It is really important to use proper lubricant. From my experience, I would not recommend to use Grease because debris easily get attached to the grease and will increase friction. This will results in fast wear and tear in the Linear Guide and Rail of the laser cut machine.
The most suitable lubricant is less viscosity oil such as WD40 or Motorcycle Engine oil or Car Engine Oil. I would recommend to clean the laser cut rail once a week.
This chemical is one of the cheapest and best to remove dirt on mirror and lens. I would not use thinner because it will remove coating on the lens and thus effect the laser cutting and engraving. I would recommend to clean the mirrors and lens once a week. I have a friend that use his saliva to clean the mirror and for me it is not properly cleaned(not recommended)
Laser Tube operate efficiently at low temperature. The lower the temperature the better the performance. However, low temperature of water will results in water condensed at the tube and the whole piping sytem. In my country, the lowest water temperature that we can set without any water condensed at the pipe is 24 Degree Celcius. I would recommend to change the water twice a year.
Air assist will help to reduce temperature on the laser head. If air assist is switched off, the head of the laser will increase in temperature and may damage the lens. Besides that, without air assist will results in increase fire hazard risk.Air assist also avoid smoke and dirt build up during laser operation. Clean the air filter every once a week.
Lesson learned the hard way. For the past 5 months I forget to clean the Air Filter . My electricity bill shoot up a little bit because the Electric fan and the Chiller work harder to reduce the water temperature. My suggestion is to clean the Air Filter on Monthly basis. This will reduce your electricity bill.