From Mouse Clicks to Code: Parametric Python Automation
Yesterday we built the wrench manually. Today, we throw away the mouse.
Welcome to the WrenchDesign class—the core of our automation pipeline. This Python script generates a complete parametric wrench in seconds. No GUI. No mouse. Just code.
WHAT WE'RE BUILDING:
A WrenchDesign class that accepts design parameters and outputs a watertight STL file ready for CFD. The parameters we control:
Handle Length: 40-500 mm (trade-off: longer = easier grip, more drag)
Handle Width: 5-50 mm (affects aerodynamics)
Handle Thickness: 2-30 mm (structural constraint)
Head Size: 10-80 mm (opening width constraint)
Opening Width: 5-30 mm (must fit the bolt!)
Neck Radius: 0-15 mm (blend between handle and head)
Aero Factor: 0-1.0 (streamlining intensity)
THE CLASS STRUCTURE:
class WrenchDesign:
def __init__(self, params=None):
Initialize with design parameters
def validate_params(self):
Check bounds on all variables
def build_wrench(self):
Orchestrate geometry creation
def export_stl(self, filepath):
Output for CFD (scaled to SI)
UNDER THE HOOD:
Part.makeBox: Create the handle as a rectangular solid
Part.makeCylinder: Create the head
Boolean Operations: Cut the opening, fuse components
Part.makeFillet: Round edges for aerodynamics
tessellate() + Mesh.export(): Generate and save STL
KEY INSIGHT:
10 design parameters × 5000+ combinations = infinite design space.
But we're not exploring randomly. Tomorrow we'll set up the CFD pipeline. Then Dakota will intelligently search this space and find the optimal design.
CODE SNIPPET:
```python
from wrench_parametric import WrenchDesign
params = {
'handle_length': 200,
'handle_width': 20,
'handle_thickness': 12,
'head_size': 30,
'opening_width': 12,
'aero_factor': 0.5
}
design = WrenchDesign(params)
design.build_wrench()
design.export_stl('wrench.stl')
```
PERFORMANCE:
Manual FreeCAD: ~10 minutes per design
Python Script: 0.1 seconds per design
Speedup: 6000x
That 0.1 seconds becomes our greatest advantage we can now evaluate thousands of designs in an afternoon.
Ever used Python to automate CAD? What was your experience?
#Python #FreeCAD #CAD #Automation #Engineering #ParametricDesign #Day2