When you have aligned your lasers beampath to perfection, you now need to be sure the beam is 100% vertical to make a straight cut through the material.
Here you have a simple tool to make this alignment.
-First make sure you hit the nozzle in the middle by adjusting your mirrors.
(for this I use a homemade gauge with some painters tape)
-Put a piece of painters tape under the cone.
-Place the cone directly under the nozzle and raise the table until the cone centers gently on the tip.
-Fire a short pulse.
-Now it's easy to see if the spot is in center using the aiming lines under the cone.
If not, you need to move the cutting head a little bit, and then try again until you hit dead center.
(Remember to check and adjust also at the nozzle every time you move the head)