Using Variables and Formula-driven Dimensions in Autodesk InventorA Closed Profile with Constraints AddedDimensionsPlacing Parametric DimensionsGeometric RelationshipsFirst Sketch – Line CommandA Fully Constrained Profile using Geometric Constraints and Parametric DimensionsFormulas in Dimensions (1)PowerPoint PresentationVariable Names and Formulas (3)Formula Driven Dimensions (3)Example of using Formulas and Variables with a part from a Catalog Form1SheetCourse: Introduction to Engineering Graphics and Visualizationcopyright 2011, Georgia Institute of Technology1Using Variables and Formula-driven Dimensions in Autodesk Inventor•Parametric Dimensions•Geometric Relationships•Variables•Formulas2SheetCourse: Introduction to Engineering Graphics and Visualizationcopyright 2011, Georgia Institute of TechnologyA Closed Profile with Constraints AddedAdding geometric constraints reduces the number of dimensions that must be added to fully constrain a profile.1. Add as many geometric constraints while drawing the closed profile using the automatic geometric constraints.2. Delete any geometric constraints mistakenly placed during the drawing of the closed profile. F8 - Highlight - Delete3. Add additional geometric constraints as required. 4. Add all necessary dimensions to fully constrain the closed profile. Note: From a Designer’s point of view, the fewer the dimensions used and the more geometric constraints used the better.3SheetCourse: Introduction to Engineering Graphics and Visualizationcopyright 2011, Georgia Institute of TechnologyDimensions•Dimensions are used to label and control the size, location, and orientation of 2-D elements.•Dimensions or constraints should be placed even if the value was entered when the element was created. Until the geometry is constrained, it can change.4SheetCourse: Introduction to Engineering Graphics and Visualizationcopyright 2011, Georgia Institute of TechnologyPlacing Parametric DimensionsDimensioning Commands–General Dimension-used to apply all parametric dimensions–Auto Dimension – best if used to add geometric constraints only5SheetCourse: Introduction to Engineering Graphics and Visualizationcopyright 2011, Georgia Institute of TechnologyGeometric RelationshipsUsed with dimensions to control the size, shape, and position of the profile.6SheetCourse: Introduction to Engineering Graphics and Visualizationcopyright 2011, Georgia Institute of TechnologyFirst Sketch – Line Command7SheetCourse: Introduction to Engineering Graphics and Visualizationcopyright 2011, Georgia Institute of TechnologyA Fully Constrained Profile using Geometric Constraints and Parametric DimensionsNote: All geometric constraints in this case were automatically added while sketching.CoincidentTangentParallel/PerpendicularDimensions8SheetCourse: Introduction to Engineering Graphics and Visualizationcopyright 2011, Georgia Institute of TechnologyFormulas in Dimensions (1) 1. Place the Parametric Dimensions on the profile.2. Select “Parameters” from the Manage PanelUse one Dimension to drive other dimensions when there are size and location relationships in the part.9SheetCourse: Introduction to Engineering Graphics and Visualizationcopyright 2011, Georgia Institute of TechnologyFormulas in Dimensions (2) Make Dimension Expression visible to make it easier to drive other dimensions when there are size and location relationships in the part. With nothing selected in the sketch.Right click in the graphics window and select expression from the dimension display fly-out menufx: in front of a dimension means it is link to another dimension or driven by an equation.With dim display set to expression the name of the dim and the formula are displayed.The square in the is centered on the part by taking the overall width of the part, subtracting the width of the square, and dividing the result by 2. Since it’s referencing other dims as they update so does the formula.10SheetCourse: Introduction to Engineering Graphics and Visualizationcopyright 2011, Georgia Institute of TechnologyVariable Names and Formulas (3)1. Change the name of the d3 dimension (1in) to “Step”.2. Use this variable name to create a formula to drive the d2 (1.5”) dimension.11SheetCourse: Introduction to Engineering Graphics and Visualizationcopyright 2011, Georgia Institute of TechnologyFormula Driven Dimensions (3)Changing the value of the parametric dimension renamed “step” will automatically change the driven dimension value.Note: The dimension that is driven by another always has a fx: in front.12SheetCourse: Introduction to Engineering Graphics and Visualizationcopyright 2011, Georgia Institute of TechnologyExample of using Formulas and Variables with a part from a Catalog