Dotted lines being cut on CO2 laser

[ednisley]

@VixenDB

unable to recreate ANY dotting on either axis

I’m with @jkwilborn on this: that first burn doesn’t look right. It should be darker in the middle, not a ring around an unburned center.

The subject of laser resonance modes came up a while ago:

What is the cause for this? Help needed, problem since 5 Months now

A reasonably readable version: Full-frontal tech: The illustrations in those references show that TEM00 mode is a simple Gaussian hump in all directions around the beam axis. The laser can operate in other TEM modes that distribute energy in different patterns, none of which are useful for laser cutting. The mode is an inherent property of the tube / gases / mirrors, so external tweaks do not affect it. The machine’s alignment and focus can be perfect and the laser will still not cut pro…

The pix show other failing tubes; yours looks like a candidate to become a wall hanging.

Good use of a bad tube

I had this laying around gas nipple was broken in shipping and didn’t want to trash it. So removed both end mirror’s and fished some led lights through it. Now just to hang it up. [laser tube]