TFDL Makerspace Training
Designing for Laser Cutting
Using Existing Designs for Laser Cutting
There are many free online designs available if you do not wish to create something from scratch. Here are a few sources for free laser cutter designs:
Please bear in mind these designs may not work if they were designed for a different material, or rely on precise kerf adjustments, particularly if you modify the size of the original design.
Creating Your Own Design
Creating Your Own Designs
Our laser cutter can perform cuts, scoring, and etches. Cuts go all the way through the material, and follow a path. Scoring also follow paths, and can be used to make simple linework designs. Etches are used to take rasterized images or solid areas of vector art, and burn them onto the surface of the material. They are also the most time consuming, as the laser has to pass back and forth many hundreds of times per inch to create the image.
All of the paths needed for cutting and scoring need to be vectors. Vector artwork can be created using software such as Inkscape, Adobe Illustrator, Fusion360 or Rhino3D.
Raster images (shown in blue) will be burned, Vector paths (shown in red) will be cut.
Most laser cutters use different colours to differentiate which paths are for cutting, and which are for scoring or etching. Make sure paths for cutting are all set to red. Scoring should be green, and etching should be blue or grayscale. It is recommended that prior to being added to the design, images are converted to grayscale. This will give a better sense of what the final output will look like.
Kerf and Material Thicknesses
Even though a laser is very precise, it is burning away material any time it makes a cut. This small amount of material removed by the cutting process is called a kerf. Even a small kerf can cause parts to fit slightly loose.
Kerf varies from material to material, depending on thickness and density. For example: a 20mm x 20mm square cut from our 3mm Baltic Birch measures 19.85mm x 19.85mm. Kerf is calculated by subtracting this difference and dividing by 2. This gives a kerf of .075mm. Because this is such a small value, designs to not need to account for kerf unless you want extreme precision. If you are intending to make a box and glue the pieces together, accounting for the kerf will likely not matter. If you want to create a box held together by friction, it is recommended you modify your design for the kerf. Additionally, the material thickness should be accounted for when creating interlocking joints. For instance, if our 3mm Baltic Birch measures 3.47mm thick. To create perfectly meshed finger joints for our “3mm” Baltic Birch, the fingers need to be extended 0.47mm + .075mm (additional material thickness + kerf), and then widened by .075mm (kerf).
Current kerf and material thickness values:
3mm Baltic Birch:
Kerf: 0.075mm
Thickness: 3.47mm
3mm Acrylic:
Kerf: 0.075
Thickness: 3.10mm
Tips:
- Do kerf adjustments and fillets / chamfers last.
- Make a copy of your design prior to applying any kerf compensations. If you change materials, or the kerf changes, it will be easier to make new kerf compensations if you can quickly go back to your original design.
- Be sure to align and embed any raster images in your design. If the image is not embedded, it will not be available for etching.
- Although many formats are supported, we have found .PDF consistently provides the best results.
- Stroke width is ignored. Ctryl + Y in illustrator will show just paths.
- Unless using a special font for stencils, text should be etched. Do not cut text (because letters like e’s and o’s will only show as a silhouette, and be missing the pieces inside the letter).
