Adaptive benchmarking design for additive manufacturing processes

Abstract

Standards enabling the objective tolerancing and evaluation of dimensional and geometrical performances of additive manufacturing (AM) printers are still missing. The design, printing and measurements of geometrical benchmark test artefacts (GBTA) is the current solution proposed in literature. However, the current GBTA with fixed dimensions cannot cover most of the available printing area of printers with large building platform dimensions. This article proposes to solve this problem by developing an adaptive GBTA design whose main dimensions can be adapted to any common 3D printer. Moreover, an innovative design is implemented to decrease the risk of warping. The adaptive GBTA will then be used to characterise the performances of two different architecture material extrusion printers (Ultimaker 2+ and Pollen AM Series MC). Dimensional and geometrical accuracy, as well as top surface topography, were evaluated. The Ultimaker printer could reproduce features with maximum deviations below the tolerance interval (IT) 13 of the ISO 286-1, while the Pollen machine achieved a higher IT of 15 or 16. The highest geometrical deviations were observed for the coaxiality of cylinders oriented along the build direction (Ultimaker: 0.250 mm and Pollen: 0.497 mm). Top surface topography exhibited higher Ra values for Pollen (13.7 µm) than for Ultimaker 2+ (4.9 µm). The performances of the Pollen printer were lower than the Ultimaker machine in terms of surface topography, dimensional and geometrical accuracy. The proposed adaptive GBTA design covers most of the printing areas exhibited by Pollen and Ultimaker printers and offers flexibility to test other printers even with larger or smaller dimensions.

A Systematic Method for Assessing the Machine Performance of Material Extrusion Printers

“…The chosen design must ensure the best coverage of the ISO 286-1 dimensional size ranges achievable by the printer in its build platform while also ensuring the geometrical performance can be assessed owing to dedicated features (cylinders, hemispheres, planes, etc.). The part developed by Spitaels et al [20] (Figure 3) can be adapted to every material extrusion printer build platform owing to an adaptive geometry. It is designed to cover, as much as possible, the available size ranges of ISO 286-1 to allow the dimensional performance to be evaluated while ensuring the geometrical performance to be assessed through cubes, cylinders, and hemispheres.…”

“…Moreover, the innovative design of the part ensures a lower risk of warping, even though the part is very flat and, therefore, warping-sensitive. Finally, this part was successfully used to assess the dimensional and geometrical performance of an Ultimaker 2+ printer [20]. All of these reasons made this GBTA suitable for the planned machine performance study.…”

“…The Z axis is along the build direction. The features included in the GBTA allow 434 dimensional and 524 geometrical measurements to be performed [20]. The dimensional measurements are distributed over the size ranges of ISO 286-1 from 1 to 3 mm and 180 to 250 mm for the X and Y axes, respectively.…”

“…The data are then processed and can lead to the determination of the achievable geometrical and dimensional tolerance intervals [18]. Recently, ISO 52902 [19] presented a standard method decomposing a GBTA into several simpler parts focusing on accuracy, resolution, surface texture, and labeling [20]. Nevertheless, as explained by de Pastre et al in a recent review [12], even with this standard, the wide variety of processes and machine constructions makes the obtention of a universal GBTA part impossible.…”

Investigation of Part Quality Achieved by Material Extrusion Printers in Relation to Their Price

“…The quality characteristics of the surface roughness, dimensional accuracy, and geometric accuracy were measured using a self-developed sample [14]. An adaptive benchmarking approach was developed by Spitaels et al, which was used to compare two printers [15]. Cruz Sanchez et al performed a geometrical benchmarking of an open-source 3D printer, FoldaRap, in 2014 [16].…”