3D Model Maker (CNC)
I don' t have the technical or computer skills to make this happen, but I'll bet someone out there does. I've heard of and read about these polymer 3d model makers and I understand that a few colleges have them. I know that one in my area does, as it was reported in the local newspaper. I also understand that they are quite expensive.
I've seen the Instructables for some 2D routing tables, and even a couple for 3D work, using a hot glue gun or some other flexible material for building the model. Crude results, comparatively speaking, but impressive from the standpoint of the home hobbyist.
I've recently learned of a product called Solarez, which is a UV curing resin for fiberglass work. No limits on the working time of the resin, no gelling up in the middle of a job, it seems like a dream for complex fiberglass projects. Put it in the sun and three minutes later, it's fully cured. There are videos on YouTube for the fiberglassing aspect of things. They are not as exciting as the Instructables, but they are instructional. I plan to use Solarez in my future fiberglass projects, but I have a quart of very expensive epoxy resin to use up first.
I figure if you fill an aquarium with Solarez and put a Z-axis table at the bottom, and a 2D UV laser on the top, you've got exactly the same thing for which others are paying thousands of dollars.
I don't know how strong the Solarez would be in a stand-alone construction and I doubt that the manufacturer of Solarez intended it to be used in this manner, nor do I know how the stuff would react to a UV laser, and if it is practical from an elapsed time frame of reference.
Again, I don't have the tech skills, nor even the need for such a device, but I think it's within the skill set of some of the more talented Instructable builders here.
Just some random thoughts...