Lab Assignment #3 ME170 Instructor: Date Due: Part I. Complete Exercise 4 (pg of the class text) Part II. Model a Styrofoam Cup

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1 Lab Assignment #3 Instructor: Mike Philpott ( Date Due: Sunday evening, September 28th, 2014 (11pm upload deadline) ME170 In this assignment, you will learn basic part modeling. First, you will model some parts from the textbook (Exercise 4). You will then create a Styrofoam cup model from the actual physical object. (You will be given a cup in class.) Be sure to bring a ruler or calipers, preferably with metric units, to avoid conversion errors. Part I. Complete Exercise 4 (pg of the class text) Before Beginning - Ensure that your working directory is set to your "ME170" folder on the desktop. - Remember to add your NetID to all new part files. The book will ask you to create a part named ' ' for example. Be sure to add your NetID to the part file name: "<netid>_ ". - Use the "170startpart.prt" to create all new part files. - Reorient your sketches using the "Sketch View" button. - Ensure that the sketch orientation in Creo's sketcher matches the book's sketch orientation. Use "Sketch Setup" to adjust the orientation. Instructions for altering the sketch orientation can be found in Lab 2. - Save often throughout the exercise. - Recall that you can set the "orientation" configuration option to "isometric" so that your "Standard Orientation" matches the book's. Instructions for this change can be found in Lab 2. Task 11 - Carefully note the dimensions on pg 118. Note that on one side the 3.80 and 4.00 dimensions reference the existing rectangle, not the new sketch. Task 12 - Ensure that all dimensions AND constraints are strong before confirming the sketch. Part II. Model a Styrofoam Cup There are four basic steps to create cup the model. This process is detailed in the laboratory instructions. i. Create the solid shape of the cup by revolving a solid protrusion. ii. Remove the inside of the cup using a revolved cut. iii. iv. Remove the bottom of the cup using and extruded cut. Complete your cup by adding your initials to the bottom of the cup using extruded text. Page 1 of 6

2 0) Open Creo Parametric. a. Open Creo Parametric 3.0 from the Start Menu. b. Set the working directory to your "ME170" folder on the desktop. c. Create a new part file named "<netid>_revolvecup". Remember to use your "170startpart" file as a template. d. Display your datum, axis, and point tags by pressing the appropriate three buttons in the "Show" section of the "View" ribbon. 1) Use the revolve tool to create the outer shape of the cup. a. Click the "Revolve" tool under the "Model" ribbon. b. Click "Placement" "Define". Select the Front datum plane as the sketch plane and click "Sketch". c. Click "Sketch View" to properly orient the sketch. Recall that you can click "Sketch View" at any time while working in the sketcher to realign a misaligned sketch. d. Sketch a vertical geometry centerline passing through the origin to serve as the axis of revolution. e. Sketch the outer shape of the cup. Do not adjust the dimension values just yet. f. Apply any logical constraints (eg. vertical 'V', horizontal 'H', parallel '//', coincident, etc.). Use your engineering judgment. g. Using the "Normal" tool, apply the dimensioning scheme shown below (image on next page). Begin with top diameter (d1), followed by the bottom diameter (d2), and finally the height (L1). Do not change Creo's automatic dimension values. In order to create a diameter dimension: i) Select the "Normal" dimensioning tool. ii) Left click the line or point, which you would like to dimension. iii) Left click the centerline. iv) Left click the same line or point selected in step '1.f.ii'. v) Click the middle mouse button to place the dimension. Page 2 of 6

3 h. Apply any additional dimensions or constraints as needed. Ensure that all dimensions are strong, dark blue, dimensions. i. Measure your cup to determine dimensional values for the dimensions shown in sketcher. Recall your length units, as set by the 170startpart, are millimeters. Dimensions that can be measured directly, such as the outer diameter of the cup, should be measured to within the nearest ½ millimeter. Small dimensions, fillets, rounds, etc. should be dimensioned to 'look right'. Do not change the dimension values in Creo just yet. j. Select your entire sketch and all of your dimensions by left clicking and dragging a box across the screen. k. Click the "Modify" tool. Uncheck "Regenerate", and enter the dimension values that you determined in step '1.h'. Click "OK" to confirm the new dimensions. l. Ensure that the sketch of your cup is a "closed" sketch. If your sketch is not closed, you will not be able to revolve a solid feature. m. Click the green "OK" checkmark in the upper right-hand corner of the screen to confirm the sketch. Page 3 of 6

4 n. Click the green checkmark in the "Revolve" ribbon to confirm the revolution. 2) Create the inner surface of the cup using a revolved cut. a. Click the "Revolve" tool. Click the "Remove material" icon. b. Click "Placement" "Define". Select the Front datum plane as the sketch plane and click "Sketch". c. Click "Sketch View" to properly orient the sketch. d. Sketch a vertical geometry centerline passing through the origin to serve as the axis of revolution. e. Select additional references for the sketch. i) Click the "References" button in the upper left corner of the "Sketch" ribbon. ii) Left click the top surface of the cup and the longest diagonal edge to specify the surfaces as sketch references. iii) Click "Close" to exit the sketch references dialog box. f. Sketch the inside geometry of the cup as shown below. Define logical constraints. Apply an appropriate dimensioning scheme. Measure the cup and correspondingly edit the dimension values. Ensure that there are no weak dimensions in the sketch. Page 4 of 6

5 g. Click the green "OK" checkmark in the upper right-hand corner of the screen to confirm the sketch. h. Click the green checkmark in the "Revolve" ribbon to confirm the revolved cut. 3) Create the bottom recess feature with an extruded cut. a. Click the "Extrude" icon in the "Model" ribbon. Click the "Remove material" icon, as in step '2.a'. b. Click "Placement" "Define". Select the bottom surface of the cup as the sketch plane. (You may have to rotate the model in the model window in order to be able to view and select the bottom surface.) Click "Sketch". c. Click "Sketch View" to properly orient the sketch. d. Sketch a circle for the extruded cut. e. Measure the bottom recessed feature on the physical cup and edit the value of the diameter dimension in Creo. f. Click the green "OK" checkmark in the upper right-hand corner of the screen to confirm the sketch. g. Define an appropriate extrusion depth. h. Click the green checkmark in the "Extrude" ribbon to confirm the extruded cut. 4) Add extruded text to the bottom of the cup. a. Add your initials to the bottom of the cup using extruded text. Follow the instructions in Appendix A, Exercise 29 (pg A-12), of your textbook to create extruded text. Change the extrusion surface, text string, text dimensions, font, aspect ratio, extrusion depth, etc. to neatly place your initials on the bottom of your cup. Part III Homework Submission Requirements 1) Create a folder called "Lab3" within your "Submissions" folder (which should be located in your "ME170" folder on your desktop). 2) Copy and paste the following files to the "Lab3" folder. Do not cut-paste or remove the files from your ME170 folder, create a copy of them in the new directory. Be sure to include the latest version of each part. (Ensure that '#' is the highest numbered file in your ME170 directory.) See Lab 1 for instructions on how to display the version number if it is hidden. netid_ prt.# (from Part I) netid_ prt.# (from Part I) netid_ prt.# (from Part I) netid_ prt.# (from Part I) netid_revolvecup.prt.# (from Part II) Page 5 of 6

6 You are required to complete the additional parts in Exercise 4; however, you do not need to submit them at this time. The parts created in this exercise will be used in future exercises. 3) Once you have double-checked that all the correct files are in your "Lab3" folder, navigate back to the "Submissions" folder. Right-click the "Lab3" directory. In the menu that appears, select "7-Zip" "Add to "Lab3.zip"". 4) Rename your new zip file to include your NetID: "<netid>_lab3.zip". 5) Submit your "<netid>_lab3.zip" file via the my.mechse website. See Lab 1 for instructions on how to submit files through this website. Page 6 of 6