How do I regularly cleanse the galvo mirrors easily and safely?


Through the open mirror system, dust and resin vapors continuously settled on the mirrors.

Already in the delivery state of Moai 200, the mirrors and the environment were so dirty:

The fouling of the mirrors over time leads to an ever increasing scattering of the laser beam, which leads to a reduction of the laser power and to a lower resolution during the resin exposure. Therefore, the two mirrors should always be clean.

:exclamation: When cleaning the mirror surfaces, you have to be very careful :exclamation:

The following should be noted during the cleaning:

  1. The mechanical pressure on the mirrors must be minimal
  2. The cleaning body (foam swabs) used must be free of lint, dust and finger grease, as well as solvent-resistant
  3. The solvent used must be volatile and evaporate without residue
  4. The solvent must not attack the mirror surface or the mirror kit

I recommend the following solvent (LOCTITE 7063) and foam swabs:


It is best to soak a fresh sponge and shake it off briefly, so that not too much solvent in the sponge is (not dripping wet!) And then moves with ultra-light pressure over the mirror and thus removes the stubborn dirt.

Repeat this until the mirror surface appears clean.

The finish is always done with a virgin sponge rod that is used only once and pulled over the mirror!

Helpful in the assessment of the purge action is an LED flashlight with which one side (obliquely) illuminates the mirror surface. This makes deposits, such as particles and veils, very visible.

The degree of soiling should be checked regularly, as the lower area of ​​the printer is not hermetically sealed and air convection distributes dust and resin vapor evenly on the mirrors.

The use of compressed Air Duster Spray can remove slight dust deposits on the mirrors, but also stir up dust from the environment, which then settles on the mirrors!


Need help printing the calibration file
Galvanometer housing

I am not yet the owner of a Moai (soon, I hope), but going around the forum for infos, I saw this post and I though about giving what advice I could, as a everyday user of lasers and optics (in research), to complement the above post (which is already very nice).
First, I can only insist on the points given by @ad_fontec :
-Never exert force on your mirror’s surfaces!
-Always use “extra clean” materials: lint-free wipes, wear gloves or make sure not to to the wipe area that will be used with your fingers, use high purity solvents (not from your hardware store).

With our lab mirrors (that are very fragile and sometime cost more than a Moai), we of course need to clean our optics on a regular basis, with extra care (most of the time, mirros do not have any protective coatings on them). Not having the Moai’s mirrors in front of me, I cannot say whether or not this is relevant here, but here is the standard procedure to clean such mirrors from dust:
-grab a tissue (such as ), with twizzers or whit gloves.
-place it sligthly over the surface to clean: the tissue should “hover” over the mirror, without really touching it.,
-grab your dropper (with clean solvent in it, acetone, methanol or ethanol would do), and get one drop on the tissue: this should get it to stick to the mirror surface by wetting everything.
-now lightly pull on the tissue: puling to the side will wipe the mirror, without pressing on it’s surface at all.

Here is a poorly ( I am definitely not a graphist ) drawn scheme of this, as I am not sure my words are very clear:

I would suggest to go to the other cleaning method only if the traces are more resilient than a bit of dust (fingerprint, for example).

best regards, and happy printing!



Thank you Thomas for the professional guidance!

Unfortunately, the galvo mirrors are difficult to access and there is no technical information on the mirror surface and putty. Thus, the selection of a suitable solvent is difficult (trial and error) :neutral_face:



This seems to be a common enough issue that we should probably look into designing a good dust cover for the galvos. It already comes with a good piece of glass for the top, but the sides remain wide open. I’ll have a look, I bet it wouldn’t be too hard to design a box with a slot for the provided glass to sit over top of everything and reduce the cleaning frequency at the very least!



Hello Dan,

with the enclosure of the galvos you place your finger on an open wound of the moai.

The open mirrors have long been a thorn in my side. Only a few days ago I completed this solution on the fly: Galvanometer housing

If you encapsulate only the galvos, then it is easier. However, the laser and the galvos should not get too warm!

However, a thin aluminum sheet metal case with a fan outside that “cools” the case and even the drivers, could work.