Made a video about polypropylene laser cutting as I only found different opions on how you can cut polyproplene with a lower power, cheaper laser cutter like the K40.
Hope you find my results worthwhile and use it for your own projects.
Very interesting. I tried a couple of times but need to find a better material (abs?). Also need to try different pwm period using grbl-lpc $33
According to these people ABS tends to only melt and catch fire in the laser
http://atxhackerspace.org/wiki/Laser_Cutter_Materials
I have cut ABS with no problem. 11mA/10mms No fire and no melting.
missing/deleted image from Google+