While Design models or creating assembly we have to give dimensions and some dimensional constraints to the Assembly model. When we draw the basic Sketch to start the designing we try to make the sketch fully defined. We you give dimensions, constraints, and relation to the sketch becomes Black means it is fully constrained. Creating a fully defined sketch is very important, if in the future we have to make some changes we can do that without getting any errors.
Sometimes while designing the models some parameters have some link or relations. For example, the height of a cylinder is 100mm and its outer diameter is 50 mm, and this dimension will remain in the same ratio. If we increase the height to 120mm, the diameter will become 60mm. So we can create a link or relation between these two dimensions.
There are two ways by which we can link the dimensions.
- Link Value
- Creating Global variables.
Link Value
To explain how to use this feature we will take an example. In this example, we will take one cuboid and the boundary condition is that the front face dimension has to be the same. The height and width of the cuboid need to be of the same dimension. So to do this we will draw one sketch and give the dimensions to it. And then we will link those dimensions.
To use the link values command right click on the Width dimension. From the Right menu options go to Link values. This will prompt a dialog box named Shared values. In this give the name of the value and click on OK. In the dimension now you will see the name and an Infinity sign in front of the dimensions.
Now we have to apply this link to the height. Right Click on the Height dimension and click on Link values from the right menu. In the prompt dialog box, you have to select the last link value which we have created. By clicking on the dropdown button, we can select the link value. Then click on OK. Now both dimensions are linked together. If we change the value in Width, that value will automatically update in the height dimensions.
To change the value double click on the dimension and insert the value and click on OK.
Creating Global Variable
Creating a Global Variable is simple. In this, we can create the global variables at any time and then apply them when needed. We can create equations, and formulas, use universal variables(pie), etc. with the global variable.
To create the Global Variable go to Tools > Equations.
Now you can add the global variable by giving the name, value, and its SI unit. After creating the Global variable click on OK.
Go to sketch use the smart dimension tool and measure the sketch where you want to use this global variable. In the prompt dialog box type ” = ” Sign you will get three options. Go to Global variable and select the variable which you have created and want to use. Then click on OK. You will see the Symbol in the before dimension value that symbol is of Global Equation.
You can make changes to the equations from the features tree. Right Click on the Variable under Equations and select Manage Variables. This way we can make changes to this global variable.
