Unrolling Components

Bend Correction Table (BCT)

Builds an unroll compensation strategy from a press-brake correction table. Each row describes one tooling and material combination: a thickness, an inner bend radius, a bend angle, and the length correction to apply. The flat length of a bend is the sum of the adjacent flange lengths plus that correction, which is normally negative because real bends shorten the developed length. For each bend the row with the closest thickness and inner radius is used, interpolated along the angle. Wire the output into the Unroller's Compensation Strategy input.

Inputs

Outputs

Tips

• 0.5 is a safe neutral fallback K-factor for most steels.
• Sample your table densely around the angles you actually bend; sparse tables interpolate but cannot extrapolate.
• Use this when your shop floor already has a calibrated correction table — usually more accurate than guessing a K-factor.

K-Factor Table (By Angle + Direction) (DSKF)

Maps each bend angle and direction pair to a K-factor, for materials that behave differently folding up versus down. Supply parallel lists of angles (in degrees), K-factors, and directions. Wire the output into the Unroller's Compensation Strategy input. Use K-Factor Table (By Angle) if direction doesn't matter.

Inputs

Outputs

When to Use

Use when the 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]

K-Factor Table (By Angle) (KFT)

Maps bend angle to K-factor using a lookup table, for materials whose neutral axis shifts with the angle. Supply parallel lists of angles (in degrees) and K-factors, optionally interpolating between entries. Wire the output into the Unroller's Compensation Strategy input. Use K-Factor Table (By Angle + Direction) if the material behaves differently folding up versus down.

Inputs

Outputs

How It Works

• Maps specific bend angles to K-factor values.
• Looks up the K-factor based on the actual bend angle during unrolling.
• Uses the fallback value if the angle is not in the 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 (a warning is issued).

Example

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

Reroll (Reroll)

Maps flat-layout points and curves back onto the 3D sheet, and cuts closed flat curves through the sheet solid. Inverse of the Unroll Mapper.

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Outputs

Unroll Mapper (UMap)

Maps 3D points and curves from the sheet onto the flat layout, matching each one to the face it sits on. Also exposes the rigid transform and source plane for every flange, so you can map or compose further geometry yourself.

Inputs

Outputs

Unrolled Bend Info (UBI)

Reads per-bend manufacturing information out of an Unroll Result for documentation and press-brake setup. For each bend it reports the angle, fold direction (up/down), bend allowance, local radius, the bend's center point on the part, and a label. Bend centers are handy for placing dimension text or arrows in a drawing.

Inputs

Outputs

Tips

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

Unroller (U)

Unfolds a sheet into its flat pattern. Bend lengths are compensated so the flat folds back to the correct dimensions, using either a static K-factor or a compensation strategy (K-factor table, bend deduction, or press-brake correction table). Also returns bend axis lines and bend region outlines for drawings.

Inputs

Outputs

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)

Tips

• Start with K=0.5 for initial tests.
• Wire a K Factor Table into the Compensation Strategy input for angle-dependent compensation (more accurate).
• The Bend Axes / Bend Regions outputs are useful for creating technical drawings.