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.
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