These parts are easy to print, but material choice is very important. Print them in PLA. Why? PLA behaves much better than most plastics when hit by a laser; especially avoid any chlorinated plastics, but also avoid ABS because the gas produced if it gets hit by the laser is pretty nasty. The color of the material also matters; enclosure parts need to be opaque to the laser light, and the jigs should be made of a color that minimizes scattering of the laser light.
Read my Instructable to understand how these 3D-printed parts are intended to be used; also read other materials so that you can understand the dangers and safely operate your laser. Avoid the temptation to try things first and read instructions after a serious problem has surfaced: I didn't even plug-in my laser's power supply until after I had built an enclosure for the unit.
These parts were all designed using OpenSCAD. I might post a Customizer version once I'm sure the design will not change for a while -- for example, I'm still looking at alternative methods to make the vent filtering more effective.