What's the difference between STL and STEP files?

STL and STEP are both 3D file formats, but serve different purposes.

STL Files (Standard Triangle Language)

What it is:

  • Mesh-based format (triangles)
  • Standard for 3D printing
  • Contains only geometry, no history

Use STL when:
✅ Sending to a 3D printer
✅ Final design, ready to manufacture
✅ Uploading to print services

Limitations:

  • Cannot easily edit dimensions
  • No parametric history
  • Hard to modify after creation

STEP Files (Standard for Exchange of Product Data)

What it is:

  • CAD exchange format
  • Preserves solid geometry
  • Industry standard for manufacturing

Use STEP when:
✅ Importing into Fusion 360, SolidWorks, FreeCAD
✅ Making modifications to the design
✅ Need precise dimensions
✅ CNC machining

Advantages:

  • Editable in CAD software
  • Accurate curves (not triangulated)
  • Includes face and edge data

Which Does Modo Provide?

Modo generates both:

  • STL: Ready for immediate 3D printing
  • STEP: For users who want to modify designs

Quick Comparison:

| Feature | STL | STEP | |---------|-----|------| | 3D Print Ready | ✅ Yes | ⚠️ Needs conversion | | Editable | ❌ No | ✅ Yes | | File Size | Smaller | Larger | | Accuracy | Approximated | Exact | | Best For | Printing | Modifying |

Workflow:

  1. Just printing? → Use STL directly
  2. Want to modify? → Import STEP into Fusion 360 or FreeCAD
  3. After modifications → Export new STL for printing