Laser-Cut Topography: Vertical

Considerations for this method

Pros:

Very detailed and smooth representation of terrain, especially compared to other laser-cutting methods.

Cons:

Relatively expensive and time consuming, compared to other laser-cutting methods.
Vertical surfaces, like buildings are not well articulated if sides are not parallel to face and edges of cut material.

Grey museum board most closely matches the cut edge color, but other materials can work, especially if you paint it afterwards.

Different materials may have slightly different thicknesses. Measure material thickness carefully before contouring the model.

On this page

Material options

METHOD

MATERIAL

COST ($/sf)

TIME: file prep (hr)

TIME: fab (hr)

TIME: assembly (hr)

TIME: total

MATERIAL RECYCLABILITY

Vertical laser-cut topo

1/16" grey chip (35 18x32" sheets),

with basswood dowels and acrylic for water

$41

20.5

5.5

10.5

36.5

yes

Vertical laser-cut topo

4ply grey museum (35 18x32" sheets),

with basswood dowels and acrylic for water

$111

20.5

5.5

10.5

36.5

yes

File preparation

You'll need a file with vertical contour lines at a horizontal spacing that matches the thickness of your modeling material. Use the "contour" Rhino command to generate them from NURBS surfaces or meshes of the topography and buildings.
1. If your base file does not have a surface or mesh representing the topography, you can use the RhinoTerrain plugin (available in the Software folder on Goliath) to make a 3D mesh from horizontal topography lines.
2. You can either:
  1. Contour the mesh and the buildings together,
    1. Then clean up the resulting contour curves (delete building contours which are below the surface of the topography, and remove topography curves which are inside buildings).
  2. Or, use the drape command to create a NURBS surface from the topography mesh,
    1. Then use the buildings to make holes in the new NURBS surface,
    2. And use the new NURBS surface to trim away the subterranean parts of the buildings.
    3. Then contour it all together. By trimming the surfaces, you avoid having to trim the contours as in option (i).
For keeping a clean edge, it helps to add rods for threading the layers.
1. For a large model as this one (4) square 3/16" dowel rods will work. Bass wood would work great but consider plexi rods for the areas with water.
2. Space holes for them evenly along the long side of the model, cutting through all of the contours.
For this model, we're going to add plexi for the areas that have water by nesting it between every other layer of the primary material.
1. The plexi layers should also include cutouts for rods.
2. The in-between layers should have a reveal in the areas where they meet water for a stronger visual effect.
Lay out each layer on laser bed-sized (18" x 32") sheets of material.
1. One for water to be cut on plexi
2. The rest on primary material sheets. Since the layers are being stacked, it doesn't matter which side they are cut on so you can flip and rotate layers in order to minimize material waste.

Making the model

Prepare material for the number of sheets you will need to laser cut.
1. If buying material from the GSD Store, it will already be cut to the laser bed size.
2. If buying material from other vendors, you most likely will need to cut material to the laser bed size (18" x 32").
Always test cut a small piece first to make sure that the laser is cutting the material through all the way. The edges of the cut sheets will be very visible, so use as low of a PPI setting as possible to minimize burning.
Once all sheets have been cut:
1. Stack layers in order, by threading each layer onto the rods.
2. A small amount of glue (Tacky or Sobo) will help hold the layers together.
3. Glue the plexi layers to the primary material using epoxy or super glue
4. Cut off any remaining length from the end of the rods so that they end flush with the material

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