Fiber laser cutter

I had a few projects that would benefit from being able to cut metal sheets. For example, the mask in the focus schlieren system, or a grid in the triode build. So I purchased a 20W pulsed fiber laser source.

Getting to the first cut

The first prototype (in the top image) was a quick test with some laser cut parts and a surface first mirror and a lens I got from Thorlabs. All of that was mounted to an old 3D printer frame. But this version didn't last long as the mirror soon shattered.

I machined up a new nozzle with air flow and a 45deg mount for a dielectric mirror. And mounted it all to the same 3D printer frame. This got a stable enough to get some cuts in. With enough passes I was able to cut shapes out of a 0.4mm thick brass sheet.

Galvo

I also wanted to be able to raster a rather large area. One example use case is direct to mask for etching PCB; by covering the copper with say spray paint, then removing the paint in the areas to be etch with the laser rastering. To do this, I wanted a faster scan speed than what the 3D printer frame can do. So I bought a galvo and attached it.