Recently my shop was looking at replacing our CNC table with a newer model. So of course, we also wanted to take a look at other methods of shape-cutting materials in addition to a traditional CNC router. Laser, water-jet and plasma cutters are all in common use, but we wanted to know more. I started out with a visit to a company that creates 3-D exhibits and sculptures, since they make much more extensive and varied use of various cutting technologies than we do. The company is 3D Services, located in Burnaby, BC.

During a tour of their large, modern plant, I was impressed by the range of specialty items that they produce and the quality of their work. However, I couldn’t help but notice that there was no automated cutting equipment in evidence, yet most of the work that I saw there had been shape-cut. The answer was simple—even though they create jobs that require use of all of the various technologies, and each type of cutting device has its own specialty uses—they found that for them it was not practical to own all of those devices; so instead they choose to foster good relationships with various reliable suppliers who own the required equipment for a given job.

Their logic is that if they bought one type of cutting instrument, they would then try to use it for as much of their shape-cutting as possible in order to make the most of their investment. But that would mean that some of their projects were being cut with a less-than-ideal piece of equipment for that particular job. That also means that it is important that they fully understand which technology should be used when. Also, other shops may not have as varied a usage for the equipment and may want to make a purchase, so let’s look at the pros and cons of each type.

CNC ROUTERS

CNC routers are the most common automated cutting device used by sign and display shops. The equipment is relatively inexpensive compared to other types, doesn’t require any specialty environment and is fairly easy to operate. While they work better on soft materials like foam, woods and plastics, they can also cut aluminum in a pinch. Edges come out relatively clean, although Plexiglas develops a frosted edge, not clear. Letters and shapes with sharp edges tend to get scalloped inside corners from the router tool, which some might consider a major drawback. 

Surface engraving is also possible, and the newer five-axis machines can simulate three-dimensional carving as well, making it a very versatile piece of cutting equipment. When buying a CNC machine, take note that many machines are optimized for cutting specific types of materials, so a machine designed for foam cutting, for example, will not work as well for cutting aluminum. And a machine meant to be a jack-of-all-trades will not be perfect for any task.

LASER CUTTERS

Laser cutters come in a huge range of sizes and laser strengths—with an equally large range in pricing. They are also clean and easy to operate. Edges are smooth and even, leaving Plexiglas with a clear polished edge. Laser cutters also work well with most metals and plastics, although it can leave a scorched edge on wood (a nice effect, in certain cases). Shiny metals, however, cannot be cut because the laser beam reflects off of the mirror surface. Lasers can also be used for surface etching with very fine detail. They are relatively slow compared to a CNC router, and when cutting plastics they also emit harmful gases that must be discharged and vented safely.

PLASMA CUTTERS

Plasma cutters, like lasers, leave a nice shiny, polished edge on metals (including mirror finished metals). They do a very quick, efficient job, however they only work on metal and cannot do etching. They are also cost effective and easy to use, but need a large amount of room in which to operate.

WATERJET CUTTERS

Waterjet cutters are big industrial units. Large, expensive, noisy and messy, they need their own dedicated space to operate in. The water is contaminated by the metal shavings and has to be sent for hazardous waste removal. However, they can cut through huge stacks of metal like so many piles of butter. The edges are not the cleanest, and they don’t work for anything that absorbs water, like wood or foam, but if you want quick and efficient industrial-strength cutter for bulk projects, waterjet is definitely the way to go.