Specifying the Design Constraint Equations

Next, you specify the design constraint equations in terms of the global variables.

  1. In the Equations, Global Variables, and Dimensions dialog box, in the Equation View , under Equations, click the Add equation cell.
  2. In the FeatureManager design tree, expand Boss-Extrude1, and click Sketch1.
    The sketch dimension for the head diameter appears.

  3. Click the pin head diameter dimension.
    "D1@Sketch1" appears in the Equations, Global Variables, and Dimensions dialog box.
  4. Place the cursor in the Value / Equation cell and click Global Variables > Pin Shaft Diameter.
    "Pin Shaft Diameter" appears in quotes.
  5. After "Pin Shaft Diameter", type + .375 and press Tab.
    The resulting equation is "D1@Sketch1"="Pin Shaft Diameter" + .375. This equation specifies the first design constraint, that the pin head diameter is a function of the pin shaft diameter.
    If you do not specify units, the units for numerical entries are interpreted in the units of the dimension. In this equation, .375 is calculated in inches, the units for D1@Sketch1.
    The equation value .84379in appears in the Evaluates to column.
  6. In the Comments column, enter The pin head diameter is .375 inches bigger than the pin shaft diameter. and press Tab.
    A blank row of the Equations section appears.
  7. Select the global variables to enter the other design objective equations as follows:
    Equation Value / Equation Evaluates To Comments
    "D1@Boss-Extrude1" "Pin Shaft Diameter"/1.5 .31253in The pin thickness is proportional to the pin shaft diameter.
    "D1@Boss-Extrude2" "Base Length" 2in The pin shaft length is the same as the length of the base boss extrude.
    "D1@Sketch4" "Pin Shaft Diameter" + .0005 .46929in The diameter of the base boss extrude requires clearance.
    If you make an error while entering the name of a global variables on the right side of an equal sign, the text appears in red, indicating that the software cannot resolve the name of the global variable.
    Since Automatically rebuild is selected by default, the model is updated to satisfy the design requirements. Select Automatically rebuild if it is cleared.