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Ed Nisley's Blog: Shop notes, electronics, firmware, machinery, 3D printing, laser cuttery, and curiosities. Contents: 100% human thinking, 0% AI slop.

Laser Test Paper Beam Alignment Targets

Having failed at making flexible plant tags, I figured using laser test paper to make laser test targets might work:

Test paper - target patterns - 2024-07-03
Test paper – target patterns – 2024-07-03

They descend from my original dot-mode laser beam targets:

OMTech 60W laser - beam alignment - 2022-03-22
OMTech 60W laser – beam alignment – 2022-03-22

The dots just barely punch through the back side (open in a new tab & zoom for more dots):

Test paper - target patterns back side- 2024-07-03
Test paper – target patterns back side- 2024-07-03

The plastic coating chars and buckles with each pulse, but remains in place:

Test paper - 2 shot - uncleaned - 2024-07-03
Test paper – 2 shot – uncleaned – 2024-07-03

Wiping the surface removes the loose coating / ash / debris to expose the underlying charred paper core:

Test paper - 2 shot - wiped - 2024-07-03
Test paper – 2 shot – wiped – 2024-07-03

Those are two pulses marking the ends of each axis, so the machine remains well aligned after the fourth-quarter tweak.

A single pulse shows the beam has a nice round shape with well-defined edges:

Test paper - 1 shot - wiped - 2024-07-03
Test paper – 1 shot – wiped – 2024-07-03

In principle, the beam should be more intense toward the middle, but I suspect that’s beyond the paper’s ability to resolve the energy; the beam either burns through the coating or it doesn’t. In all those targets, the back surface of the paper remains undamaged.

Manila paper targets seem to have better energy resolution and take much less time to produce:

Beam Alignment - Mirror 2 detail - 2023-09-16
Beam Alignment – Mirror 2 detail – 2023-09-16

The black test paper will certainly come in handy for something, though.