(Long time no see, again! Everythings fine around here, will explain at some point)
If you look for air assist nozzles in google, many of the examples that show, look like this:
Even like this:
Because all those diagrams, one could think that doing an air assist is easy, just put some narrow tube and inject air. HOWEVER, that might be good for industrial lasers with fancy air compresors that deliver cleaner air than an operating room.
For us mortals, we usually don’t have the luxury of such niceties, so our compressors will deliver condensation, oil or dust into the airstream, wich leads to crusty lenses:
Residues burnt into the walls of the air assist, hole in the right is the air inlet.
Not long ago I realized that, and gave it a thought for a while, until I decided upon a machined a sleeve to protect the lens from the airstream. It had to be long enough so that the turbulence generated at it’s end, should not get up into the lens. Ideally, the venturi effect should give a reduced pressure in that area, making for a cleaner laser path.:
Also changed lenses (bought a fancy Lightobject 18mm F50 lens, but didn’t want to use it until I had made this mod.
Lets see how everything fares with this!