Lasercutting for Designers

Posted by on Aug 2, 2012 in Blog, Tutorials | No Comments

In a nutshell, a lasercutting machine works by shooting a high-powered laser onto a flat material. The laser will follow the path of the file that you give it; it can also create a raster effect by tweaking the strength of the laser. The two main reasons I love the lasercutter is that it is quick AND accurate.

Table of Content

Pro’s and Cons of the lasercutter

Pros

  • Low software requirements
  • Highly accurate
  • Wide variety of materials
  • Repeatable process
  • Quick turnaround time

Cons

  • Restrictions on flat materials
  • Burn marks
  • Cannot cut PVC and other harmful fume containing materials
  • Usually costs by the minute (so intricate files = lots of $$$)

Machine techniques

Raster Image This first technique is the easiest and can be done with an image file type (like a JPEG, PNG or Bitmap). This method makes the lasercutter act as a normal ink printer, just equipped with a laser! It goes back and forth and burns the area where the image is located. Darker areas are burned more than lighter areas of the image. For this technique, it is important to pick a material that allows for different tones through the burn marks. I highly recommend creating a small test strip with the material you want to use, containing an image that has a gradient with a black value from 0 to 255. This method is the most expensive method due to the repetitive passes the lasercutter has to do to get the different tones. Vector Cut What this cut does is to go all the way through the material. A factor to take into consideration when cutting is the thickness of your material. From personal experience, don’t do anything over 0.3inches. When the material is too thick, the laser needs to go at a slower pace with higher power to go through the material. This results in a non-smooth cut due to excessive burning. The straight edge that you wanted turns into a wobbly charcoal edge… An example of this can be seen when you scroll down to machine artifacts. Vector Etch By combining the two methods above, this one follows a vector line while rastering. This creates a hairline cut that does not go through the material. Since the laser follows a vector path, the line becomes as smooth as you make it. It is important to realize that vector files and image files are read differently by a lasercutter. For a raster image, use an image Teletype like JPEG, PNG or Bitmap. The two other methods need a vector-based file type like Adobe Illustrator, Corel Draw and AutoCAD. Depending on the place that you go to, make sure that you are able to produce the right file type for their machines. The best thing to do is to ask what file type they prefer to deal with.

Materials

As for possible materials to use, there are extensive lists out there, like this one which is a place I usually go to in Toronto for my lasercutting services (and no I didn’t get paid to put this here!). Yet again, not every operator is as willing to cut every single material so the best choice is to talk to them and see what the possibilities are. However the two biggest bo-boo’s are too thick/solid materials or materials with harmful fumes. Machine Artifacts Materials act differently under the lasercutter. An example is how plywood gets burned at the edges compared to plastic which usually achieves a clean finish. I cannot emphasize enough on doing a test cut. Make some dummy cuts onto a small sample of the material to see the effects a lasercutter has on it. Only then can you really understand how the material reacts with the lasercutter.

Miscellaneous

Raster before Vector Lasercutting monitors usually do this but if you have both raster and vector on the same file, just make a small remark about doing the raster stuff before the vector cuts. This prevents pieces from shifting around during a raster from to the vector cut that might have been done. Vector Line Colors Depending on what color the vector lines are, the lasercutter will interpret them differently and do a corresponding action. One common element that they have is that they prefer RGB instead of CMYK. The lines are solid colors (like 100% R, G, B or Black). At OCADU, B = engraving / rastering while R = first cut B = second cut G = third cut. At Toronto Lasercutting Service, B = Raster, R = cut line, B = etch line, G = cut / etch line #2. The bottom line is, make sure you know what the different colors do in your file before submitting it, because each place has their own system that they follow!

Conclusion

If you haven’t tried it, then I recommend trying it! The lasercutter is a go-to tool that performs like you tell it to do. It has low software requirements (image/vector file) which gives the machine a low learning curve. However, don’t be fooled by the simplicity of the machine, by pushing its limits and taking advantage of this highly accurate and consistent beast, one is capable of making some awesome stuff!

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