Of the various limiting factors affecting powder-bed additive manufacturing processes such as selective laser melting (SLM), this one is perhaps the most limiting of all: the build size, which is often less than one foot square.

However, an SLM machine developed by machine tool builder Adira makes big parts practical using a mobile chamber moving across the powder bed in such as way that a large piece can be built in sections.  The machine combines both powder-bed and metal-deposition AM into the same platform.

Large Travel 3D printed SLM part.
The part seen in this photo was built in one piece through SLM. This 316L stainless steel part is 900 mm long, or just under 3 feet. (Source: AM Magazine)

The large-travel SLM system is much more novel relative to other additive machines. One of the challenges of getting to large travels with a powder-bed machine is controlling the environment across such a large volume. Adira accomplished this with a smaller-volume chamber—just under one foot square—that travels the entire machine area and descends onto the powder from above to contain one section of material at a time. Building the sample part shown took about 80 hours, and the chamber was repeatedly in motion all throughout this time.

Click here for a video showing the machine movement, with the chamber advancing from section to section with each single build layer of the part.

>> Read more by Peter Zelinski, AM Magazine, January 20, 2017

Laser Cutting Specialist Develops Large-Travel Additive Approach