Recitation Activities Lab Activities Dimensional inspection part features for dimensional conformance is a key aspect of assuring that complex geometry components meet the required dimensional specifications. For a complex part such

as an automotive engine block, it is not uncommon for more than 500 features and dimensional characteristics to be inspected to fully insure dimensional conformance. In lab selected features on sand cast, investment cast, and forged parts will be measured to determine manufacturing dimensional capability and process capability. In addition, features will be measured multiple times by multiple "inspectors' to also assess measurement system repeatability and reproducibility (Gage R&R). *****These are key concepts*****Master them***** Measure the part feature size (in.) for the features indicated using hand-held digital calipers. (Use the measurement technique of your choice, but use the same measurement technique each time you measure a given feature.) Part 1 2 3 4 5 6 7 - discussion of dimensional variability, process capability, gage R&R -discussion of lab data collection and reporting 8 9 10 Comment on the ease or difficulty of measuring the feature Ave. Std. Dev. Ceramic Processing Module - IN-PERSON Lab Dimensional Conformity & Measurement System Analysis Dwg. Dimension SC-sand casting F-forging IC-investment casting F Middle- SC Middle Flange OD Operator 1 1.8125 1.8200 1.8226 1.8095 1.8225 1.8135 1-8195 1.8230 1.8185 1.8240 Boss Dia. (parallel to flash axis) IC Flange Width Operator 4 Operator 3 1.2680 0.3100 1.2665 0.3080 1.2 Cas L2635 1.2780 0. 3090 0.3070 0.3080 1.2760 0.3100 L2695 0.3080 1.2755 0.30 95 42670 0.3090 2755 0.3096 1.810 1.270 0.305 +/- 0.008 in +/-0.015 in +/- 0.005 in SC Middle Flange OD Operator 1 (repeat) 1.$165 1.8065 1.9110 1.8146 1.8190 1.8165 1.8170 1.8 140 1.8110 4.8165 1.810 +/-0.008 in SC Middle Flange OD Operator 2 1.8260 1.8205 1.8.275 1.8 110 1.8305 1.8 210 1.9 220 1.8 240 1.8 245 1.8 280 1.810 +/-0.008 in SC Middle Flange OD Operator 2 (repeat) 1.8215 1. $215 1.8275 68120 1.8330 1.8175 1.8195 1.8290 1.8195 1.8295 1.810 +/-0.008 in/nLab Report (2 pages text, single-spaced + data presentation and interpretation figures and tables) DIMENSIONAL CAPABILITY AND PROCESS CAPABILITY Calculate the average and standard deviation for each set of feature measurements. From these calculations, determine the process capability (Cp) and the process capability index (Cpk) for each set of measurements. Comment on the relative Cp and Cpk values for each process as well as the conformance of the part features to the dimensional specifications. Include figures that show the actual data with respect to the dimensional UCL and LCL If Cpk is less than 1.33 for a feature, determine the appropriate tolerance limits for which a Cpk of 1.33 is achieved (a reverse Cpk calculation). MEASUREMENT SYSTEM ANALYSIS (GAGE R&R) For the green sand flange outer diameter data, use the data collected multiple times by multiple operators to determine the repeatability and reproducibility of the calipers and to determine whether or not the gage R&R of the digital calipers is adequate (based on both customer tolerance and on process variability). Comment on the role of operator training measurement system improvements on Gage R&R. aby E(MS or n #replications, o #operators, p&#parts = ⇒0Par LIL = Measurement Error vs Uncertainty Repestability Soperater)=biy+p-n-p E(MS) Repeatablity 1% n-o 30% ⇒ operator n.p E(MSP)=biy +r.p.o Part E(MS par)-estability LL 10% 80% US