Strange double line due to misaligned mirror

2 years ago by pmk to c/lasercutting

Turns out a misaligned mirror made the laser hit the lens in a weird way, and then bouncing off something on the way out to produce this double line. Probably. What kind of strange troubleshooting have you done and what was the reason/fix?

HaywardT 2 points 2 years ago

To me this looks like it could be due to backlash. Did both lines appear at the same time, or are they from two different passes.

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path: 0 10014894, hotness: undefined, score: 2, children: 2

pmk 1 point 2 years ago

One pass. What does backlash mean? (I'm kind of new to this) Aligning the mirrors did stop it from happening again, but maybe that was accidental?

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path: 0 10014894 10014932, hotness: undefined, score: 1, children: 1

HaywardT 2 points 2 years ago

Backlash is the play in the gear train. It would be evident if the cut was made one direction then the other. Seems like you had a different problem. Never seen that before.

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path: 0 10014894 10014932 10014967, hotness: undefined, score: 2, children: 0

glimse 2 points 2 years ago

Is the glass separating from the mirror layer or something? I've never seen anything like this but it reminds me of the double reflections you get from mirrors with thick glass.

Or maybe it's so misaligned, the laser is hitting the edge of the mirror...?

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path: 0 10018110, hotness: undefined, score: 2, children: 9

pmk 1 point 2 years ago

The mirrors seem fine. I don't really understand it but aligning the mirrors made it go away.

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path: 0 10018110 10021288, hotness: undefined, score: 1, children: 8

glimse 2 points 2 years ago

Could it be hitting the nozzle? That would be a very minor misalignment so it might be hard to notice

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path: 0 10018110 10021288 10021748, hotness: undefined, score: 2, children: 7

pmk 1 point 2 years ago

Could be. Is there an easy way to test that? For the mirrors we had pieces of paper to see where the laser hit.

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path: 0 10018110 10021288 10021748 10023153, hotness: undefined, score: 1, children: 6

glimse 2 points 2 years ago

Can you take the nozzle off for a quick test? Mine unscrews for cleaning, not sure if they all do though

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path: 0 10018110 10021288 10021748 10023153 10027476, hotness: undefined, score: 2, children: 5