What’s the difference between Laser Cutting and 3D Printing?

Now, you might be thinking that the answer to this question would be obvious. After all, one is about cutting while the other is about printing, right? Well, it’s not as easy as that.

Both processes involve using a powerful laser to craft a shape, but one laser burns through material while the other helps create it, so what’s going on here?

The answer involves both the materials the laser is interacting with, and the wavelength of the laser beam being used. Before we get into the specifics, let’s look at what’s involved in both of these techniques.

Laser cutting in focus

The process was initially devised in university laboratories in the 1960s as an accident, when researchers saw that an intense beam of light could, if controlled, burn through solid objects.

Eventually a combination of light beams, partial mirrors and gases were combined to form what we now know as modern laser cutting machines. Recent developments have led to laser cutters that can pierce through steel many inches thick with a smooth cut line and fine detail.

3D printing primer

3D printing also uses the power of lasers to forge new materials into shape. In 1987 Chuck Hull used an ultraviolent laser to cure a thin layer of resin that was designed to solidify when exposed to light. This was the beginning of additive manufacturing, where new shapes are added together to make one solid object.

Since then, the process has been refined and expanded to let people reshape a wider range of complex materials with even finer precision and with more detail. Plastics, resins and metals can now be used as 3D “ink” for the printer, which is heated at a precise temperature enough to be added seamlessly to the existing object.

Even biocompatible resins, which react to muscle movement and other human input, are a great match for 3D printing and can make new limbs that would be otherwise impossible to create.

The big difference

So now that we know what the two systems are about, how come lasers can cut in one instance but create in the other?

What we know as a “laser beam” is really a focused beam of light. Every light you see, from the sun to the lights in your room to the screen you’re reading this on, has an individual wavelength that informs how strong the light is. 3D printers typically use a laser beam rated at 1,070 nanometres which is near the infra-red range. Laser cutters start at 1,030 nanometers, which is still pretty close, so that doesn’t explain it either.

The difference is about how much energy is being packed into the laser.

3D printers have a laser beam rated at usually 500 watts or so. It’s enough energy to make the laser beam consistent and strong enough to melt the material being fed into it at the right temperature.

Laser cutters, on the other hand, pack at least 10 times the amount of power into the beam, charging it up enough to turn it from a warm light to a blade of light powerful enough to cut through thick steel. It’s not unusual to see a steel laser cutter with 6 kilowatts of power coursing through its electronic veins.

At ShapeCUT we work with laser cutting machines capable of any size project you can imagine, and enjoy the technical challenge of making your dreams a reality. Talk to the team at ShapeCUT today to find out more.