For those of you with lasers, what settings are you using to cut Delrin. We are running a 100W tube, at 90% power and 8 mm/s to cut 1/8" thick black Delrin sheet. Holes come out nice, but when contouring for just a few inches, it set the whole thing on fire, to where the Delrin continued to combust and melt itself after being removed from the laser, thus scrapping the part. How do you keep it from catching fire itself?
We haven’t cut too much delrin on our laser yet but I we have done some 1/4" white delrin with no problem settings were somewhere around 75% of 100w and 4-5mm/s from memory.
How is your air assist on the machine?
Only Delrin fire and near-fires I’ve had were on very thin material, with parts packed closely together, like cranking out an entire sheet of 1/16" thick spacers. Forget the exact speed/power settings as it wasn’t my laser, but it was a 60W with no air assist at the lens, just aggressive active ventilation. Geometric spacing, and giving the heat some room to dissipate, has more of an impact than exact settings in my experience.
Sure you know this, but a general point of caution to people reading this thread for technical information: Delrin fire, much like an alcohol fire, is blue/mostly invisible. Be careful and pay attention.