The Siemens PLM CAD software NX is commonly used for designing mechanical systems, and in complex systems such as the emerging area of wind power, the ability to have a model controlled by design parameters is a certain advantage. Formula driven expressions based on the amount of available wind in an area can drive the amount of effective surface area of a lift type blade, and therefore drive the shape and size of the system. NX allows the user to insert expressions into the model to resize the shape of the model based on these formulas. Introducing future design engineers to this methodology using scaffolding techniques can encourage them to optimize the usability of a CAD model. This paper introduces the methodology of designing Darrieus style blades for vertical and horizontal residential wind turbines that is used to illustrate to students the capability of creating a formula driven solid model. This methodology can be used to create any mechanical system that may need updates depending on user needs driven by a formula, which in this case is the amount of power output in certain wind conditions (Irwin, 2011). The scaffolding instructional technique has resulted in several successful student projects that have implemented expression driven parametric assembly models.