A simple sheet metal workbench for FreeCAD

• Folding tools:

  @shaise Shai Seger
  @jaisekjames
  @ceremcem Cerem Cem ASLAN
  (@JMG1) Based and inspired by Javier Martínez's code

• Unfolding tool:

  Copyright 2014 by Ulrich Brammer <ulrich1a[at]users.sourceforge.net> AKA @ulrich1a

As a simple test case, consider the following example:

• Inputs:
  • Thickness: 2mm
  • K-factor: 0.38 (ANSI)
  • Leg length: 48.12mm
  • Inner effective radius: 1.64mm
  • Flange length: 51.76mm
• Output:
  • End to mold-line distance: 50mm

You can find a simple calculator in tools/calc-unfold.py.

You can use a Spreadsheet object to declare K-factor values inside the project file permanently. This will allow:

• Different K-factor values to be used for each bend in your model
• Sharing the same material definition for multiple objects

1. Create a spreadsheet with the name of material_foo with the following content (see this table):

   Radius / Thickness	K-factor (ANSI)
   1	0.38
   3	0.43
   99	0.5

   Notes:

   1. The cell names are case/space sensitive.
   2. Possible values for K-factor is K-factor (ANSI) or K-factor (DIN).
   3. Radius / Thickness means Radius over Thickness. Eg. if inner radius is 1.64mm and material thickness is 2mm then Radius / Thickness == 1.64/2 = 0.82 so 0.38 will be used as the K-factor. See lookup.py for more examples.

2. Use "Unfold Task Panel" to assign the material sheet.

3. Unfold as usual.

Some sort of parameters effect the fabrication process but are impossible to inspect visually, such as K-factor, which makes them susceptible to go unnoticed until the actual erroneous production took place.

In engineering mode, such "non-visually-inspectable" values are not assigned with default values and explicit user input is required. "Engineering mode" is a safer UX mode for production environments.

1. Switch to SheetMetal WB at least once.
2. Edit -> Preferences -> SheetMetal
3. Select enabled in Engineering UX Mode field.

For installation and how to use, please visit:
https://theseger.com/projects/2015/06/sheet-metal-addon-for-freecad/
Starting from FreeCAD 0.17 it can be installed via the Addon Manager (from Tools menu)

• Development repo: https://github.com/shaise/FreeCAD_SheetMetal
• FreeCAD wiki page: https://www.freecadweb.org/wiki/SheetMetal_Workbench
• Authors webpage: https://theseger.com/projects/2015/06/sheet-metal-addon-for-freecad/
• FreeCAD Forum announcement/discussion thread

• V0.2.49 03 Jul 2021: Add SubShapeBinder as source by @s-light. Thank you!
• V0.2.48 02 May 2021: Add context menu @jaisejames. Thank you!
• V0.2.47 24 Feb 2021: Add translation support by @jaisejames. Thank you!
• V0.2.46 31 Jan 2021: Small bug fixes and code clean by @jaisejames. Thank you!
• V0.2.45 24 Dec 2020: Added punch tool feature by @jaisejames. Thank you!
• V0.2.44 19 Dec 2020: Added extend feature by @jaisejames. Thank you!
• V0.2.43 01 Dec 2020: Added corner feature and map sketch to cut openings by @jaisejames. Thank you!
• V0.2.42 09 Jun 2020: Added Engineering UX Mode by @ceremcem. Thank you!
• V0.2.41 01 Jun 2020: Added Drop down Menu
• V0.2.40 24 May 2020: Added added tools for conversion of solid corners to sheetmetal by @jaisejames. Thank you!
• V0.2.34 09 Mar 2020: Rename "my commands" context menu to sheet metal
• V0.2.33 09 Mar 2020: Fix bend radius bug on sketch bends. Thank you Léo Flaventin!
• V0.2.32 02 Jan 2020: Python 3.8 update by @looooo. Thank you!
• V0.2.31 24 Apr 2019: Added better K factor control by @ceremcem. Thank you!
• V0.2.30 30 Mar 2019: Added Fold-on-sketch-line tool by @jaisejames. Thank you!
• V0.2.22 24 Jan 2019: Fix some typos, Issue #54
• V0.2.21 20 Jan 2019: Fix some typos, Issue #52
• V0.2.20 10 Jan 2019: Added sheetmetal generation from base wire by @jaisejames. Thank you!
• V0.2.10 01 Nov 2018: Merge new features by @jaisejames. Thank you!
  • Added Edge based selection
  • Added Auto-mitering
  • Added Sketch based Wall
  • Added Sketch based Guided wall
  • Added Relief factor
  • Added Material Inside, thk inside, Offset options
• V0.2.04 21 Sep 2018: Fix K-Factor bug
• V0.2.03 20 Sep 2018: Merge @easyw PR: Add separate color for inner sketch lines. (issue #46). Change Gui layout
• V0.2.02 15 Sep 2018: Add color selection for unfold sketches (issue #41)
• V0.2.01 15 Sep 2018:
  • Fix bug when not generating sketch (issue #42)
  • Support separate color for bend lines (issue #41)
• V0.2.00 04 Sep 2018: Make SheetMetal compatible with Python 3 and QT 5
• V0.1.40 20 Aug 2018: Merge Ulrich's V20 unfolder script - supports many more sheet metal cases and more robust
• V0.1.32 25 Jun 2018: New feature: Option to separately unfold bends. Thank you @jaisejames!
• V0.1.31 25 Jun 2018: Support ellipses and parabolas, Try standard sketch conversion first
• V0.1.30 25 Jun 2018:
  • New feature: Generate unfold sketch with folding marks. Issue #33. Thank you @easyw!
  • New feature: K-Factor foe unfolding is now editable. Issue #30
• V0.1.21 19 Jun 2018: Fixed back negative bend angles, restrict miter to +/- 80 degrees
• V0.1.20 19 Jun 2018: (Thank you @jaisejames for all these new features!!)
  • Add bend extension to make the bended wall wider
  • Add relief shape selection (rounded or flat)
  • Double clicking on a bent in the tree view, brings a dialog to select different faces (good when editing the base object breaks the bend, and new faces need to be selected)
  • Setting miter angle now works with unfold command
• V0.1.13 10 May 2018: Change unbending method so shape refinement can work.
• V0.1.12 25 Mar 2018: Allow negative bend angles. Change XPM icons to SVG
• V0.1.11 01 Feb 2018: Fix Issue [#23][23]: when there is a gap only on one side, an extra face is added to the other
• V0.1.10 11 Nov 2017: Add miter option to bends. By @jaisejames
• V0.1.02 22 Jun 2017: Fix nesting bug, when saving and loading file
• V0.1.01 03 Mar 2017: Support version 0.17 (starting from build 10423)
• V0.0.13 07 Sep 2015: Add negative gaps for extrude function. (per deveee request)
• V0.012 07 Sep 2015: Fix issue submitted by deveee
• V0.010 13 Jun 2015: Add Ulrich's great unfolding tool. Thanks!!!
• V0.002 12 Jun 2015: Fix Save/Load issues
• V0.001 11 Jun 2015: Initial version

GPLv3 (see LICENSE)