isel_icv4030:engraving_detailed_images

Engraving detailed images

Fusion 360's sketch engine is not built for vector images with lots of detail. Here are some tips based on this article to try make it work. The key is to keep sketches simple. That's why we'll try to spread the information over multiple sketches. We will split up the vector image into multiple tiles in Illustrator.

Keep the document units the same throughout the workflow (mm for example)

  • In Illustrator, simplify the vector drawing as much as possible.
  • Separate elements into different layers
    • Clusters can be cut (illustrator: divide option in the pathfinder) and separated into different layers. For this to work, the cutting object shouldn't be a closed shape.
  • Export from Illustrator to DXF (exporting to DXF from Inkscape resulted in strange artefacts).
  • Import in Fusion 360 with the option of One sketch per layer option enabled.

For cutting the area in-between the shapes (to use as a stamp for example).
Note to future self: If an image is used as a stamp, mirror the image(!)


Embossing stamp in aluminum. Not mirrored.


Embossing stamp in Trespa. Mirrored.

  • Set the document units to mm
  • Draw guides to define where the tiles should go:

    Notice the double lines. This is overlap so we're not running into problems cutting thin walls on the edges.
  • This process ruins the vector image. So always work on copies of it.
  • Draw squares where you want the tiles to be (with a bit of overlap). Give them a stoke colour that's different than the image vectors (red for this example):
  • Select the image vectors and the rectangle.
  • click 'divide' in the pathfinder:

  • The two layers have merged into one. You can delete the empty one:
  • Ungroup the square and the image.
  • Select a part of the image (a back shape in this case) and go to Select > Same > Appearance. Delete it:
  • The black shapes are internal cavities that weren't reached by the red shape. Select them and give them the same outline thickness and color. (Probably not necessary). I think this is because the original file already had those double lines.
  • Use the outline view mode to delete objects outside the tile area:
  • Give this layer a clear name. Hide it and repeat for the other tiles:
  • After all the contours for the tiles have been made, select all the vectors and export:
    • Go to File > Export > Export as…. Set the format to dxf and click Export.
    • In the export options, make sure a unit represents a millimeter. Check the option Export Selected Art Only. Click OK:

Preparing the 3D models

  • Import one sketch per layer:
  • Draw a frame around every sketch, so the boundary can be raised up. This is necessary to calculate the toolpaths. These boundaries will be milled away by the overlapping areas.
  • Hide all but 1 sketch.
  • Create a tile
    • Extrude the base
      • Select the extrude option and select the whole sketch (drag right-to-left).
      • Extrude downwards for the base.
    • Extrude the drawing elements
      • Select the extrude option and select the drawing elements
      • Extrude upwards.
      • Set the operation to Join, so top and bottom will be a single object.
    • repeat for all tiles:

Creating toolpaths

  • Create an object with the dimensions of the stock material & position it accordingly in relation to the tiles.
  • Machine all tiles one by one.
    • Create a setup, referencing the just created object for the stock material. Only select one tile as the object to machine. Duplicate this setup for each time. Make sure to use the same origin point in all setups.
    • Rough out most of the material using a 3D adaptive strategy with a 3mm flat endmill. Use ±0.5mm stock to leave so fine elements won't get pulled out while rouging.
    • Then engrave: select the contours from the sketch instead of the 3D model. Select the sketch lines manually (it cuts the insides instead of the outsides of the shapes when using selecting all the contours with the box select tool). Select all lines except the outer rectangle.


3D model


Contour selection


Toolpaths


Stock simulation

  • isel_icv4030/engraving_detailed_images.txt
  • Last modified: 2021/10/04 06:33
  • by formlab