Unrolling Components

Components for generating flat patterns with bend compensation

Unrolling Components

Unroller (U)

Unrolls a Sheet into its flat pattern using bend compensation strategies.

Inputs

  • Sheet (S) - The sheet to unroll
  • Compensation Strategy (CS) - Bend compensation method
  • Static K-factor: number 0-1
  • Or use K Factor Table, K Factor Direction, or Bend Deduction components
  • Back Side Up (BSU) - Use opposite side of root face (default: false)
  • Thicken (T) - Creates 3D thickness in flat pattern (default: false)

Outputs

  • Unrolled (U) - Flat pattern Brep
  • Bend Axes (BA) - Lines showing bend centerlines
  • Bend Regions (BR) - Surface areas showing bend zones
  • Unroll Result (UR) - Detailed unroll data (for Unrolled Bend Info)

K-Factor Explained

K-factor represents where the neutral axis is during bending:

  • 0.0 = Neutral axis at inside radius (material stretches more)
  • 0.5 = Neutral axis at centerline (symmetric)
  • 1.0 = Neutral axis at outside radius (material compresses more)
Typical values: 0.3-0.5 for most metals

Tips

  • Start with K=0.5 for initial tests
  • Use K Factor Table for angle-dependent compensation (more accurate)
  • Bend axes/regions useful for creating technical drawings

K Factor Table (KFT)

Creates angle-dependent K-factor compensation for more accurate unrolling.

Inputs

  • Angle (A) - Bend angles in degrees (0-360°)
  • K Factor (K) - Neutral axis position (0-1) for each angle
  • Fallback (FB) - Default K-factor for unmapped angles (default: 0.5)
  • Allow Interpolation (AI) - Ilnterpolate between defined angles (defaut: false)

Outputs

  • Compensation Strategy (CS) - K-factor lookup table for Unroller

How It Works

  • Maps specific bend angles to K-factor values
  • Looks up K-factor based on actual bend angle during unrolling
  • Uses fallback value if angle not in table

Tips

  • Get angle/K-factor pairs from material testing or manufacturer data
  • Interpolation creates smooth transitions but may not match real behavior
  • Duplicate angles use the last provided K-factor (warning issued)

Example


Angles: [30, 60, 90, 120, 150]
K-Factors: [0.35, 0.38, 0.42, 0.45, 0.48]

Direction-Sensitive K-Factor (DSKF)

Creates K-factor compensation that varies by BOTH bend angle AND direction (up/down).

Inputs

  • Angle (A) - Bend angles in degrees
  • K Factor (K) - Neutral axis position (0-1) for each entry
  • Direction (Dir) - "up" or "down" for each angle-direction pair
  • Fallback (FB) - Default K-factor when no match found (default: 0.33)
  • Strict Mode (SM) - Error on undefined combinations vs. use fallback (default: false)

Outputs

  • Compensation Strategy (CS) - Direction-aware K-factor strategy

When to Use

Use when material shows different bending behavior for upward vs. downward bends (grain direction, rolling direction, etc.)

Tips

  • More accurate but requires more test data
  • Strict mode ensures all bend combinations are explicitly defined
  • Good for high-precision applications

Example


Angles: [90, 90, 120, 120]
K-Factors: [0.42, 0.38, 0.45, 0.41]
Directions: [up, down, up, down]

Bend Deduction Compensation (BDC)

Creates compensation using bend deduction values instead of K-factors.

Inputs

  • Bend Deduction (BD) - Deduction values for each angle
  • Angle (A) - Corresponding bend angles in degrees
  • Strict Mode (SM) - Interpolate for undefined angles vs. fallback (default: false)
  • Fallback to Constant K (C) - K-factor for angles >179° (default: 0.5)

Outputs

  • Compensation Strategy (CS) - Bend deduction strategy

Bend Deduction Explained

Bend deduction is the amount of material "consumed" during bending. Instead of calculating neutral axis position, you directly specify how much to subtract from flat length.

Formula:

Flat Length = Outside Setback + Outside Setback - Bend Deduction

Tips

  • Alternative to K-factors; some manufacturers prefer this method
  • Extract values from material testing or CAM software
  • Interpolation can smooth transitions between angles

Unrolled Bend Info (UBI)

Extracts detailed bend information from unrolled sheets for documentation and manufacturing.

Inputs

  • Unroll Result (UR) - Output from Unroller component

Outputs

  • Bend Angle (BA) - Formatted bend angles with labels (e.g., "B-1: 90°")
  • Bend Direction (BD) - Direction of each bend (Up/Down)
  • Bend Allowance (BA) - Calculated bend allowance for each bend
  • Bend Radius (LBR) - Local radius at each bend
  • Bend Center (BCL) - Point location of each bend center
  • Bend Label (BL) - Text labels for annotation (B-1, B-2, HB-1, etc.)

Tips

  • Use to generate bend specifications for press brake operators
  • Bend centers useful for positioning annotation text/arrows
  • Labels follow convention: "B" for regular bends, "HB" for hem bends
  • Export to spreadsheet for manufacturing documentation

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