Flexible Parametric Design: An Onshape Advantage

Parametric modeling is powerful, but as designs grow in complexity, so do the challenges. How do you build a model that can adapt to change without breaking? How do you structure your data so that your team can understand and build upon it? Designers and engineers have always struggled with these questions.

Onshape takes a fresh approach to age-old problems in CAD software.

The Multi-Part Part Studio: Your Foundation

One of the most powerful methods for establishing robust design intent is the multi-part Part Studio. By designing parts together that are functionally related, you create easy-to-manage inherent relationships.

This approach is supercharged by layout sketches (or "skeleton sketches"). A single, top-level sketch can define the critical dimensions and positions for dozens of parts.

As seen in the dump trailer example in the video below, a change to the layout sketch for the frame or axle assembly intelligently updates every associated component simultaneously. This top-down methodology is the bedrock of flexible design.

Configurations, Variables, and Expressions

Onshape handles configurations in a uniquely powerful way, eliminating the need for massive, error-prone spreadsheets. Instead of defining every single design permutation, you create independent inputs that work together.

A perfect example is the ANSI pipe flange, a simple part with thousands of potential variations based on size, pressure class, and style. This is achieved not with thousands of table rows, but with a few key tools:

• Variables and Expressions: A simple expression can determine a "class" based on a pressure rating input.
• Arrays: That "class" then pulls the correct values (diameter, thickness, bolt pattern) from a simple list or array.

This logic extends to feature parameters. This is "if-then" logic built directly into your features, creating a model that intelligently adapts itself.

Getting Deeper Into Design Intent and Organization

To capture the design intent, engineers must plan ahead:

• What needs to be flexible? Not all parts are created equal. Identify components that will be configured or are likely to change and invest your effort there.
• What is geometrically dependent? Understanding the relationships between parts helps you decide what to model together in a multi-part Part Studio.
• How will this be manufactured or assembled? Thinking about manufacturing early on informs your feature choices and structure, saving significant rework later.
• How do I communicate my intent? A design is only as good as it is understood. How can you organize your model so a teammate – or your future self – can grasp its logic instantly?

Answering these questions lays the groundwork for a robust model that doesn't just represent a shape, but captures the why behind it. Watch Greg Brown, VP of Product Management at Onshape, explain some data organization fundamentals.

Onshape offers an unprecedented level of flexibility in organizing design data, making it a powerful CAD tool. Try it yourself.