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shaise / FreeCAD_SheetMetal

A simple sheet metal workbench for FreeCAD
http://theseger.com/projects/2015/06/sheet-metal-addon-for-freecad/
GNU Lesser General Public License v2.1
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[Feature] Support for folding marks (for the laser cutter) #187

Open luzpaz opened 3 years ago

luzpaz commented 3 years ago

reference: https://twitter.com/carribeiro/status/1368340185323352064

ceremcem commented 3 years ago

I observed no benefit of marking the bend points with the laser cutter. Efficient approach (that I use) is

  1. Precisely calibrate the distance between punch and back gauge
  2. Apply the correct force

I obtain bends with 0.02mm of error with that approach.

image

carribeiro commented 3 years ago

This request is related to #186. Laser-cut cardboard boxes are easier to fold if the material is scored lightly with the laser cutter. It's usual to use a sparsely dotted line because a solid line weakens the cardboard. That's especially necessary when the fold is made against the direction of the flutes of the cardboard's structure.

As it is now, the workflow is:

  1. design the box with the sheet metal workbench;
  2. unfold the box;
  3. generate a 2D drawing of the box, and export (SVG or DXF are the most common formats for lasers now);
  4. open the drawing in a 2D tool of choice, and ADD THE FOLDING LINES MANUALLY.
  5. cut the shape with the laser for folding.

NOTE: the 2D app of choice is usually CorelDraw, Autocad, or Inkscape. FreeCad itself or other open-source CAD could be used - but most laser cutting shops would probably end up using CorelDraw as far as I know for practical/historical reasons.

All this work is necessary because the scoring line is not a 3D part (although we could probably make a few thin holes with unfolding). In practice it's even a bit harder because some lasers (all that I know really - there may be exceptions) don't know how to deal with dotted lines and end up with a solid scoring line that weakens the cardboard.

I don't really have a plan on how to do it in FreeCAD but some possibilities are:

  1. As said above, make thin holes on the fold line, and (somehow) convert the holes into a single stray line segment when generating the technical drawing or exporting the vector
  2. Investigate whether it's possible to generate the lines directly when generating the drawing.
carribeiro commented 3 years ago

I observed no benefit of marking the bend points with the laser cutter. Efficient approach (that I use) is

  1. Precisely calibrate the distance between punch and back gauge
  2. Apply the correct force

I don't have the same equipment that you have to make folds. I do it by hand using aluminum L bars or MDF punchers cut to size. The folding lines make it easier to fold larger boxes. I know it may weaken the cardboard, but it's the most practical way to make it without requiring another equipment (specially for one-off custom boxes, or for prototypes).

MisterMakerNL commented 3 years ago

OK I been making a box in sheetmetal today. And it goes decently, although it is hard to keep an overview. But once I have a box I can re-use it every-time. I looked into professional box design software, and they are all just as expensive as normal CAD software. And for a small maker that makes a couple of boxes a year not viable. Like my boxes would cost 10 euro a box. I cannot charge 10 euro a for a box.

I currently design my boxes in Blender, but that has it cons. Like missing parametric design. Every-time I change my dimensions I have to scale stuff, which screw up my gaps and hooks that need to stay the same. So doing this in Freecad would be way better. I also tried this in Fusion360 when I was still using that and it didn't work. At a moment Fusion just said screw this, this is to complicated I am bailing out. I noticed this also happens in Freecad to an extend. But I got further than Fusion so that is awesome! And probably with more work I can get a decent box design in it. This is my design: afbeelding This is freecad when it had enough: afbeelding

luzpaz commented 3 years ago

anyone interested in spearheading this?

luzpaz commented 3 years ago

@oficinerobotica can you weigh in since you made a cardboard box clip with LinkStage3

luzpaz commented 3 years ago

@jaisekjames care to weigh in?

luzpaz commented 3 years ago

@HaasNL2 are you planning to develop this feature?

MisterMakerNL commented 3 years ago

@luzpaz To bad I am not a developer. And don't have the time to become one. If you really want this it could be interesting to setup a gofund me and find a good developer that has the time to do this. Or just donate to freecad and ask there.

carribeiro commented 3 years ago

I'm still in the loop. At the moment have some real life things going on, I`m moving my shop over this week, lots of things to do. But I think I'll be back in a few days.

Carlos Ribeiro Mentoria & Consultoria em Projetos de Inovação about: https://about.me/carribeiro mail: @. twitter: http://twitter.com/carribeiro medium: @. linkedin: https://www.linkedin.com/in/carlos-ribeiro-6a7b8b1

On Sat, May 8, 2021 at 4:08 AM Haas @.***> wrote:

@luzpaz https://github.com/luzpaz To bad I am not a developer. If you really want this it could be interesting to setup a gofund me and find a good developer that has the time to do this. Or just donate to freecad and ask there.

— You are receiving this because you commented. Reply to this email directly, view it on GitHub https://github.com/shaise/FreeCAD_SheetMetal/issues/187#issuecomment-835161386, or unsubscribe https://github.com/notifications/unsubscribe-auth/AABVDTAW574MOFJ7TKXIQT3TMTPQJANCNFSM4YXG4FFQ .

luzpaz commented 3 years ago

bump, any interest for someone to work on this?