I’ve never run across a variable that would alter this.
I use more air assist than most here. I’m at 35psi to achieve 30lpm flow. @jkwilborn is considerably higher than me, but I can’t think of anybody else running quite that much. Maybe @ednisley ? Point being, I’m somewhat familiar with the effects of (perhaps) excessive airflow .
I secure every single workpiece and often need to use tabs to keep smaller cutouts from dropping partially into the void and leaving a point standing up that can snag the laser nozzle or focus probe. I also use reduced flow on some jobs.
Between those three things, you should be able to get going nicely.
I’m running 60+ psi and I also secure some things but I make jewellery and currently working with 8-12mm Tassie oak with other timber veneer glued on
I currently create a new layer with 0% power and no air assist and this allows the laser to get into position and lower the z axis before starting air assist
It works but it’s a pain in remembering to put the first layer on the new cut path
I just thought some gcode could be added to when the z offset is starting, that would work for me
Also…if my psi is too high I would love to know the recommended pressure for the type of cuts I’m doing. I bring it down when doing long cuts but most are simple shapes
At 60+, you’re basically blazing a trail of your own. Jack might have some data to share. I can’t really exceed 35 without modification to my laser module. 30lpm was my somewhat arbitrary target (based on some numbers from OPT laser) and I got there. I can’t say if there’s benefit above that or not. Jack must think so… The changes I witnessed going from 9lpm to 30lpm were relatively subtle, but enough that I consider it worth keeping in place.
I got a small speed bump, wider kerf but a bit more depth, too, and the edges are MUCH cleaner.
Regarding the phantom layer, I think you could use sublayers with the parent layer set to no air and 0 power. Save that into the material library and it would be a simple matter to assign that setting to the job.
Edit: No…nevermind. That would still run the whole job. …
Indeed! The piddly pump in my OMTech pushes a dozen-ish liter/min through all that tubing, which suffices for my simple needs.
My flowmeter tops out at 20 l/min from an (extrapolated) 15 psi just upstream of the assist air valves, so I couldn’t check the higher pressures you folks use.
I sympathize with @unstable81, The laser cooling fan downdraft creates a problem sometimes, and nozzle air is worse. On the upside, it also pushes warped ply into the correct focal point when using 100mm x 150mm 1.8mm ply.