Ask people how long 3D printing has been around, and most guess people 5 or 6 years. They are surprised to learn that key breakthroughs like additive manufacturing and stereolithography date from the early 1980s, and that the first 3D printed human bladder was implanted in 1999.
The truth is that for a long time, 3D printing had only expensive niche applications, and although progress has been astonishing, its uptake for mainstream manufacturing has been a long journey.
The journey is a lot longer than you think, and attempts to print with metal can be traced back to the 1880s, when arc welding first appeared. Welders soon realised that by using an additional sacrificial stick, a metal bead could be lain down and given a crude shape.
It had to wait for the invention of electron beams and vacuum chambers before that shaping began to look useful. Then, when the spray welding torch was replaced with a laser, many thought the revolution had begun.
Today, laser 3D printing of metal is certainly a hot technology for specialised products that can be produced no other way, but most machines are cumbersome and dangerous, usually needing to be sealed inside light-proofed workshops and operated remotely. Selective Laser Melting, Selective Laser Sintering, Direct Metal Laser Sintering, Laser engineered net shaping, directed light fabrication, and 3D laser cladding all have price tags in the hundreds of thousands. The typical 3D printing bureau or factory cannot afford to lease these machines, let alone buy them.
Laser 3DP has remained too slow for prototyping and too expensive for production.
Filaments based on PLA or ABS but infused with metal powders and binding agents have been around a while, for use in standard FDM printers. Basically, these produce metalicised or coated plastics or leave weak porous products that cannot rival cast products. Examples include Robocasting, binder jetting and magneto jet printing. Commercially viable mass production has remained elusive.
New printers are smashing down the barriers to mainstream 3D metal production. Desktop Metal now offer a desktop printer that is safe for use in the office or studio and ten times cheaper than laser based alternatives. It works similarly to FDM, extruding bound metal rods, but a microwave enhanced furnace sinters the printed parts, removing the binder and fusing the metal into a dense, stress-free product. Cloud-based software automates the workflow from the 3D printing bureau’s CAD design direct to print.
They also have a full-scale production method, called Single Pass Jetting, declared to be 100 times faster and 20 times cheaper than laser. It’s geared for the production of complex metal parts at high volumes, outperforming casting, because products need no additional tooling, and adding the key benefits of all 3DP – just-in-time production and customisation.
Others to watch
MarkForged also has an industrial metal printing method resembling FDM. It’s called ADAM and builds on the firm’s advances in carbon fibre printing. Aurora Labs of Australia have developed an affordable printer using “Acute Angle Printing”, sintering 99.5% dense metal products at layer thicknesses of 50 microns. MatterFab believe they can deliver a safe and affordable laser 3D printer.
Unsurprisingly all these new developments are attracting big investors, including BMW, Stratasys, GE and Google Ventures.