Electron beam cutter

Work exists on creating a 3D printer using electron beam melting to create 3D objects. The electron beam might be useful for cutting instead of a laser beam.

--The electron gun can be fabricated without needing to mix the gases for a tube(even a CO2 laser uses a host of other gases, some hard to get), making it potentially easier to use

--the needed vacuum does not need to enclose the entire work area. A beam can get through a fair amount of air without dissipating, and open end vacuum tube designs exist.

--Due to the absorption spectrum, an electron beam is more efficient at cutting metal than the cheaper CO2 lasers.

--the gun design would also likely be used in a RepRap Metalica type printer, giving part commonality.

There are concerns with an electron beam though:

--Power levels shown for electron beams seem to be higher than those for lasers for similar purposes, but efficiency in beam creation might make up for this.

--When cutting materials with heavier atomic weights, X-rays can be produced. Precautions for working with X-rays would have to be observed.

--Cutting materials like plastic and wood make smoke, and this might cause more trouble for an electron beam than a laser.

--While electron beams have been used for a while in metal fabrication and a host of institutional knowledge exists, a brief Google search doesn't see anything on plastics or wood being cut, so this area would be new territory.

references: electron beam melting electron beam variants laser cutter