 X63.019 Y22.014 N9999 X63.188 Y21.908 N1 X63.227 Y21.876 N2 X63.403 Y21.69 N3 X63.434 Y21.647 N4 X63.565 Y21.404 N5 X63.575 Y21.381 N6 X64.405 Y19.2 N7 X64.826 Y18.217 N8 X65.018 Y17.847 N9 X65.11 Y17.732 N10 X65.25 Y17.671 N11 X65.453 N12 X65.594 Y17.715 N13 X65.738 Y17.824 13

N14 X65.861 Y17.981 N15 X65.889 Y18.057 N16 X65.886 Y18.187 N17 X65.81 Y18.52 N18 X65.546 Y19.277 N19 X63.912 Y23.316 N20 X64.004 Y23.353 N21 X64.096 Y23.391 N22 X61.032 Y30.958 N653 X62.187 Y22.925 N654 X61.965 Y22.76 N655 X61.724 Y22.669 N656 X61.49 Y22.64 N657 X56.241 N658 X56.159 Y22.643 N659 X55.919 Y22.694 N660 X55.67 Y22.813 N661 X55.481 Y22.983 N662 X55.329 Y23.213 N663 X55.248 Y23.467 N664 X55.237 Y23.744 N665 X55.292 Y23.982 N666 X57.894 Y31.237 N667 X58.031 Y31.494 N668 X58.216 Y31.686 N669 X58.448 Y31.824 N670 X58.71 Y31.895 N671 X58.965 Y31.893 N672 X59.226 Y31.823 N673 X59.381 Y31.813 Z-.958

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N674 X59.529 Y31.863 Z-.916 N675 X59.647 Y31.965 Z-.874 N676 X59.716 Y32.105 Z-.832 N677 Z9.168 N678 G0 Z10. N679 M5 N680 M30 N681 M2 N682 M30 %

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Step 1

Step 2

Step 3

Figure 6.1: Process through CNC milling machine

7.0

DISCUSSION OF RESULTS

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In this experiment, our aims are to learn and understand the use and capabilities of computer numerical control (CNC) milling machine.There are three ways to get the NC program which is APT , manual and (CAD). In this experiment, we were teach to used CAD as to find and develop the NC program. CAD is used to make a design of a product. In CAD, it involves a special symbolic programming languages or codes that determine the coordinate points of corner, edges and surfaces of the work piece. Once the design is completed, we supposedly transfer the coding that we made using ISO NC programmed to the CNC milling machine. All the data about the process from the beginning to the end is included in those codes and wrong coding will damage the work piece. After finish the design by using CAD, . we transfer the NC program to the (CNC) milling machine to proceed our design on the surface of the work piece. In order to prevent damage, we need to view the simulation on the CNC screen and do some final editing so that the milling machine is operating in a good condition as we will obtain perfect work piece.. The machines cutting tool might break. We have to set up cutting tool, cutting fed, cutting speed , spindle speed that is suitable with the specimen to avoid error occur during the process. From the experiment, we can say that our product is perfect and thus our experiment is consider to be success. The process of CNC milling machine show that, there are lot advantages to produce any product with the help of CAD as a design and produce the right NC program. Furthermore, training in the use of CNCs is available through the use of ‘virtual software’, this software that allows the operator to practice using the CNC machine on the screen of a computer. Design changes are almost easier to amend because it can be done by make simple adjustment at the CNC program. Finally, this machine is easy to operate which key in the coding to operate.

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8.0

CONCLUSION Based on the experiment, all objective that we coincide to design a

basic NC program for CNC milling and to machine a product using the CNC milling before doing the experiment are achieved.. We consider that both of the NC programming and CNC Milling Machine were used to produce the desired products. There are some defects will occur to the desired product, it depend on the types of design. The sharp or edges product can’t be proceed because it will effect the surface of the product which is not completely follow the design. Students who are following the experiment can also see with their eyes how to do CNC milling processes while practicing safety precaution before do the machining processes. This experiment also can improves their understanding about the CNC milling and they can use the knowledge that they learn from this session in real engineering world to become succesful engineers. Students also can appreciate the knowledge that they learn from this lab session. The use of CNC help the process to run smoothly and provide other advantages. It improves automation, removing the need of an operator for all but a few parts of the work. CNC machines can be left unattended for hours or even days if necessary, allowing operators to focus on other tasks. CNC machines can be used continously 24 hours a day, 365 days a year and only need to be switched off for occasional maintenance. But this technology is costly and not suitable for small scale production.

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9.0 RECOMMENDATION

One of the recommendation is make sure the speeds and feeds are consistent to increase the quality of the CNC milling machine and will produce a huge difference on the surface finish. Getting the right speeds and feeds is just as important to obtain a good surface finish. Sometimes as the work piece is heated up, it will affected due to thermal expansion. As the coolant cools the tools it also cools the work piece and this can increase the accuracy as the work piece produce good surface finish. Beside that, coolant also act as lubrication for the tool and work piece interface. All the tools should be kept clean and well maintained. The machining tools can be maintain by applying oils to make sure no rusting part. After using the tools, students should clean the used tools to keep the

cleanliness

of

the

tools.

Next

recommendation

is

laboratory

cleanliness. The laboratory should always be keep clean and tidy. The floor should be clean and make sure that there is no other material that can cause to a disaster in the lab. Other recommendation is lecturer and technician should provide a simple instruction on carry out the experiment. The instruction for designing the product and procedure on using the machine and other equipment should be clear and understandable so that the students could 19

run the process according to the instructions prepared even without guide from the lecturer. Students also should prepared before entering the laboratory by study the lab sheet given and any information about the experiment so that it is easier for lecturer and also students to conduct the experiment when the students understand what they are doing. These improvements and recommendations could make the students learn more about the process and could gain themselves a lot more information about the experiment which can provide them more knowledge that can be use in industry.

10.0 REFFERENCES 1. Mike Mattson, CNC Programming: Principles and Applications, Delmar, Cengage Learning, CliftonPark, New York, 2010. 2. Milling(machining). Retrieved November 20, 2016, from Wikipedia https://en.wikipedia.org/wiki/Milling_(Machining) 3. Mikell P. Groover, Principles of Modern Manufacturing, 4thEdition, Wiley 2011 4. Ostwald, P. F., and J. Munoz, Manufacturing Processes and Systems, 9 th ed. John Wiley &Sons, New York, 1997. 5. Kalpakjian, S., and Schmid S. R. Manufacturing Processes for Engineering Materials, 5thed. Pearson Prentice Hall, Upper Saddle River, New Jersey, 2007. 6. Kardes, N., & Altintas, Y. (2007). Mechanics and dynamics of the circular milling process. Journal of Manufacturing Science and Engineering, 129(1),21.

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7. Machining

Retrieved

November

20,

2016,

from

Wikipedia,

https://en.wikipedia.org/wiki/Machining. 8. Werner, A., & Poniatowska, M. (2015). Improving accuracy of curvilinear

profiles

machined

on

CNC

milling

centres.

Mechanik725/338-725/346. 9. Hitomi, K. (1996). Manufacturing systems engineering: A unified approach to manufacturing technology, production management and industrial economics (2nd ed.) Bristol, PA: Florence, Kentucky, USA,: Taylor & Francis. 10. Mazumdar, S.K. (2001). Composites manufacturing: Materials, product and process engineering, Boca Raton, FL: Taylor & Francis.

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