3D printer laser bracket, vent and eye protection tube

thingiverse

I read a great instructable by [Jakes Workshop] to turn a 3d printer into a laser engraver, and so I created a bracket for my 2.5 watt laser and Tronxy X3 that i bought from gearbest. I've read about laser safety and at least understand the attributes of the laser class system, so the intention was to take a class 4 laser and incorporate it into a class 1 laser system, but the machine as it works is a little short of that goal. What it does do with the adjustable vent and eye protection tube is reduces the need for laser eye protection (LEP) and reduces the smoke and smell. If the work surface is flat then vent tube can be placed almost on the surface of the work making any spectral reflections trapped, however this could be used incorrectly and it would not be eye safe. Always do your own research, don't trust me! Because even with the tube on i found that in some instances the laser will turn on when i did not want it to, such as when i switch the 3D printer on it flashes the laser a few times until i get my PC connected in repetier software. so how i use it is i keep the LEP on until the work is in place an i'm sure the laser will not go over the edge. The laser I used has an adjustable lens on it, so I set the focal distance to about 86mm, out form the stop about 1 turn, if your lens is adjusted differently then the tube maybe too long or too short. the process i used to create laser engraving files is following the jakes workshop instructions, and then simply load the file in the repetier software and click print, it runs the Gcode all from the PC. the laser is controlled with a TTL control board that is plugged directly into the 12v second fan plug on the melzi board. the fan on the vent tube is connected to the 12v power supply. The example item in my photos is transparent PLA, so it glows like a light show when the laser is on, the plastic diffuses the laser light so that it is not coherent, and so eye safe. the 40mm fan has fiberglass filter material stuffed up stream of it so that it has some filtering, but i also run it next to an externally vented hood. the 4mm holes can be tapped after printing with 10/32 threads, but something smaller would be OK too. I designed a hose adapter, but could not find a good hose for it.