Dust and condensed resin vapors that settle continuously on the mirrors are relatively easy to remove (see How do I regularly cleanse the galvo mirrors easily and safely?).
But what to do if resin drips on a mirror? If you do not remove it immediately with a solvent, it immediately hardens by the laser. Whether you can remove the hard resin without irreparably damaging the mirror and galvo, I dare to doubt.
Well, the known acrylic plate may protect the mirrors from resin drops and also a little dust, if you remove the VAT or Moai unused stands there.
However, this plate also has disadvantages:
- Acrylic glass swallows about 10% of the UV laser light
- The acrylic glass surfaces reflect the laser beam
- The deflection of the laser is changed by the protective window (new calibration with window necessary)
In principle, an enclosure of the galvometer is the only sensible way. You just have to be careful that the heat does not build up on the galvos and the drivers. I solved it this way:
The galvos and the drivers are in a closed and blackened chamber made of foamed PVC.
The laser looks through an anti-reflective window (lens protection: B + W Clear 007 Filter XS-PRO Digital MRC nano 43 mm). The protective filter sits in a filter adapter and can be easily screwed in and out:
The heat I get out of the chamber with a convection cooler (2 Peltiers with fan and water cooling).
With a PID controller, I can set the temperature to +/- 0.1K:
At the current ambient temperature of 32 ° C, the two Peltiers in the chamber reach 25 ° C quickly and are kept stable.