Editorial

Citation

Campbell, I. (2014), "Editorial", Rapid Prototyping Journal, Vol. 20 No. 3. https://doi.org/10.1108/RPJ-03-2014-0035

Editorial

Article Type: Editorial From: Rapid Prototyping Journal, Volume 20, Issue 3

Most of the papers in this issue relate to the additive manufacturing (AM) technique, commonly referred to as fused deposition modeling (FDM). It is not really surprising that we have seen a resurgence in research concerning this technology, as it provides the basis for many low-cost three-dimensional (3D) printers now arriving in the marketplace. For awhile, research in the area of FDM “took a back seat” to the work being done with laser fusion processes such as laser sintering or selective laser melting. These are seen as the most likely candidates for final part production using AM. However, Stratasys, the leading supplier of “top-end” FDM systems, has been demonstrating the versatility of the technique by introducing new materials such as aerospace plastic ULTEM 9,085, heat-resistant polyphenylsulfone and, most recently, nylon 12. This has increasingly moved FDM into the manufacture of end-use parts.

Several papers in this issue are related to understanding the mechanical properties of FDM parts, with a view to understanding their capabilities in end-use applications. In particular, the deposition-directional failure modes for polycarbonate are investigated in “Deposition direction dependent failure criteria for FDM polycarbonate”. The different mechanical properties across the junction between deposition “beads”, compared to within the beads, have always been seen as one of the limitations of FDM. However, if these can be properly modeled and predicted, then designers will be given the tools to work within these limitations. Variation within the FDM build process is also the focus of “The influence of support base on FDM accuracy in Z” and “Multi-material, multi-technology FDM: exploring build process variations”, with the latter looking at multi-material FDM. There has been increased interest in multi-material AM in recent years, as the possibilities it brings have been demonstrated by the Connex printers.

The low-cost opportunities provided by FDM are addressed in “Comparative evaluation of an open source FDM system”, which refers to an open-source system from Makerbot known as “Cupcake”. A benchmarking analysis was undertaken which compared the output from this printer with that from a much more expensive Stratasys machine. This showed that although the low-cost system experienced more thermal warping and higher surface roughness than the Stratasys machine, it was still able to keep almost 98 per cent of the measured dimensions within a tolerance of ± 0.5 mm (the higher cost system was able to hold 100 per cent of the dimensions to this tolerance). With additional development of these low-cost alternatives, it will be interesting to see how much closer they can come to the top-end machine performance.

Finally, “BeamMaker: an open hardware high resolution digital fabricator for the masses” in this issue introduces a low-cost 3D printer that uses an alternative process, more closely related to stereolithography. This is typical of the developments that are happening, as more of the original AM techniques are emerging from patented intellectual property protection. On the one hand, this is very exciting, but on the other hand, it could lead to confusion among users and potentially damage AM's reputation if (often over-optimistic) user expectations are not met.

Ian Campbell