Some items cut all the way through, and some don't

[jbv]

It would help to know what material you are using.
Level matters, but the material being flat really matters. These hold-down pins are indispensable:

Honeycomb bed holdown pins

the best laser results are achieved with flat (non warping materials) in order to maintain consistent focus. Also, when cutting light materials like paper, the exhaust turbulence can kick up the material and ruin your job or at worst… catch fire. (speaking of which, I hope you all keep a small fire extinguisher in easy reach, near your machine - safety FIRST) I hope you find these useful. I used to 3d print them for my other laser cutter but occasionally , they would see the wrath of the laser …