Laser Cutting Acrylic

[aws04]

Could someone please help with setup for laser 10mm & 25mm
acrylic on a bystronic byspeed. We only need to cut the odd
small part.I have tried the 10mm with all different cut speeds (500mm/m to 3000mm/m) and to power settings
(100w to 2000w) focal 1/3 in the material , biggest nozzle I have 3mm with .5 to 1 bar nitrogen. But cut edge still a bit dull and a bit fosty for the first 3mm of cut edge,nozzle height 3-5mm (I don't have height foot for non metals).I have no idea of a starting point for the 25mm.
I know this machine really suits metals but is it possible
to get a really shinny smooth edge?

Thanks Steve

 

[msandoval]

If this is clear acrylic, all you need to do is drop the gas pressure to about 0.1 bar, slow the cut, and now you will see clear edges. Try to put the focus at half the material thickness, and go slow, about 20 inches per minute. Again, clear plexiglass, not lexan, or other type of plastic. Make sure the nozzle never rubs the material.

If you go too fast with low gas pressure, the plume (or flame )of the cut will trail and burn the back of your material.

Good luck.

 

[aws04]

Thanks for the advice,

I have done some tests on 8mm acrylic & get the best results
with 400-500mm per minute, 300-500w , 0.1 bar nitrogen,
3mm nozzle, 5mm cutting height, focal 1/3 to 1/2 in materail thickness. Edge is fairly free of styrations & quite shiny but the top 2-3mm of the cut face has a quite frosty finsh I tried a lot of changes with in wide range from the above settings but cannot get nice shiny edge from top to bottom. I not going to even mention how the 25mm thick looked! Any Help would be appreicated.

Thanks Steve

 

[msandoval]

Try 0.01 Gas Pressure, Focus at 1/2 material thickness or deeper. The speed should be fine. You may want to up the power to about 700 Watts.

Good Luck

 

[aws04]

The cnc control will not let me set the gas pressure bellow .1 bar, I tried drilling an old nozzle out to
4mm when cutting the 8mm last time to see if that was why the top edge of the cut was going frosty. I haven't looked in setup or config to see if this minimum pressure can be changed.

Steve