I have had a lot of clients (mostly in manufacturing) lately that are looking at constraints in AutoCAD as the answer to be able to control drawing geometry not only for accuracy, but to assist them in quick changes by editing existing content, or to create new similar content without having to worry about losing the original shape and intent of the design. In some cases I found that some of the designers have less than 15 minutes to change a shop drawing  to reflect the new sizes with the updated dimensions before they need to move on to the next client, and that this is a typical every day operation. They are also very adamant about using AutoCAD to accomplish this. So in light of these new requests, let’s start with a brief intro of by utilizing Parametric Constraints.

First of all, a Parametric Constraint is a tool that was first introduced to AutoCAD in release 2010, and allows you to control how the object geometry behaves between object to object to maintain the shape or intent of your design. With parametric drawing, you can add constraints to 2D geometry. Constraints are rules that determine the placement of objects with respect to each other, and their dimensions. Typically, constraints are used in the design phase of a project. Changes made to one object can adjust other objects. For example, if a line is constrained to be tangent to an arc, changing the location of the arc maintains the tangency automatically. These are called geometric constraints.

You can also constrain distances, diameters, and angles. These are called dimensional constraints.For example, say that a diameter of a circle that may represent a bolt hole in a part, but the diameter may have to change size later and if it does you may want all of the other bolt holes to change to the new size as well. So you could assign an equal constraint to all of them; and because the circles are constrained to be equal size, if you change the one, it would change the diameter of the rest. This also allows the capabilities to provide a way to try out ideas and make design changes efficiently, while maintaining specified relationships and distances.

Over the next few Blogs or so we will explore these different types of constraints to create Parametric drawings, and let me know if you have questions along the way so that I can include them in my blogs.