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Activity 8.2 Parametric Constraints Introduction Have you ever received an advertisement in the mail that looked like it was tailored specifically for you? How could the company afford to spend so much time and money entering your name and other personal information into the various locations of the advertisement? In order to create such advertisements, the company will store your personal information within a database. A computer will then plug specific pieces of your personal information into various locations on a generic document with links to the database. The same thing happens with email advertisements. This type of work takes a great deal of preplanning to pull off, but the efforts are worth it if a number of customers respond. Procedure 1. Study the image below and table on the next page. Complete the following tasks. a. Use the given information to fill in the missing parametric equations and missing numeric values for each parameter in the table below. Dimension d0 Description Overall Plate Depth d1 Overall Plate Width Geometric Relationship ‐‐ 5:3 ratio; overall plate width to overall plate depth Parametric Equation ‐‐ Value 3 in. d0*(5/3) 1.67 d2 Plate Thickness d3 Plate Taper Angle d4 d5 d6 d7 d8 d9 d10 d11 d12 d13 d14 Slot Width Slot Width Location Slot Depth Location Slot Radius Slot Extruded Height Slot Taper Angle Hole Width Location Hole Depth Location Hole Diameter Hole Extruded Height Small Hole Taper Angle 20 times smaller than the overall width perpendicular to the top and bottom plate surfaces ½ the overall plate depth 4/5 of the overall plate width 1/3 of the overall plate depth same as the plate thickness same as the plate thickness same as the plate taper angle ¼ of the overall plate width 2/3 of the overall plate depth twice the slot radius same as the slot height same as the slot taper angle d1/20 0.0835 ‐‐ 0° d0/2 d1*(4/5) d0*(1/3) d2 d2 d3 d1*(1/4) d0*(2/3) 2*d7 d8 d9 1.5 1.36 1 0.0835 0.0835 0° 0.42 2 0.167 0.0835 0° b. Use your parametric equations to create the object above in a 3D CAD solid modeling program per the instructions below. Be sure to use the same parameter names for each dimension as identified in the table in number 1 above. The only numeric values that you should enter are 3 inches for dimension d0, and 0° for dimension d3. All other parameters should be defined using a formula. When finished, save the file and identify its name and location in your student folder. NOTE: The hole (diameter d12) was created using the CIRCLE tool. Sketch a rectangle. Dimension the depth first (d0) and then the width (d1). Extrude the rectangle the appropriate distance (d2) using a formula. Note that a parameter will automatically be assigned for the taper angle (d3) of the extrusion. The default taper angle is zer0 degrees. Sketch and dimension the slot on the top surface of the plate using the parameter names shown and the appropriate formulas. Be sure that the semicircular ends of the slot are tangent to the straight edges of the slot. Extrude Cut the slot the appropriate distance (d8). Again, a parameter will automatically be assigned for the taper angle of the extrusion (d9). Sketch and dimension a circle on the top surface of the plate to represent the hole using the parameter names shown and appropriate formulas. Extrude Cut the hole the appropriate distance (d14). Again, a parameter will automatically be assigned for the taper angle (d13). Record the physical properties of the part below. Volume: 3.464 in^3 Surface Area: 33.250 in^2 Change the overall plate depth to 1.5 inches, that is d0 = 1.5 in. Be prepared to demonstrate the change to your teacher. Describe what happens to the plate and the features when you revised the dimension. The part is exactly the same the only difference is that it is smaller. Record the physical properties of the part after it is resized. Volume: 0.433 in^3 Surface Area: 8.313 in^2 Conclusion Questions 1. What is the difference between a numeric and a geometric constraint? A geometric constraint is not stuck at a certain numerical value. 2. What advantages are there to using parametric equations instead of numeric values? You can easily change the size of the whole part. 3. What disadvantages are there to using parametric equations for numeric values? It is more time consuming to set up. 4. Describe a situation in which using parametric equations to dimension an object would be helpful. When you make a part when you know you want to change the size later.