David, I've seen people using a shop vac or small dust collector at shows or at Woodcraft. You just want to clear the smoke so that the lens isn't coated with particles. Carbon dioxide lasers work in the far infrared, so normal optics don't work. The lens is an orange color and is made from stuff called zinc selenide. You don't want to buy a bunch of those. They get expensive.
The laser was self taught. They should have a book with instructions. Normal X-Y plotting is very simple; it can work with raster graphics like a photo, or with vector graphics, like a CAD drawing. In raster mode, the laser scans back and forth adding lots of small dots like a dot matrix printer. In vector mode, it follows the lines drawn. Vector mode takes less power. On mine, you can dictate the power by the color in a CAD drawing. There might be 16 customizable (maybe more) power settings. You can equate red lines to 85% power, 63% speed, and 400 dots per inch, for example. The DPI can go way down to something like 50 for things like serrations in notebook paper to 1000 DPI for extremely detailed engraving. Most woods and things that burn more easily get something like 300 DPI to keep it from igniting. Dialing in the proper speeds and feeds takes some experimentation. They will give you good guidelines to start from.
The laser is driven from a program like Corel Draw or AutoCAD. It is essentially thought of as a plotter, and the plotter configuration is where you make the changes for power setting and things like that.
A rotary axis is a little more tricky. On mine, you input the diameter of an object and it will scale the drawing you have to wrap around the part. You need to be pretty precise with your measurements if designs are to come around and meet. This is why I use CAD to drive mine. I get very good plot control this way. When burning a simple one time thing, I'll first burn the design onto a piece of cardboard taped to the floor and go back and position the real object where the engraved outline was. This allows for dead nuts positioning without wasting expensive parts.
I'm about to work on a very tough laser project. It will draw a continuous design around a curving pen body. This will mean that my graphics will have to be scaled in several slices to relate to the correct diameter of the pen for any given X dimension. It should be a challenge.[
]
].