That's just garden variety selective laser melting, nothing specific to Space-X. Though I've never heard of "shaking it up", the standard way to apply powder is to use a moving arm with a powder feed.
For a hobbyist, I'd expect these could be a problem:
* Lasers that can melt metal are expensive and dangerous.
* Optics for such high powers are also expensive.
* Atmosphere control is a must, you don't want oxygen near metal powder under a laser.
I think at this point it would be better to start your own company and earn money from it, it seems a bit much for a fun garage project.
EDIT: There was a hobbyist project for an electron beam 3d printer posted to HN some time ago, maybe that would be more achievable (at least the beam shuts down itself if air enters the working area. The potential for implosion seems nasty though).
For a hobbyist, I'd expect these could be a problem:
* Lasers that can melt metal are expensive and dangerous.
* Optics for such high powers are also expensive.
* Atmosphere control is a must, you don't want oxygen near metal powder under a laser.
I think at this point it would be better to start your own company and earn money from it, it seems a bit much for a fun garage project.
EDIT: There was a hobbyist project for an electron beam 3d printer posted to HN some time ago, maybe that would be more achievable (at least the beam shuts down itself if air enters the working area. The potential for implosion seems nasty though).