Nozzle Cone Size

[Shannon Chappell]

Hello, I have two nozzle cones that came with my laser cutter. One has a 2mm opening and the other has a 6mm opening. I was wondering in what situations I would use each different nozzle cone. I read, for instance, to use the 6mm cone when working with acrylic, but I do not use air when cutting and engraving acrylic... any tips or info would be appreciated.

[Dave Sheldrake]

They are for different focal length lens's

The one with the bigger hole is for a longer focal length lens

[Joseph Shawa]

You might notice using a longer focal length lens that the cone is warm or hot to the touch after use because the beam hasn't come together enough when it exits. I have and extra cone that I cut wide open but still have it hooked up to air so as to keep the lens clean.