The OMTech laser arrived with a 120 VAC fan blowing air out of the electronics bay on the right side of the cabinet. It runs continuously, because the stepper drivers remain active even when idle, and gave off an annoyingly high-pitched whirrrrr.
The Big Box o’ Fans produced a 24 V tangential blower which (felt like it) moved about the same amount of air with a quieter and lower-pitched hmmmmmm, so I made an adapter to fit it into the original cabinet opening:
Yeah, it’s hot-melt glued to a stacked pair of laser-cut cardboard plates. Fight me.
The white square of retro-reflective tape came from its previous life as a test item.
The black cardboard makes it rather low-key from the outside:
I reused the original grille, mostly because otherwise I’d have to put it somewhere else.
The anemometer suggests 5 m/s airflow an inch from the grille. Rounding downward from the 25×35 mm opening says it’s pulling 9 CFM from a compartment with a little over a cubic foot of free volume, which sounds enough good to me. For whatever it’s worth, this airflow calculation disagrees with all of the specs and my handwaving calculation in that old blog post.
The cabinet hatch has slits distributing the incoming air over all the active ingredients (somewhat visible inside behind the flash glare):
The SVG image as a GitHub Gist: