Scalable Laser 2.x - Gantry, Frame, Skins and Drive Mods

I'm really excited about Barton Dring's Buildlog.net Laser 2.x design, but I need the available cutting area to be just a bit bigger. What parts need to change to get a larger (or smaller) cutting envelope? These parts.

Given the x-y-z dimensions of your desired cutting envelope, this OpenSCAD script calculates the length of all the MakerSlide and other aluminum extrusions for the motion system and frame, as well as belt, drive shaft and leadscrew lengths. It also renders new skin panels to f