CO2 Laser cutters are insanely cool, but there’s one problem. We cannot see infrared beam, so it’s always a guesswork where laser is actually will hit the work piece. Many laser cutters including SH-G350 come with a red laser pointer attached near head cone, but they are far from accurate. One that came with my machine annoyed me to the point that I disconnected it completely. It never points to where laser is cutting (mine was about an inch off to the side) and it can only be adjusted up or down. Spot gets larger or smaller depending on where your z-table is located. And to make things worse,there was something wrong with mine as it kept on overheating and fading.
So what is beam combiner and why would you want one?
As you can see from the illustration beam combiner is a special lens that only let’s certain wavelengths thru, and reflects all others. In our case Infrared laser beam passes thru it, while visible red laser reflects. By adjusting angle of the lens you can get both beams to travel same path. You can actually see where IR laser beam is going and where it will end up on the table!
No more guessing, where you cut will be. As added bonus this makes it insanely easy to align mirrors. You don’t have to burn pieces of paper anymore! But wait, there’s more 🙂 ZnSe lens will also focus red laser beam, so you can even see if focal distance to the object is ideal!