I watched this Genius of 3D Printed Rockets video the other day. They are using plasma discharge heating, but it is not very well controlled at all. They say “it works really precisely”, but it throws off heat and light and bits of wire, and fluctuates a lot. It only needs to melt the aluminum wire so that it flows and bonds properly, and maintain the environment of the deposition to assure proper cooling and crystallization.
They do little monitoring at a micro-scale, and don’t seem to be using more than one wire feed. No mention of ribbons, meshes, composites, chemistry, cooling, pressures, or metallurgy at all. Maybe it was just a fluff piece to raise stock prices, but it seemed rather sad to me. It is so trivial to solve for the controls – constraining it to be quiet, stable, efficient and fast. It is really none of those, and what is sad, is they don’t even seem to have tried. They are right about the economics of replacing whole engine components with 3D printed parts. But then they did not apply a design philosophy to the whole rockets, particularly to quiet, stable, efficient combustion of high energy density fuels. The technology is decades old, their groups are still stove-piped and not working as a whole.
Next time you make a cutting video, add scales, temperatures and conditions. It looks really “science-y” (joking), but it also is what you need to model and simulate and simplify in the modeling phase, not by processing tons of materials.
I did not realize you had these skills and interests. Or you told me and I forgot. If you need anything, just ask. I want you to be successful – to create new things that change the world and how we see it.
Richard Collins, Director, The Internet Foundation