Measurement Using a Digital Micrometer - Lab Report Example

Laboratory 1 - Measurement Name: Registration no: University: Course: Code: Lecturer: Introduction When measuring dimensions, it entails measuring width, length and height of the component in question. To measure these features, there are measuring devices that have the ability to measure such diverse sizes in different parts. In this experiment, we will use digital micrometre to measure the length and the diameter of aluminium pins for production (see figure 1). Thus, since accuracy is of more important is measuring the dimensions of the pins, a digital micrometre was used in this experiment to ensure that the recorded dimensions are as accurate as possible. In most cases where there are various measuring tools, there are cases of errors that are due human observation (Barbato, Germak, and Genta, 2013, 40). Therefore, it is required that such tools produce data that must be averaged to get results that are almost equivalent to the actual measurement of the component. Figure 1: Dimensions for Aluminium Pin for Production Measurement using a digital micrometer In this experiment, we arranged the aluminium in three columns A, B and C of test specimens, where every column had five samples (see figure 3). Then we measured lengths and diameters for the samples and recorded them as X-axis for the diameter and Y-axis for the length (see table 1). Figure 2: Aluminium Pins Figure 3: Aluminium Pins arranged in columns To acquire accurate results from specimen the measurements we used a digital micrometre whose length was 25mm and maximum of 50mm given as the default measurements (see figure 4). Figure 4: 25 to 50 mm micrometer It is important to set the micrometre scale to zero so that it can start from 25mm, which is a process done before starting the experiment. Figure 5: Setting micrometer to start at 25mm We press set button on the micrometre after ensuring that the specimen is well fitted in the micrometre jaws, by scrolling until it reaches 25mm. Having set the micrometre, we then start the taking measurements for the sample and recorded the results in a data (see Table 1). For every specimen, we used a different digital micrometre, repeated the same measurement procedure, and recorded the results for comparison and analysis. Figure 6: 0 to 25 mm micrometer   column A   column B   Colum C Specimen X-Axis Y-Axis Specimen X-Axis Y-Axis Specimen X-Axis Y-Axis 1 5.053 27.544 11 5.047 27.526 21 5.059 27.516 2 5.062 27.518 12 5.060 27.429 22 5.057 27.527 3 5.074 27.462 13 5.031 27.456 23 5.057 27.439 4 5.060 27.447 14 5.058 27.408 24 5.066 27.513 5 5.059 27.526 15 5.077 27.479 25 5.059 27.512 6 5.082 27.340 16 5.058 27.481 26 5.051 27.461 7 5.067 26.278 17 5.063 27.432 27 5.075 27.507 8 5.050 27.361 18 5.071 27.520 28 5.061 27.216 9 5.058 27.525 19 5.073 27.517 29 5.065 27.459 10 5.065 27.428 20 5.057 27.448 30 5.059 27.377 Mean 5.063 27.343   5.060 27.470   5.061 27.453 Range 0.032 1.266   0.046 0.118   0.024 0.311 Table 1: specimen data for lengths and diameters We used the data collected for lengths and diameter for the specimen to determine the mean value for both width and length by adding the values in every column and divide by 10-specimen test. On the other hand, when determining the range of the two variables, length and diameter of the specimen, we calculated the difference between the maximum value and the min value for all variables length and diameter respectively (Morris, 2001 423). When measurements are done, there are experimental uncertainties that may occur during the measuring procedure. Thus, due to these uncertain occurrences, we calculate the mean value from the data and compare this with the actual value so that we can determine which measured value is more accurate. Moreover, it is important to determine the amount of error that was recorded during the experiment. Therefore, range was calculated to determine the amount of experimental error recorded from the experiment to determine the amount of discrepancy between the accurate value and the measured value. Consistency and repeatability is very important when measuring with micrometres, which must be keenly observed to ensure that the experimental data is more close to the true value. For example, range in column A for diameter (X-axis) is 0.032 and that in column C is 0.024 this means that the recorded data is ± that range. In this case data in column C had a large discrepancy and hence a larger amount of error than the other columns. Measurements using a Digital Vanier calipers In this section, we measure a vee block using Vanier callipers. Figure 7: an assembly of a Vee block First, to measure the vee block alone, we separate the model and dismantle the component to get individual components. Figure 8: Separated components of a Vee block Secondly, we utilized a Vanier calliper to evaluate the component measurements Figure 9: Digital Vanier Calipers When measuring internal and external sections of any given component and the data required must be very accurate, we use a digital Vanier callipers to get such measurements. However, it is necessary to make sure that the Vanier scale is set to zero prior to starting the measurements. The digital callipers has a display screen where the resulting measurements are displayed. External features of any given component are measured using the lower jaw of the Vanier calliper while the upper jaw is measures the internal dimensions of the part. In case there is a need to adjust the calliper, the roller on the lower side is used for adjustments. Thirdly, we drew sketches showing the required measurements for the vee block design as shown in figure 10. Figure 10: Vee block labeled sketches However, we face some challenges when determining the curve angle from the U-shape, but we used a compass to draw the angle and determine the radius. Figure 11: Determining the radius of the curves On completing the sketches, we used CAD SolidWorks program the create the final drawing, which indicated spare parts of the vee block then we assembled the parts in one drawing. Then we dimensioned the design using third angle projection BS888 as shown in figure 12. Figure 12: solid works drawing with the assembled drawing We used A4 paper and 1:2 scale for the CAD drawing of the component as shown in the above figure. Figure 13: U-shaped component The U-shape was dimensioned using SolidWorks CAD program; then we drew the locking pin in third angle projection using SolidWorks CAD program (see figure 13). Figure 14: Locking pin component Coordinate measuring machine Measurement using Coordinate Measuring Machine (CMM) In this experiment, we used Kemco Kadet Coordinate Measuring Machine to measure the dimension of the experimental component. The CMM device is shown in figure 15 below and uses a program installed in a computer. Figure 15: Coordinate Measuring Machine (CMM) Measurement procedure: a. Depending on the points to be measured, we procedurally place the component on the machine table and then run the program. b. We allow the machine to touch the component edges to identify the x, y and z-axis. Sequentially, the program will run and measure the length and width of the component, which is done by just touching the points of the component with the machine’s edge and head of the pointer needle. Figure 16: CMM measuring tool c. Following the guide program, we measured all the pockets and holes of the component; d. We used the digital micrometer to get the dimensions of the spherical section since the machine was not able to measure the sphere holder. e. Having completed the measurements using the program we generated an excel sheet report from the program options with detailed measurements of the component (see Table 2 below). CMM-Manager Report Part Name Part To Measure Date Thursday, February 19, 2015 Time 1:11 PM Unit MM Left_Face X -0.007 A/X 89°59'39." L 68.938     Y 8.159 A/Y 0°0'21."         Z -0.003 A/Z 90°0'0." F 0.000     Rear_Face X 9.764 A/X 0°0'27." L 113.944     Y 89.231 A/Y 90°0'27."         Z 0.005 A/Z 90°0'0." F 0.003     Right_Face X 139.154 A/X 90°0'38." L 37.843     Y 79.478 A/Y 0°0'38."         Z 0.012 A/Z 90°0'0" F 0.006     ARC_Front_Right X 106.225     R 33.012     Y 32.961     A 59°20'32"     Z 0.005     F 0.002     Front_Face X 98.988 A/X 0°0'1" L 84.432     Y -0.004 A/Y 89°59'59"         Z 0.002 A/Z 90°0'0" F 0.001     Slot_X_Y_Midpoint_L-Length_W-Width X 27.705 A/X 36°2'3" L 52.438     Y 23.920 A/Y 126°2'3" W 15.989     Z 0.000 A/Z 90°0'3" F 0.037     Depth_Of_Slot_Z X 0.000             Y 0.000             Z -13.972             Pocket_X_Y-Midpoint_L-Length_W-Width X 60.781 A/X 0°2'30" L 26.468     Y 45.387 A/Y 89°57'30" W 31.803     Z 0.004 A/Z 89°59'50" F 0.020     Depth_Of_Pocket_Z X 0.000             Y 0.000             Z -15.953             Circle_Left_Rear X 24.283     R 9.950     Y 66.586     D 19.900     Z 0.004     F 0.011     Depth_Of_Circle_Rear_Z X 0.000             Y 0.000             Z -17.859             Circle_Right_Front X 106.192     R 12.455     Y 32.154     D 24.910     Z 0.005     F 0.006     Depth_Of_Circle_Right_Front_Z X 0.000             Y 0.000             Z -9.964             Bolt_hole_1 X 104.368     R 3.056     Y 53.050     D 6.111     Z 0.007     F 0.065     Bolt_hole_2 X 123.345     R 3.010     Y 44.127     D 6.019     Z 0.007     F 0.007     Bolt_hole_3 X 125.147     R 3.011     Y 23.270     D 6.022     Z 0.005     F 0.012     Bolt_hole_4 X 108.007     R 3.002     Y 11.285     D 6.004     Z 0.003     F 0.001     Bolt_hole_5 X 88.996     R 3.008     Y 20.146     D 6.017     Z 0.003     F 0.006     Bolt_hole_6 X 87.197     R 3.034     Y 41.004     D 6.068     Z 0.005     F 0.013     Depth_Of_Bolt_hole_Z X 0.000             Y 0.000             Z -21.389             Circle_Right_Rear X 119.450     R 3.001     Y 74.691     D 6.002     Z 0.000     F 0.013     Depth_Of_Circle_Right_Rear X 119.320             Y 74.903             Z -21.709             Thickness_Touch_On_Granite_Table X 0.000             Y 0.000             Z -38.915             Table 2: CMM data report f. Lastly, we exported the data to excel sheet and used the necessary data to prepare a detailed component in SolidWorks CAD program (see fig below). Figure 177: CMM SolidWorks component g. Using BS8888 third angle projection in SolidWorks CAD we made a fully dimensioned component (see figure 8 below). Figure 188: Fully dimensioned component from CMM measurements Fundamentally, using CMM in measuring the component dimensions it will capture minor details since the system is automated to measure the component dimensions. The measurements obtained using CMM for the component dimensions are accurate since there are no human errors associated with the measurements because this is computerized dimension measuring system. Moreover, CMM provides consistent data which when used in SolidWorks CAD program no data calibration or fitting alterations are required to fit the desired component features. Therefore, components produced using this method are more precise, and they are similar in both size and shape. Conclusion When using any measuring device such like a digital micrometre or Vanier calliper it is important to remember to set the scale to zero (Curtis, 2013, 32). This helps in acquiring accurate data that is almost equal or same as the actual measurements. Moreover, same measurements can be compared using drawings made from SolidWorks CAD program, which produces an exact figure with the actual measurements without errors. Therefore, it would be easy to get data that are more consistent when close observation is made on the measuring tool. References Barbato, G., Germak, A., and Genta, G., 2013, Measurements for Decision Making. Measurements and Basic Statistics. Italy: Società Editrice Esculapio. Morris, A.S., 2001, Measurement and Instrumentation Principles. Oxford: Butterworth- Heinemann. Curtis, M., 2013, Handbook of Dimensional Measurement. 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For example, range in column A for diameter (X-axis) is 0.032 and that in column C is 0.024 this means that the recorded data is ± that range. In this case data in column C had a large discrepancy and hence a larger amount of error than the other columns. Measurements using a Digital Vanier calipers In this section, we measure a vee block using Vanier callipers. Figure 7: an assembly of a Vee block First, to measure the vee block alone, we separate the model and dismantle the component to get individual components.

Figure 8: Separated components of a Vee block Secondly, we utilized a Vanier calliper to evaluate the component measurements Figure 9: Digital Vanier Calipers When measuring internal and external sections of any given component and the data required must be very accurate, we use a digital Vanier callipers to get such measurements. However, it is necessary to make sure that the Vanier scale is set to zero prior to starting the measurements. The digital callipers has a display screen where the resulting measurements are displayed.

External features of any given component are measured using the lower jaw of the Vanier calliper while the upper jaw is measures the internal dimensions of the part. In case there is a need to adjust the calliper, the roller on the lower side is used for adjustments. Thirdly, we drew sketches showing the required measurements for the vee block design as shown in figure 10. Figure 10: Vee block labeled sketches However, we face some challenges when determining the curve angle from the U-shape, but we used a compass to draw the angle and determine the radius.

Figure 11: Determining the radius of the curves On completing the sketches, we used CAD SolidWorks program the create the final drawing, which indicated spare parts of the vee block then we assembled the parts in one drawing. Then we dimensioned the design using third angle projection BS888 as shown in figure 12. Figure 12: solid works drawing with the assembled drawing We used A4 paper and 1:2 scale for the CAD drawing of the component as shown in the above figure. Figure 13: U-shaped component The U-shape was dimensioned using SolidWorks CAD program; then we drew the locking pin in third angle projection using SolidWorks CAD program (see figure 13).

Figure 14: Locking pin component Coordinate measuring machine Measurement using Coordinate Measuring Machine (CMM) In this experiment, we used Kemco Kadet Coordinate Measuring Machine to measure the dimension of the experimental component. The CMM device is shown in figure 15 below and uses a program installed in a computer. Figure 15: Coordinate Measuring Machine (CMM) Measurement procedure: a. Depending on the points to be measured, we procedurally place the component on the machine table and then run the program. b. We allow the machine to touch the component edges to identify the x, y and z-axis.

Sequentially, the program will run and measure the length and width of the component, which is done by just touching the points of the component with the machine’s edge and head of the pointer needle. Figure 16: CMM measuring tool c. Following the guide program, we measured all the pockets and holes of the component; d. We used the digital micrometer to get the dimensions of the spherical section since the machine was not able to measure the sphere holder. e. Having completed the measurements using the program we generated an excel sheet report from the program options with detailed measurements of the component (see Table 2 below).

CMM-Manager Report Part Name Part To Measure Date Thursday, February 19, 2015 Time 1:11 PM Unit MM Left_Face X -0.007 A/X 89°59'39." L 68.938     Y 8.159 A/Y 0°0'21."         Z -0.003 A/Z 90°0'0." F 0.000     Rear_Face X 9.764 A/X 0°0'27." L 113.944     Y 89.231 A/Y 90°0'27."         Z 0.005 A/Z 90°0'0." F 0.003     Right_Face X 139.154 A/X 90°0'38." L 37.843     Y 79.478 A/Y 0°0'38."         Z 0.012 A/Z 90°0'0" F 0.

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