Burn marks on my Laser Head lens

I noticed my Glowforge hasn’t been cutting everything entirely through lately in areas of my cuts.

I thought it needed a cleaning but than noticed several what look like to be burn marks on the laser head lens.

Anyone has this happen and any idea why?

You might be able to clean that off by dipping a Q tip in isopropyl alcohol and gently dabbing some on to the lens. Let it soak a bit then use your lens cleaning wipes to clean it off.
Worse case scenario you can order a new lens.


Why is because there was residue on the lens. Infrared is just light until it touches something - then it’s heat. If the energy isn’t transmitted it’s deposited. Enough film on the lens gives a surface to deposit the energy on and it will burn the lens.
That’s why the first rule of lasers is clean optics! That includes the windows and mirror.


Just in case:
Printer Head Lens – Glowforge Shop


The lens and other optics need to be cleaned regularly because smoke deposits on them when you cut/engrave. Since this reduces the efficiency and focus of the laser beam it doesn’t cut as well. The deposited smoke gets burnt on by the laser path like your lens shows.

Hopefully yours isn’t beyond cleaning at this point. But at least the lens is a fairly inexpensive part. You should clean all the other optics, including the lid camera, at the same time, they are likely schmutzy too and could have their own burnt bits.


Did not follow basic cleaning regimen.

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It happened because the lens was not cleaned well enough or often enough.

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Yes, as others have said, it’s vital to keep those things clean. Hopefully you can salvage that one.
BTW you may want to remove your phone number as this is a public forum.


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