Computer-Aided Design Essay Example

Computer-Aided Design

Manufacturing using CAD/CAM

CAD stands for Computer-Aided Designs, while CAM stands for Computer-Aided Manufacturing. The two refer to using computer software that is used in designing and also manufacturing of products. Designers will use CAD to design models as well as documentation. Computer numerical control machining is a common CAD/CAM application where it helps in the process of program manufacturing and also in designing a given product.

Application of CAD/CAM in the process of manufacturing has a lot of significance in the manufacturing industry. Using CAM/CAD software makes it easy to confirm the tool paths prior to material cutting. During manufacturing, it is important to reduce and minimize wastes and scraps. Using these systems ensures that there is complete machining through simulation. This will also reduce maintenance cost since there is reduced tool wear. It will also result in less energy consumption. It is easy to identify the time needed for a product to be manufactured. This is can be achieved with the help of CAD/CAM simulation which is a useful tool in the planning of material supply, material delivery. It is also used in scheduling process (Schievink, & Roiter, 2005). Using CAD in designing a model, it is possible for an individual to maintain the desired dimensional accuracy. This is because the system enables a 3D representation of a model.

Designers and manufacturer are able to design models easily and fast with the help of 3D CAD. This will ensure that they produce the products timely and accurately. It is also possible to receive or access data from any part of the world. This is because CAD data can be easily sent from one producer to the other with the help of a computer.

Task A) calculate the speed and feeds for a 10 mm four flute short end mill

The following are needed in calculation of speed and feeds

N= the total number of flutes (cutting edges)

Cpt= chip per teeth (chip load) it is also referred to mm per teeth. It will represent the actual amount of material each cutter’s teeth can remove during its rotation.

RPM= this is the revolution per minute. This indicates the cutter’s revolution speed within its spindle.

Therefore provided the following information;

Diameter of the flute= 10mm

Feed per teeth (IPT) = 20

Cutting speed= 23*12= 276

Cutting feed (SFM) = 10*4= 40. 0000

Total diameter = 22/7* 10= 31.4286

Spindle speed (RPM) = cutting speed*total diameter

= Feed rate (IPM) = feed per teeth*spindle speed

= 351.414

Cutting time = cutting length/feed rate

10/351.414

Task 1 B. Using correct tool path strategy; apply planar machining to achieve good surface finish

CAM/CAD system offers an advantage of a high-speed machining. This is of great importance to the computer numerical control. Using planar in slicing the chips is more advantageous since one can easily choose the direction of the cut. It is also possible for someone to determine the parameter of the Lace Angle. While applying planar, the designer is given a chance for side and bottom allowance while cutting the material. This is meant to ensure that there are some materials left for the finish pass. The screenshots bellow indicates aggressive setups useful in machining scenarios. The material chosen for the set up are aluminum, TiAIN ½ “and 3-flute end mill. A tool path also known as cutter path can be described as the actual path taken by the cutting tool as they machine the part. Using a machining wizard will help an individual set r the best machining strategy with a click of a button making it easy to save the data required in making an accurate tool path. It is important to identify the part one want to apply the tool path since there are different tool paths which are suitable for different parts. It is also important that the cutting pattern is identified. The pattern can be either zigzag or single direction cutting, one should also consider custom tolerance factor, roughing parameters, tool path linking and the cut-depth options. In case one wish to alter the tool path to regenerate it, it is possible since one will edit the saved path tool.

Computer-Aided Design

Figure 1a

In the figure above, a clear indication of how the drawing starts is illustrated. It is a guide on how the process starts; the starting point is sketching the program background followed by its layout.

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Figure 1b

In figure 1.2, a 3 D presentation of the object is given. The designers are in a position to get a clear view of the product they are to manufacture.

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Figure 1c

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Figure 1d

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Figure 1e

Figures 1d- 1e shows the front and the side views of the product to be manufactured. This is well illustrated by the use of a 3D representation. In order to achieve the desired product then it is required that high level of accuracy be maintained. In this case, therefore, CAM/CAD uses encoded geometrical data. This makes is for the manufacturing process as well as the process of design integration. In order for the process to be successful and effective, simple wizards are used in order to drive the milling machines in different phases.Computer-Aided Design 5

Figure 1f

Figure 1f shows tool selection as guided by the use of CAD/CAM. As discussed earlier, CAD/CAM are useful tools in the process of manufacturing. After getting full information on how the model will look like it is important that the designer identifies the right tools to use. CAM is a program that will get the actual movement of the applicable tool into the material used through calculations. The program will produce a value of maximum efficiency. In some advanced CAM program, they offer a simulation the shape of the material after cutting it with the chosen tool. While choosing the tools to use it is important to consider a tool crib which is available in the system.
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Figure 1g

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Figure 1h

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Figure 1i

The figures 1f -1i indicates cut specification. In the designing process, it is important to come up with the accurate cut specification. This will ensure that the products are of higher quality and that they meet the required expectations of the designer. It is therefore important to ensure that the parameters are well specified, the designer should also consider the type of cutter to use and how effective it is in accordance with the model in question.

Step over

Computer-Aided Design 9This will refer to both the cut width and cut depth. These are very important parameters in facing, profiling, and pocket milling among other crucial machining operations. The parameters are useful when analyzing the speed and feed. This is because they will help in the determination of the rate of material removal; determination of material removal rate will help in the determination of the time the operation will take before it is complete. By determining the material removal rate with a known machinability it becomes easier in determining the required spindle power for the operation. This will also help in the determination of potential tool deflection. In the case of high tool deflection, then the following will be the negative impacts, poor surface finish, wearing of the tool leading to short tool life, and inaccurate cuts will be realized.

Figure 1.10

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Figure 1.11

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Figure .1.12

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Figure 1.13

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Figure .1.14

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Figure 1.15

The diagrams above from 1.0 to 1.5 are illustrations of different cutting width and cutting depth. Application of the G-wizard Optimizer will allow you to optimize one of the two variables, holding the other variable constant. The optimizer operates by calculating the deepest cut possible that can be made of a material with the tool not deflected (Durrieu et al. 2010). Application of the G-Wizard optimizer will ensure that the data obtained is accurate and reliable and will also ensure that tool deflection is minimized.

Feeds and speeds

In machine tools, these two parameters are used to refer to velocities within the machine tool. The two are always considered as a pair since they work together and they contribute to a combined effect. Speed in other terms can be referred to as; cutting speed or surface speed. This is the relative velocity between the workpiece surface and the speed of the cutting tool. It is given in meters per minute. The feed can also be termed as feed rate. It is the relative velocity of the cutter advancement along the workpiece surface. In the calculation of the speed and feed, G-wizard is very useful. On is required to have full information on the feed rate and the speed. Following the wide range of data available, the designers are to have clear information on what he/she is expected to partake.Computer-Aided Design 15

Figure 1.6

Tool life

Tools can be ranked as either conservative end tools or, Aggressive end tools, with the conservative end tool having much of its emphasis on Surface Finish and Tool Life. Tool should be well handled in order to reduce the rate at which they will wear and tear. It is important to minimize the risk associated to rubbing, for example in gas pedal which is one of the tools used in manufacturing process. This is because rubbing causes friction that results to tear and wear and may reduce the tool life. It is important to note that mostly, rubbing will occur where the speed is low and it is therefore important to maintain high speeding machines. On the other hand, the Aggressive end stresses on the rate of material removal.

Cutting parameters column

The figures 1.17-1.21 deal with cutting parameters.

Surface speed (SFM or SMM); it indicates the speed of a certain tool in relation to the needed cut of a material. The SFM and SMM are parameters which are measured and also denoted per minute. SFM means Surface Feet per Minute while SMM stands for Surface Meters per Minute. These parameters are crucial in that SFM helps in determination of the tool life of the tool in question. In case the recommended SFM is exceeded then the tool is wearing out, and as a result, the tool life is reduced. On the other hand, when the tool wears at a slower rate than that of the recommended SFM the tool life will have a longer tool life.

IPT, this stands for Inches per Revolution; during the process of AFPT and chips thinning, the mill cutter’s screen is expected to be at a machine of high speed, however, it should be noted that the high speed does not greatly influence machine operations. Thinning of the material will mostly occur in case the diameter of the slices is either ½ or less that of the radial engagement. The reason for thinning is because the chips are not sliced to the recommended thickness. The main reason for such setting is in order to come up with a feed rate such that the chips can be repeatedly sliced into full thickness. The machine can be either turn off or on by the use of Chip Thinning. In order to reduce wearing of the slicer, it is advisable that one has to slice the recommended thickness of the chips. This will ensure that the slicer has a long life. The recommended thickness is achieved via bumping heating.

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Figure 1.17

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Figure 1.18

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Figure 1.19

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Figure 1.20

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Figure 1.21

In conclusion, it is clear that there is a difference between the current CAM system and the older numerical control. The differences in the two systems are based on geometrical data. It is also important that one should understand that the geometrical data are mechanically encoded and that CAM and CAD apply techniques based on a computer in encoding the data. Computer- Aided Design will involve designing of models by the use of a computer with the help of geometrical parameters. The CAD models will be presented on the computer monitor on a 3-D representation making it easier for the designer to view the object in a number of representations. It is also easier to alter the designed models through changing the geometrical parameters relevant to the model (Lieberman, 2007).

In cutting parameters, SFM will indicate the speed of the tool used in relation to the cut of the material needed. SFM will determine the life of the tool. In case wearing of the tool is above the set SFM then the tool life will be reduced. Contrary, if the wearing rate of the tool is below the recommended SFM, then the tool life will be long. It is important to slice the chips according to the recommended thickness and also consider the diameter of the chips before slicing. In case the diameter of the chips is either ½ or below that of the radial engagement the chips will be thinned. The slicer will be subjected to wearing in case of slicing thin chips. This will, as a result, reduce its life span.

References

Durrieu, F., Samejima, K., Fortune, J.M., Kandels-Lewis, S., Osheroff, N. and Earnshaw, W.C., 2010. DNA topoisomerase IIα interacts with CAD nuclease and is involved in chromatin condensation during apoptotic execution. Current Biology, 10(15), pp.923-S2.

Lieberman, H. ed., 2007. Your wish is my command: Programming by example. Morgan Kaufmann.

Schievink, W. and Roiter, V., 2005. Epidemiology of cervical artery dissection. In Handbook on Cerebral Artery Dissection (Vol. 20, pp. 12-15). Karger Publishers.