Measurements Using a Digital Vanier Calipers and Coordinate Measuring Machine - Lab Report Example

Measurements Name: Registration no: University: Course: Lecturer: Introduction Measuring devices have different features that allow them to be used in different situations and measuring of diverse components sizes. Therefore, for every shape in a component a measuring tool is used to determine the dimensions of the component. However, some measuring tools will have human errors since they involve human observations. Such measuring devices require averaging to get data that is almost to the actual measurements of the component. 1. Measurement using a digital micrometer There are three columns A, B and C of aluminum test specimens and each column has five specimens. In this experiment, we are measuring the length and diameter of each specimen starting from the letter then measuring each specimen number in their column. In order to provide accurate measurements of the specimen, a length digital micrometer with a minimum of 25mm and a maximum of 50mm as the default measurements is the ideal tool to use (see figure). Figure 1: 25 to 50 mm micrometer Prior to measuring the dimensions using the micrometer, it is important to zero the micrometer so that is start measuring from 25mm which may use the specimen below. After fitting the specimen on the micrometer and tie the scroll until it reaches the 25mm the we press (set) on the micrometer. After setting the micrometer, we then started t fit the specimen and measure the length noting the results in a column table for each specimen. Using a different micrometer with 0 to 25 mm measurement (fig below), we repeated the same procedure for the specimen Figure 2: 0 to 25 mm micrometer Using the above micrometer and repeating the same procedure for length measurement, we observed and recorded the results for the diameters in a table for each specimen. All the data for the lengths and diameters for the specimens we recorded them in table below. Column A Column B Column C   Length Diameter Length Diameter Length Diameter 1 27.5 5.058 26.293 5.036 27.413 5.024 2 27.536 5.055 27.528 5.035 25.66 5.036 3 27.513 5.031 27.483 5.022 27.42 5.032 4 27.424 5.036 27.516 5.036 27.504 5.038 5 27.417 5.039 27.526 5.47 27.421 5.027               Mean 27.478 5.0438 27.2692 5.1198 27.0836 5.0314 Range 0.119 0.027 1.235 0.448 1.844 0.014 Using the data we gathered, we calculated for range and means for all tests. We calculated mean by adding all the lengths in every column and dividing by 5 for each column. The same procedure for calculating mean was repeated for the diameters. To calculate range for lengths and diameters, we subtracted the max length value in each column and subtract the min length from each column to get the range. The same was repeated to calculate range for the diameters. All experimental measurements are prone to uncertainties. Therefore, there is a need to calculate the mean values to determine the most accurate measured value to use from measurements made. Additionally, the range value is the difference between the max value and the min value, which give the amount of error in the measurement. When the range is determined, it gives an approximate discrepancy between the measured value and the accurate measurement. In this experiment, we measure the mean values for the lengths and the diameters to determine the nearest measured value to the accurate values. While the range gave the amount, error in each data presented from the measurements made. When making measurements using micrometers, the data must show consistency and repeatability meaning that, the data is most accurate and close to the true values. For instance, from the recorded data, the range for column A diameter is 0.027 and column D diameter range is 0.14, which means the data is ± that range. This means that the data for the two columns is most accurate compared to other columns. 2. Measurements using a digital Vanier calipers The task here is to measure a Veeblock shown below Figure 3: Veeblock Assembly First, we had to separate the model to get each component alone to measure the Veeblock (see fig below). Figure 4: Separated components of a Veeblock Secondly, we used a Vanier caliper to measure the component Figure 5: Digital Vanier Calipers A digital Vanier calipers is used in measuring the most accurate data for components that have internal and external sections that are complex to measure using normal measuring instruments. To get accurate readings the digital Vanier calipers is set to zero. The digital calipers have a screen that displays the measured value of the component. To measure readings for all external features of the components, the lower jaw is used and the upper jaw is used to measure the internal features of the component. The roller on the lower side is used when adjusting the calipers for accuracy. Thirdly, we sketched and labeled measurements for each component as indicated in the figure below. Figure 6: Vee block labeled sketches However, we had difficulties measuring the angle of the curve from the U shaped locker, which we figured it our by drawing it on a paper using compass to determine the radius. Figure 7: determining the radius of the curves Having completed the sketching of the component parts of the Vee block, we used solid works CAD program to create separate drawings showing all the parts separately. After we had drawn all the parts, we assembled them in a fully dimensioned design. The design is a third angle projection BS 8888, which is shown in the figure below. Figure 8: solid works drawing The above figure is an assembly of the Veeblock components in solid works CAD program with the components fully dimensioned and assembled an A4 paper with a scale of 1:2. For the U shaped component the dimensioning and the drawing was done in solid works CAD programme and the design was done shown in the figure below. Figure 9: U shaped component After drawing and dimensioning the U shaped component, the locking pin was drawn in solid works CAD program in third angle projection as indicated in the figure below. Figure 10: Locking pin component Having completed the locking pin and the U shaped components, the Vee block component was drawn as per the measured dimensions using the solid works CAD program and labeled accordingly (see fig below). Figure 11: Vee Block component When using the digital Vanier Calipers, the measurements are set to zero prior to starting the measuring process. This is to ensure that most accurate data is measured and that it would tally with the actual measurements of the component. Having observed the accuracy in the measurements, the recorded readings are mirrored in the solid works CAD drawing which has an exact figure of the vee block components when the measurements made using the calipers are used. This is an indication for proper consistency in the measuring and data recording made from the calipers, thus the calipers has consistency in measurements. 3. Measurement using coordinate Measuring Machine (CMM) Measurements here were made using a KemcoKadet Coordinate Measuring Machine (CMM). This is a program installed in the computers that we used do the measurements. The CMM device is shown below. Figure 12: coordinate Measuring Machine (CMM) To the measure the component using the machine the procedures to follow are as follows: 1st, we place the component of the machine table and start running the program on the computer, which is set procedurally depending on the points to be measured. 2nd, to allow the machine to identify the X, Y and Z-axis, touch the edges. Then the programe will sequentially run measuring the length and width the component by simply touching the edge of the machine and the pointer needle head to the specified number of points of the component. Figure 13: CMM Measuring tool 3rd, measure all the holes and the pockets of on the component by following the guide on the program 4th, since the machine will not measure the sphere holder, then we used digital micrometer to get the required dimensions. 5th from the program options, the program will generate an excel sheet with the measurements from the component, this is as tabulated below. CMM-Manager Report Part Name Part To Measure Date Wednesday, February 19, 2014 Unit MM Left_Face X -0.011 A/X 90°1'0"         Rear_Face Y 89.224 A/Y 90°1'22"         Right_Face X 139.093 A/X 89°59'27"         ARC_Front_Right X 106.330     R 32.851     Y 32.820             Front_Face Y -0.071 A/Y 89°59'19"         Slot_X_Y_Midpoint_L-Length_W-Width X 27.739 A/X 35°57'50" L 52.382     Y 23.890 A/Y 125°57'50" W 15.885     Depth_Of_Slot_Z Z 0.011             Pocket_X_Y-Midpoint_L-Length_W-Width X 60.869 A/X 90°58'43" L 31.389     Y 45.219 A/Y 0°58'43" W 26.272     Depth_Of_Pocket_Z Z -15.959             Circle_Left_Rear X 24.245     R 9.912     Y 66.531             Depth_Of_Circle_Rear_Z Z -17.864             Circle_Right_Front X 106.165     R 12.427     Y 32.035             Depth_Of_Circle_Right_Front_Z Z -9.901             Bolt_hole_1 X 104.356     R 3.011     Y 52.966             Bolt_hole_2 X 123.302     R 2.980     Y 44.053             Bolt_hole_3 X 125.128     R 2.967     Y 23.245             Bolt_hole_4 X 107.990     R 2.982     Y 11.217             Bolt_hole_5 X 89.002     R 2.975     Y 20.073             Bolt_hole_6 X 87.182     R 3.002     Y 40.960             Depth_Of_Bolt_hole_Z Z -21.287             SPHERE X 119.444     R 9.017     Y 74.634             Z 16.038             Thickness_Touch_On_Granite_Table Z -38.915             6th, export the excel sheet data and then use the important data to prepare a Solid works CAD component (see fig below). Figure 14: CMM solidworks component 7th using third angle projection using the BS8888, a fully dimensioned component is drawn with all the dimensions. The complete drawing is produced in solid works using the measurements made with CMM, which is as indicated in fig below. Figure 15: Fully dimensioned component from CMM measurements Essentially, CMM is capable of acquiring minor details in the readings since it is automated to produce the measurements. When using the CMM to measure the component parts, the obtained measurements are accurate since this is computer generated and has no human errors like other modes of measuring components. On the other hand the CMM data is consistent in such a way that when used in the solid works CAD program it does not need calibration and alterations to fit the desired features. Additionally, all the data from the CMM shows consistency and repeats all same data for any similar component part. 4. Other liner measurement methods a. Measuring the taper head of a component Figure 16: measuring taper This is done simply by using various floating positions and inserting the work piece to determine its dimensions and size (see fig above). b. Measuring the centricity of a component Figure 17: centricity measurement This is is measured via determining the wall thickness of the component as indicated in the fig above References Krishnan, G.V. Thomas S., 2012, Harnessing AutoCAD: 2013 and Beyond, New York, Cengage Learning, 89. Planchard, M.P., 2012, Engineering Design with Solid Works 2012, California, SDC Publications, 23. Walker, H. F., Donald, W. B., & Ahmad, K. E., 2013, The Certified Quality Technician Handbook, Second Edition, Michigan, ASQ Quality Press, 76. Read More