Air assist is basically ‘injecting’ air into the cut to accelerate the burn by providing more air, and ejecting smoke and debris out of the way. 4mm is pushing it for a 3.5w, but it might be possible with multiple passes and air assist. An inflation needle with an air pump connected, pointed directly at the spot your laser hits would work as an air assist. Whether it would be enough, I can’t say.
Air assist also prevents fire, because it’s blowing out the flame.
An Emblaser 2, with a 5w diode and built in air assist, takes 2 passes at 100% power, 3.3mm/sec. You might need 3 or 4 passes with a lower power machine.
… I have an adapter which allows me to connect a hoover to the z axis to remove sawdust when cutting with the CNC spindle.
If I used this with the laser it would sick the smoke and debris away and also suck air into the hoover pipe, I’m wondering if this would be like ‘reverse’ air assist in that air would be being pulled across the Lasered area instead of being blown across it.
I have tried many times to cut through 3mm plywood with poor result, up to 20 turns with max power and very slow speed when you are finally through, the subject is very burnt at the edges and there is a lot of grinding afterwards. However, there are very fine and expensive plywood on the market, which gives somewhat better results.
(it was a 5.5W Eleksmaker diode laser I used, I have no idea if an Emblaser2 is that much better)
It is a really nice and good looking diode laser machine with a real 5 watt laser diode and lots of accessories, but it costs more than a Chinese 80 or 100 Watt Co2 laser machine with all the accessories you need.
Emblaser2 is probably mostly intended for schools and public institutions, I think.
… No go on the 4mm, or more specifically ‘some go but way to slow’…
… I did 50mm/sec at 100% power and after 8 passes it had almost reached through, but it took 12 minutes to do those 8 passes on a 2cm square… Who has time for that…
… Will use the CNC for cutting and laser for engraving.
… you want to buy a larger machine because it is so satisfying to see the laser cut through thick material without everything, including your fingers becoming black of soot, and you mostly have no finishing of the items afterwards.
Not sure how it’d translate but I’ve cut¼" plywood @2ipms with 100% with a jtech super 7w diode so could assume half the wattage would triple the time and reduce chances of success. The problem with plywood though is it’s densities vary greatly. Your better off trying to cut solid hardwood sheets like basswood alder or cherry I can cut these ¹/¹⁶" and ⅛" @6 to 8ipms and full power very well without air assist.