Phil Reeves, the vice president of strategic consulting for Stratasys, a leading maker of many kinds of additive manufacturing machines and materials, says many widely used plastics may not be compatible with the process, since it relies on combining the powder with an additional, light-absorbing material.

Hopkinson has said in the past the HSS is best suited to thermoplastics, from elastomers to engineering polymers, but in the long term it could apply to metals and/or ceramics.

He now says the machine his group is building will be able to deliver additional materials, such as conductive inks used to print electronic devices, which remains a big technical challenge for additive manufacturing.

Meanwhile, HP announced last October that it was developing somewhat similar technology. Though details are murky, HP calls the technology Multi Jet Fusion. It appears to also employ an ink-jet print head that can deliver both a radiation-absorbing material and another material it calls a "detailing agent."

At the time, HP said its technology would operate at least 10 times faster than existing 3D printing systems. The new machine, expected to be released in late 2016, is also said to be able to digitally print items in different colors and manipulate their form, texture, strength, elasticity, friction, as well control their electrical and thermal properties.

Unlike elective laser sintering, which prints objects point by point, HP's printer will use fused deposition modeling (which lays down plastic in toothpaste-like layers), and be able to prints whole layers at a time.

HP said then that making 1,000 gears using its new printer would take 3 hours, while using laser sintering would take 38 hours to do the same job.

While both the HP and this new approach have yet to be proven in the market, it does seem that we may be close to a "tipping point" in 3D printing that could allow it to go truly mainstream for a much broader range of items and parts to be economically produced.

As many observers have noted, 3D printing is a digital technology and thus subject to Moore's Law, meaning capabilities will double for the same cost about every 18 months.

Are we truly near a tipping point for 3D printing in terms of what can be made and at what cost in scale? Let us know your thoughts at the Feedback section below.