Introduction: Welcome to Laser Cutting
Laser cutting is nothing short of a magical tool for makers. Laser cutters are precise and versatile, allowing you to make a project as simple as personalized drink coasters or as advanced as quadcopter drones. It's also a great way to learn to design things that are made up of 2D panels, and with that skill, you can make just about anything.
If you don't have access to a laser cutter, it's no problem. Ponoko is an online service bureau that will cut out your projects for you in a wide variety of materials. They're reasonably priced and they do excellent work.
In this class, we'll learn laser cutting by making 2 projects...
Project 1: Tissue Box Cover
Using Makercase, a web app that generates a laser cut box panel layout by entering dimensions, we'll make a tissue box cover.
Project 2: 2D Puzzle
Next, we'll learn the basics of 2D design in Adobe Illustrator and Autodesk Graphic by making a 2D puzzle. We'll draw the puzzle piece shapes and overlay a raster image for etching.
Step 1: A (Very) Brief History of Laser Cutting
“Laser” is an acronym for "light amplification by stimulated emission of radiation”. Originally theorized by Albert Einstein in 1917, It’s basically just highly focused, highly amplified light. A stream of photons from a flashlight has a phase and amplitude that vary randomly with time and position, meaning coherence only happens over very short distances. A laser, on the other hand, has a high degree of coherence, meaning the light has limited diffraction, is polarized, and has a single, consistent frequency over a long distance.
Think of it this way: a magnifying glass can burn a leaf by focusing sunlight on a single spot, but if you move it out of focus by a tiny bit, it stops burning. The spot you’re burning is about 1/4” across, and you can burn at a depth of less than a millimeter.
With a laser, you can focus the light to a tiny spot about .004” across, and you can burn through 3/4” thick plywood without the beam spreading out.
Laser cutting is basically just a laser on a CNC gantry. The machine takes a set of vectors, points, or raster images in the form of G-code and moves the laser around to cut and / or etch into the material.
Laser cutting was first developed by the Western Electric Engineering Research Center in New York in 1965 as a way to drill holes through diamond dies. Since then, it’s been used for a number of industrial manufacturing applications. In 1988, Epilog founded with the concept of making laser cutting available to small businesses and home craftsmen. With the release of their Zing model in 2008 for less than $10,000, laser cutting quickly became accessible for makers everywhere.
Step 2: What Can You Do With a Laser Cutter?
With a typical laser cutter, you can cut a variety of materials such as paper, wood, fabric, leather, and plastics. You can also etch these materials, glass, metals, and even food like chocolate or tortillas.
The use of a laser cutter to a maker comes down to three things: precision, repeatability, and speed. Once you've got your design worked out and your settings dialed in, you can produce lots of exact copies of the same piece to your heart's content.
Step 3: Etching
Etching is most commonly used to apply graphics to a surface. Name tags and plaques are usually laser-etched, but by using a raster image (which we'll cover in Lesson 3), we can also apply detailed images to surfaces.
With Carleyy'sLaser Cut Beverage Coasters, the etching is done directly onto the surface of 1/4" plywood, leaving a burnt layer of veneer with sharp edges based on an image made in Adobe Illustrator. The edges of the coasters are also laser cut, and both the etching and cutting can be combined in a single operation on the laser cutter.
Step 4: Cutting
Although etching can be done on many different shapes and materials, cutting is almost exclusively done on flat panels with uniform thickness. Cutting can be used to embellish graphic objects like signs or works of art, but it's also very useful for creating 3D objects by combing two or more cut panels.
The kerf of a laser cutter is so small (about .004" or .1mm depending on the material) that it's easy to cut sharp interior corners and many other intricate, finely detailed shapes.
HTMF Metal Pizza's Dremel Chop Saw is a great example of how powerful a laser cutter can be in the hands of a maker with solid 3D design skills. With a single sheet of 1/4" plywood and a little brass tubing, he created a working chop saw with a Dremel tool for precise small pipe cutting.