🔷 Corner Handling Modes

Three Approaches to Zigzag Blade Corners

📋 Overview

When zigzag blade segments meet at corners, different geometry treatments can be applied. The blade system supports three corner handling modes, each with different trade-offs.

Mode Name Complexity Recommended For
0 Overlap + Union Simple Prototyping, general use
1 Miter Cut Medium Production tooling
2 Radius Blend Medium Smooth material flow

🔷 The Three Modes

Overlap + Union

Mode 0 (Default)
Segments BEFORE union: Seg 1 extended Seg 2 extended ────────────╲ ╱──────────── ╲ ╱ X ← Overlap region ╱ ╲ After BOOLEAN UNITE: ──────────────╲ ╲ ╲──────────── Corner forms automatically!

Extend each segment past the bend point, then boolean unite. The overlapping region merges naturally.

Pros

  • Simplest to implement
  • Self-correcting (no gaps)
  • Handles any angle
  • Most robust

Cons

  • Slightly more material
  • Corner not precisely controlled
  • Depends on boolean performance
Best for: Prototyping, fixtures where robustness matters more than aesthetics

Miter Cut

Mode 1
Each segment cut at miter angle: │ Seg 2 │ Seg 1 │ ─────────────╲ ╲ ← 45° cut (for 90° bend) ╲ ╲───────────── Miter angle = bend_angle / 2

Cut each segment at the bisector angle so they meet precisely at the corner with no overlap.

Pros

  • Clean, precise corners
  • Professional appearance
  • No excess material

Cons

  • Complex angle calculation
  • Gap risk if imprecise
  • More cutting operations
Best for: Production tooling where corner aesthetics matter

Radius Blend

Mode 2
Fillet added at corner: │ Seg 2 │ Seg 1 │ ─────────────╲ ╲) )───────────── ╱ Smooth radius transition

Unite segments then add a cylindrical fillet at the corner for smooth transitions.

Pros

  • Smooth transitions
  • Reduces stress concentration
  • Better material flow

Cons

  • More complex geometry
  • May not suit tight corners
  • Extra boolean operation
Best for: Parts requiring smooth material flow around bends

💻 Usage

'*** Call fxZigzagBlade with corner mode as last parameter:

'*** Mode 0: Overlap + Union (recommended for most cases)
call fxZigzagBlade i_pathKurve i_partBody w_thickness 0

'*** Mode 1: Miter cut (for clean corners)
call fxZigzagBlade i_pathKurve i_partBody w_thickness 1

'*** Mode 2: Radius blend (for smooth transitions)
call fxZigzagBlade i_pathKurve i_partBody w_thickness 2

Testing Different Modes

'*** Test harness lets you try each mode:
call fxTestZigzagBlade 0   '*** Run with overlap mode
call fxTestZigzagBlade 1   '*** Run with miter mode
call fxTestZigzagBlade 2   '*** Run with radius mode

⚙️ Configuration

Parameter Default Description
w_overlapExtension 5mm How far to extend segments past bend point (Mode 0)
w_blendRadius 3mm Corner fillet radius (Mode 2)

These can be adjusted in the fxZigzagBlade.ovm macro as needed.

📐 Angle Reference

Bend Angle Miter Cut Angle Notes
90° 45° each side Most common case
60° 30° each side Acute bend
120° 60° each side Obtuse bend
45° 22.5° each side Sharp bend

Formula: miter_angle = bend_angle / 2

💡 Recommendations

Scenario Recommended Mode Reason
First-time setup / testing Mode 0 (Overlap) Most forgiving, always works
Production fixture tooling Mode 1 (Miter) Clean professional appearance
Deep-draw or forming fixtures Mode 2 (Radius) Smooth material flow needed
Complex multi-segment paths Mode 0 (Overlap) Most robust for many corners
Tight acute angles (<60°) Mode 0 or 2 Miter can create very thin edges