A laser engraving machine will engrave, etch, or mark most materials but depending on the power of the CO2 laser tube it can be a powerful cutting tool as well. And unlike any cutting tool I know of you don’t have to secure or lock down the material that’s being cut since the laser beam never actually touches the material surface.
Even low power CO2 systems can slice up a variety of materials, like:
- Vinyl masks, overlays
These represent potential new profit centers to many laser owners. Being able to cut materials means an engraving business can now produce marketable items such as:
- Name tags
- Vinyl / acrylic lettering
- Cutouts from balsa woods
- Architectural models
- Christmas ornaments
- even craft items!
A 30 Watt laser can generally cut materials up to 1/8″ thick. Higher power systems will be able to cut thicker materials more quickly. When choosing a laser engraving machine, keep in mind that cutting will take much longer than engraving. With lower powered laser machines you may need multiple passes, as well.
If you anticipate offering both cutting and laser engraving as a service on an ongoing basis, you’ll definitely need a much more powerful laser tube for faster and longer cutting engraving speeds. Time, after all, is money.
“For most engraving you can get by with a 40 watt laser engraver. However, for cutting look at a 50 or 60W at the absolute minimum.”
Some materials do cut poorly with a CO2 laser. Metals and glass are among the materials you should not try to cut. If you plan to cut those as part of your business, you’ll want a separate Nd:YAG based laser system.
If you only plan to work with those materials occasionally, you can look into custom laser engraving services. By outsourcing parts of jobs that aren’t a core part of your business, you can avoid the up front capital costs, though you’ll pay much more per piece.
Conversely, if buying a metal cutting system is an option, consider offering custom laser engraving to other operators. This can provide you a new source of revenue and give you access to new markets.
Using a Laser Engraving Machine for Cutting
It’s fairly simple to turn a laser engraving machine into a laser cutter.
Start by making sure the machine is in vector mode, not raster. The difference is critical for cutting. Vector mode draws continuous straight lines, like cuts. Raster moves the laser back and forth, firing at points where the image should be, to build up the image out of a matrix of dots.
Many systems will switch back and forth between vector and raster automatically depending on the line thickness. Check your manual to be sure.
Just as in engraving, lay out the artwork in the graphics program. If your graphics program doesn’t have outline capabilities, it won’t work for cutting.
If the source artwork is a TIFF format image, it may have to be converted to HPGL. Always use the thinnest lines possible for cutting.
Keep PPI above 150 for cutting. Below 150 pulses per inch means that the points will be spread out so far that they don’t touch. This will not produce a continuous and clean cut. On the other hand, that may be just what you want when making perforations in paper or rubber stamps.
Set both power and speed just like with engraving work. You’ll probably find that the speed has to be lower so the beam can cut through the material completely. What laser power to use will depend on the material and the result you want.
It’s worth noting that some materials cut more cleanly if you mask or dampen one or both of the sides. Your laser manual will have recommendations from the manufacturer as to speeds and feeds. A bit of experimentation will let you fine tune these for optimal results. Just make sure to save them for future jobs, in order to save time.
(If you’re using laserable materials, the manufacturer may have recommendations, so check with them as well.)
You can make many products in one step using a combination of raster and vector modes. Your machine may have a color mapping function that allows you to indicate which one should be used. When using both modes, the machine will generally do the raster engraving first. At the end, it will vector cut the designated shapes.
The combination of both vector cutting and raster engraving makes manufacturing name tags, signs, and keyfobs fast and very easy.
Laser Cutting Aids
To get clean and undistorted results, there are a few accessories available that will help. Most take the form of specialized tables. By keeping the material off the machine’s table, you prevent beam reflection and considerably improve air flow.
Beam reflection happens when the laser beam travels through the material and reflects off the metal underneath. It can then proceed to mark the underside edge of the material, which may ruin it. This becomes particularly important when both sides of the material will be visible to the user, as with key chains.
Proper air flow is critical regardless of how the final product will be used. Good airflow makes a much cleaner and more precise edge. It even reduces burning around the cutting path. Proper airflow does this by sweeping away heat, smoke, and debris before they can damage the material.
Air assists are a common way of improving cutting quality. Air assists can also improve the effective laser power. An air assist blows a fine stream of air across the surface being engraved, keeping debris, smoke, and fumes away from where the laser’s being focused onto the material.
It’s possible to make your own laser cutting tables. The following materials allow good air flow and prevent unwanted reflections, especially if you spray-paint them flat black.
- Fluorescent light “egg crate” diffuser panels
- Paper honeycomb treated with fire retardant (untreated paper may cause a fire)
- Aluminum or stainless steel honeycomb (a common material for commercial laser cutting tables)
- Fine metal screening
Air flow enhancing surfaces like these are often combined with downside exhaust supporting tables. Those kinds of tables pull smoke, vaporized material, and fumes away from the cutting point. This minimizes smoke damage, and produces much more consistent laser power. By removing smoke from the underside, much less laser power is absorbed by smoke and debris rising from the material. The result is a more consistent cut, with less finishing clean-up necessary.
Downside exhaust tables generally mount on top of the engraver table, and usually come with their own datum stops or rulers. Your laser manufacturer or dealer will be able to recommend one for your laser.
Vacuum work support tables are another option. These tables are generally aluminum, drilled with many small holes. The vacuum suction holds the material flat. Vacuum support tables are great for cutting flexible materials that might otherwise bow or warp during processing, like:
- Flexible brass
- Engravers’ plastic
The perfect flatness achieved by a vacuum hold-down table will give you much better quality and consistency. The ease of positioning materials — no more lead weights! — will also save a lot of time.
When cutting a lot of material, exhaust is inevitably an issue. This is particularly true when cutting acrylics or plastics. Some laser units, like larger ones, may have specific requirements for the exhaust that they need in order to function. You will have to have a certain air exhaust volume and pressure available at the time of installation.
For cutting the polymer mat material needed to make rubber stamps, look into a charcoal filter, sprayer, or bubbler exhaust air cleaning system. These can help eliminate potentially hazardous fumes. Check with the air filter company for their recommendations.
Rotary System Attachments
Most higher end laser engraver systems offer rotary attachments as accessories, These allow you to engrave cylindrical objects like drink glasses. Rotary attachments are generally available either as roller or chuck types, each with their own trade-offs. The maximum diameter you can engrave will be limited by the Z-axis travel your laser system allows.
Where to find a laser cutter for sale
Yes, cutting takes a little more thought than laser engraving. On the other hand, the tremendous possibilities opened up by maximizing your engraver as a laser cutter neatly illustrate the incredible versatility of your laser engraving machine. Among other retailers you can find laser cutters at a reasonable price at Boss Laser. I’ve got a lot of respect to the quality of parts they deliver. They’re not the only laser machine supplier out there of course, but my experience relative to a few others makes these guys tough to beat.