Craft Corner: Laser Cutting Pt. 1

Laser cutting is something that I use a lot in my prototyping process because it is a (relatively) easy way to make a 3D object with a certain degree of speed and precision, but it can be a tricky thing to navigate if you’re just starting out with digital prototyping. There is a lot of ground to cover so this post will be separated into 2 parts. The first will cover basics such as vectors, file preparation, materials, and ordering. The second part will get into the nitty gritty of prototyping with a laser cutter, taking a look at various techniques, types of joinery, and resources.


Overview


How does a laser cutter work? Basically, a laser beam is reflected off a lens that is focused on a material, moving on an XY (and sometimes even Z) axis as it burns through that material in order to cut through or take away surface material.

A laser cutting machine is generally capable of doing 3 things: cutting, scoring, and engraving (also known as raster etching). What’s the difference between the 3? Cutting is pretty self explanatory - the laser cuts through the material by following lines drawn on a computer program. Scoring is essentially the same thing as cutting but using a lower power level so that the laser doesn’t cut all the way through. Raster etching is similar to scoring, only instead of following a line it renders a black and white image on the surface by going back and forth and cutting material away, similar to how a printer cartridge moves back and forth while leaving ink on the surface of a page. If you want an engraving that has areas filled in, you would only be able to do that with a raster etching.

Vectors and File Preparation


One important thing to note is that laser cutting and scoring require graphics in the form of a vector drawing, whereas a raster etching can handle other types of files, like .jpgs for example. However, if you’re doing something that only requires linework, you’re much better off drawing it as a vector because scoring a line takes significantly less time than engraving a line from a raster drawing. Why? Because instead of following a line around a shape, the laser head has to go back and forth dropping little dots like a printer. Keep in mind that the depth of scoring or engraving can also be controlled in the power settings, so you can request a lighter or heavier engraving, or even make use of both to create contrast.


But what is a vector, anyway? A vector graphic uses lines and curves to create shapes rather than using pixels. This allows the image to scale up and down without losing resolution or becoming “fuzzy.” Text is usually rendered as a vector, which is why it doesn’t get blurry when you zoom in, but in order to cut or etch some text, you will need to convert it to an outline, otherwise it would be raster etched by default. In Illustrator you can do this by selecting the text and going to Type > Create outlines. Note, however, that once you convert the text you will no longer be able to edit it. You will also need to set your line thickness to either “hairline” or .001, depending on the program you’re using. Otherwise, it may not be properly interpreted by the machine and could be engraved instead.

Popular programs for drawing with vectors are Adobe Illustrator, AutoCAD, and Rhino. I’m not going to teach you how to use these, but there are plenty of great YouTube tutorials. (If you are looking to hire someone to do this for you, it is a service I provide on a freelance basis, so feel free to contact me about your project.) Most laser cutting vendors offer this service for a fee as well. You can also read more about vectors here.