The suitability of a Fiber Laser Galvo Engraver for Cutting

A topic that sometimes pops up is the suitability of a fiber laser galvo engraver for cutting. Since the point seems to be rather over-stressed by those who feel the need to do so, I figured I’d contribute my $0.02. I don’t want newcomers seeing comments about how engravers are only suitable for engraving, and getting the idea that they can’t do cutting at all. If I’d seen that when I was starting out, I’d have been very discouraged. — Lindsay Wilson.

Fiber laser galvo engravers are what I’d imagine most people will be using. These are typically below 100W in power, with a galvo scanning head to move the beam, and are desktop machines. Proper fiber laser cutters are typically above 1000W, use an XY gantry system to move the cutting head, and are generally huge floor-standing machines.

Is it technically possible for a fiber laser galvo engraver to cut material? Yes, absolutely, no problem at all. I have a 60W JPT M7 with a 112x112mm lens, and regularly cut 1.5mm silver. The thickest I’ve ever done is 3mm copper, although that was pushing it a bit. It is NOT fast – for example, the effective cutting speed I can get in 1.5mm silver is about 7mm per minute. (Note – that isn’t the scanning speed, that’s the speed it will cut an actual shape, once you set up the hatch offset, pen settings etc.). A typical small pendant might take 15min or so. Additionally, the cut edge has a taper of around 10-20° – this is just a result of how the laser cuts and is not affected (significantly) by lens choice.

An actual fiber laser cutter will achieve cut speeds much faster – I don’t know exact figures offhand, but it would be in meters per minute, not millimeters! It will also have hardly any edge taper, because the laser blasts right through in one pass, rather than taking a little bit at a time and several hundred passes like with the galvo engraver. However, a fiber laser cutter is incapable of doing engraving – it’s simply not the right laser for that purpose. This is where the galvo engraver excels – it can both engrave a design, and cut out the part as well.

Is it economically viable to use a fiber laser galvo engraver to cut material? This is more important, and it depends on exactly what you’re making. If it’s a small, high-value item like jewellery, then absolutely it’s economically viable. If it takes 15-20min to engrave and cut out a silver pendant which sells for £100, that’s a winner. The first laser I got (a 30W) basically paid for itself in a couple of months by doing jewellery (we already have an established jewellery business, so it was an add-on for that – don’t expect to get a machine and suddenly start making money!). If, however, you’re trying to do lower value things like cutting keychains or dogtags, it’s definitely not financially viable. Something like that is indeed far better cut on a big cutter (ideally, by someone else!) and you can then focus on doing the engraving instead.

Here’s a few random examples of jewellery that I’ve done, both engraved and cut on the 60W laser. They’re all about 20mm in size, done in 1.5mm fine silver (I think Nessie was 2mm).
Bottom line, it all depends exactly what product you’re making.