Constraint-driven design
One robust model can represent a whole family of parts. Here you will drive a model from global variables so a single change reshapes the entire design.
Before you start
- Solid grasp of sketching and constraints
- A part with related dimensions
- 1
Identify the driving dimensions
Decide which dimensions define the family — bolt spacing, plate thickness, overall length — and which are derived from them.
- 2
Create global variables
Define named variables for the driving dimensions so they live in one place instead of being scattered across sketches.
- 3
Link dimensions with expressions
Set derived dimensions as expressions of the variables — for example, hole_offset = length / 2 — so relationships hold automatically.
Tip: Expressions capture design intent. When length changes, every dependent feature follows without manual edits.
- 4
Test the extremes
Push the variables to the smallest and largest members of the family and confirm the model rebuilds cleanly at both ends.
- 5
Generate the variants
Switch variable sets to produce each size in the family from the same master model, ready to export or manufacture.
What you built
A single parametric master model that generates an entire family of parts from a handful of variables.
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