Prusa I3 Research Articles

Mechanical Properties of 3D Printed PLA Scaffolds for Bone Regeneration

Abstract The growing interest in biodegradable scaffolds for bone regeneration created a need to investigate new materials suitable for scaffold formation. Poly(lactic acid) (PLA) is a polymer commonly used in biomedical engineering, e.g. in tissue engineering as a biodegradable material. However, the mechanical behavior of PLA along its degradation time is still not explored well. For this reason, the mechanical properties of PLA scaffolds affected by incubation in physiological medium needs to be investigated to show the potential of PLA to be used as a material for biodegradable scaffold formation. The purpose of this research is to determine the mechanical properties of PLA scaffolds before and after incubation, and to apply constitutive material models for further behavior prediction. Two sets of PLA scaffolds were printed by the 3D printer “Prusa i3 MK3S” and sterilized by ultraviolet light and ethanol solution. The first set of specimens was incubated in DMEM (Dulbecco’s Modified Eagle Medium) for 60, 120, and 180 days maintaining 36.5 °C temperature. The mechanical properties of the scaffolds were determined after performing the compression test in the “Mecmesin MultiTest 2.5-i” testing stand with a force applied at two different speed modes. The obtained data was curve fitted with the hyperelastic material models for a model suitability study. The second set of specimens was incubated in PBS (Phosphate Buffered Saline) for 20 weeks and used in a polymer degradation study. The obtained results show that the mechanical properties of PLA scaffolds do not decrease during incubation in physiological medium for a predicted new bone tissue formation period, though hydrolysis starts at the very beginning and increases with time. PLA as a material seems to be suitable for the use in bone tissue engineering as it allows to form biocompatible and biodegradable scaffolds with high mechanical strength, required for effective tissue formation.

Comparison of the Torsional Strength of Material Samples Made Using Selected Rapid Prototyping Methods

In recent years, there has been a marked increase in the use of rapid prototyping techniques that support industrial processes. The analysis of studies on strength tests of parts manufactured using additive techniques from model materials and hybrid composites usually includes tests of material and strength parameters based on uniaxial tension, bending, and compression tests. For elements manufactured from polymeric materials using traditional methods (e.g. injection moulding), data obtained from these tests are sufficient to determine the strength of the material and to apply the results in the product design process. In the case of the layered extrusion method, due to the model construction process, strength data based on standard samples do not have a direct transposition on the strength of machine parts operating under various load ranges, especially torsional loads. The publication presents the results of tests on the torsional strength of cylindrical samples with splines produced by layered extrusion, vacuum casting technology, and hybrid technology, which combines both technologies. The test samples were made using a Prusa i3 MK3 3D printer and the plasticised plastic modelling (fused filament fabrication, FFF) method, while PolyJet technology was used to create a reference model. The findings indicate that hybrid technology, in which a thin-walled mould is filled with a chemically hardened polymer, achieves the desired strength for the manufactured parts while maintaining dimensional accuracy and shape. The research results show that producing rotating elements using the hybrid technology reduces the sample core’s ability to undergo plastic deformation due to the adhesion between the materials and the occurrence of notches resulting from the model production process using the layered extrusion method.

On the suitability of additively manufactured gyroid structures and their potential use as intervertebral disk replacement - a feasibility study.

Intervertebral disk degeneration is a growing problem in our society. The degeneration of the intervertebral disk leads to back pain and in some cases to a herniated disk. Advanced disk degeneration can be treated surgically with either a vertebral body fusion or a disk prosthesis. Vertebral body fusion is currently considered the gold standard of surgical therapy and is clearly superior to disk prosthesis based on the number of cases. The aim of this work was the 3D printing of Gyroid structures and the determination of their mechanical properties in a biomechanical feasibility study for possible use as an intervertebral disc prosthesis. Creo Parametric 6.0.6.0 was used to create models with various Gyroid properties. These were printed with the Original Prusa i3 MK3s+. Different flexible filaments (TPU FlexHard and TPU FlexMed, extrudr, Lauterach, Austria) were used to investigate the effects of the filament on the printing results and mechanical properties of the models. Characterization was carried out by means of microscopy and tension/compression testing on the universal testing machine. The 3D prints with the FlexHard and FlexMid filament went without any problems. No printing errors were detected in the microscopy. The mechanical confined compression test resulted in force-deformation curves of the individual printed models. This showed that changing the Gyroid properties (increasing the wall thickness or density of the Gyroid) leads to changes in the force-deformation curves and thus to the mechanical properties. The flexible filaments used in this work showed good print quality after the printing parameters were adjusted. The mechanical properties of the discs were also promising. The parameters Gyroid volume, wall thickness of the Gyroid and the outer wall played a decisive role for both FlexMed and FlexHard. All in all, the Gyroid structured discs (Ø 50mm) made of TPU represent a promising approach with regard to intervertebral disc replacement. We would like to continue to pursue this approach in the future.

Dual feed progressive cavity pump extrusion system for functionally graded direct ink write 3D printing

Material extrusion Additive Manufacturing (AM), is one of the most widely practiced methods of AM. Fused Filament Fabrication (FFF) is what most associate with AM, as it is relatively inexpensive, and highly accessible, involving feeding plastic filament into a hot-end that melts and extrudes from a nozzle as the toolhead moves along the toolpath. Direct Ink Write (DIW) 3D printing falls into this same category of AM, however is primarily practiced in laboratory settings to construct novel parts from flowable feedstock materials. DIW printers are relatively expensive and often depend on custom software to print a part, limiting user-specificity. There have been recent advancements in multi-material and functionally graded DIW, but the systems are highly custom and the methods used to achieve multi-material prints are openly available to the public. The following article outlines the construction and operation method of a DIW system that is capable of printing that can produce compositionally-graded components using a dual feed progressive cavity pump extruder equipped with a dynamic mixer. The extruder and its capabilities to vary material composition while printing are demonstrated using a Prusa i3 MK3S+ desktop fused filament fabrication printer as the gantry system. This provides users ease of operation, and the capability of further tailoring to specific needs.

The Development of a Rehabilitation Orthotic Walker with a Real-time Visual Feedback System of the Gait Symmetry

Patients who suffer from a disability or face temporary walking difficulty due to accidents or medical conditions have to go through rehabilitation treatment, which requires them to use an orthotic walking assistive device such as a walker, cane, or crutches. It is estimated that there are more than 7.4 million people in the world who depend on walkers to assist them in their walking either due to a disability, old age, or as a part of their rehabilitation following accidents or medical conditions. The use of orthotic assistive devices may last for several weeks or months and encourage patients to keep the weight off the injured or weak limb and exert more force on the healthy limb. Such prolonged use of walking assistive devices and heavy reliance on healthy lower limbs may cause negative gait disorders for patients. Negative gait disorders are due to unbalanced gait because of the lack of continuous feedback to patients about their gait. Physical therapist feedback to patients is limited to their physical presence with patients; hence, it is not practical to give the patient corrective feedback about their gait with every walking step. Hence, to overcome this pitfall, a visual feedback system of the gait symmetry, which could be installed on any traditional rehabilitation orthotic walker, was designed, developed, and proven. The visual feedback system was 3D modeled utilizing SolidWorks 2021, and parts were 3D printed utilizing the Original Prusa i3 MK3S+ 3D printer. This real-time visual feedback system relies on load cells installed in the tips of the orthotic walker legs to measure the force and weight being exerted on each side of the orthotic walker. The visual feedback system was tested to give the patients visual feedback, encouraging them to correct their unbalanced gait by shifting their weight bearing on either of their two lower limbs. This novel and innovative system mitigates the negative effects of the traditional orthotic walker on the overall gait and helps to mitigate negative gait disorders in patients.

Mechanical behavior of recycled FDM printed parts from PETG in the circular economy

The aim of this paper was to observe the behavior of recycled 3D printed polyethylene terephthalate glycol (PETG) specimens and 3D printed raw specimens. In order to extrude the recycled grains into a filament, a Felfil evo filament extruder was used. The recycled filament was extruded from PETG at a temperature of 195°C and with a speed of 7 rpm according to the manufacturers’ requirements. Subsequently, different colors of the raw filament were printed on tensile specimens using Prusa i3 MK3S Original to compare the results between the recycled filament and the manufactured one. After printing the samples, the tensile tests were performed on the Zwick machine, with a capacity of 5KN. For the determination of the strain state in the test specimens, digital image correlation was used. A good correlation between the results was observed. Digital image correlation helped to better understand of the distribution of true principal strain in the recycled and raw specimens.

Information Modelling of Extrusion-based 3D Printing Process for Digital Twins

This paper focuses on the information modelling of the extrusion-based 3D printing process. It aims to facilitate the creation and management of a digital twin (DT) through a comprehensive understanding of the manufacturing process. The workflow of extrusion-based 3D printing, spanning from the CAD model to the printed part, is analysed and modelled using the Integration Definition for Process Modelling 0 (IDEF0) method. Building upon the IDEF0 model and relevant literature, a Petri net is developed to identify specific information and logic inherent to the printing process. The identified elements are subsequently filtered by the specific purpose of the DT and categorized into three classes: Component, Activity, and Property. Specifically, this study explores the material extrusion (MEX) process as implemented by the Prusa i3 MK3 printer. Derived from functional flow block diagrams and mathematical formulas, the information model consists of 21 components, 25 activities and 83 properties. This model can be considered as an information repository, which enables DTs to consider, select and synchronise specific physical information elements in their digital representation within the context of the MEX process.

Design and Printing of a Case for an Arduino System

AbstractThis article will be presented the stages of making a two‐component housing, for the protection and stability of a system that is implemented on an Arduino data acquisition and acquisition board. The housing has the actual body and cover, implicitly four inner pillars, which will present the stability in the housing of the system. The design and printing stages of this element of the mechatronic system will be identified. The design will be done with the help of the Solidworks program, and the printing will be done with the Prusa I3 printer.

Towards a general model to predict energy consumption for fused filament fabrication

Additive manufacturing offers the opportunity to manufacture highly complex parts capable of providing improved performance, such as using lattice structures inside parts to reduce part weight. However, further research and development is required to improve the energy efficiency of the machinu85es, given the growing focus on sustainability and sustainable manufacturing. The purpose of this research is to address the interaction between part geometry, layer thickness, and printer type to minimize energy consumption for fused filament fabrication. This experiment was conducted with a Creality Ender 3, Monoprice MP Voxel, and Prusa i3 MK 3S + 3D printers using PLA filament, with two different part geometries and two settings for layer thickness. Active power during printing was recorded during warmup and printing. Energy consumption varied with printer type and layer thickness, while increased part complexity may lead to larger energy consumption. For printer selection, other factors may influence decision making of fused filament fabrication users such as quality and machine cost which have tradeoffs when compared to energy consumption. The first and second energy prediction models evaluated in this study had relatively large mean absolute error of 58 kJ and 29 kJ, when calculated using previously derived empirical coefficients and build time estimates calculated using slicing software, respectively. Our research suggests that improvements in the accuracy of energy prediction models are needed so such models can be applied to a range of printers. This research has implications for additive manufacturing service providers, makerspaces, as well as hobbyists who want to advance the sustainability of additive manufacturing.

PMMA Cranioplasty Making by Using Open-Source CAD Software, PLA Printers, and Silicone Rubber Molds: Technical Note with Two Illustrative Cases.

We read with great interest Malikov et al's case report/technical note entitled “PMMA cranioplasty making by using open-source CAD software, PLA printers, and silicone rubber molds: technical note with two illustrative cases.”[1] We were the first in the literature to begin an ultra-low-cost patient-specific polymethyl methacrylate (PMMA) cranioplasty implant service in Pakistan, that too in a public sector hospital, and we have already published our technical note and limited case series with 1-year follow-up.[2] Since then, our technique has been adopted by our colleagues at neighboring centers, and we have amassed an experience of over 50 cases, and many of our patients are in long-term follow-up. At the national level, the lowest cost offered by commercial companies for a patient-specific PMMA implant exceeded US$ 1,000 and US$ 10,000 for titanium and polyetheretherketone (PEEK) hemicraniectomy implants, respectively. The vast majority of the Pakistani population are poor and underprivileged, and the trauma cohort who require this operation are actually those who could never meet these costs in their lifetime. Free-hand PMMA cranioplasty was utilized in virtually all cases nationally. After beginning our initial service, the total cost to manufacture an implant in consumables was US$ 40. The printer we used was a locally assembled Chinese Prusa i3 clone. Thus, production cost was exponentially cheaper than commercial rates, and in our experience, our clinical and aesthetic outcomes are the same, if not better. Naturally, when one intends to offer a service for the patient benefit rather than profit, affordability is one of the most important parameters, especially in the impoverished developing world. We would be delighted to know the exact specification of the printer used by Malikov et al, the cost of disposables and printing of each implant, and the context of this cost in their patient's socioeconomic demographic/health care system, and whether commercial options were as extortionate for their general public as it was for ours.

Was a 3D-printed firearm discharged? Study of traces produced by the use of six fully 3D-printed firearms

Since the blueprints of the Liberator were published and successfully tested, countless new designs for said 3D-printed firearms and 3D-printed firearm components have been created and made publicly available. These new 3D-printed firearms, which are praised by their designers as ever more reliable, can be found on the Internet with little effort. Press reports have shown that various models of 3D-printed firearms have already been confiscated by law enforcement services around the world. So far, forensic studies have addressed this set of problems relatively little, whereby for the most part only the Liberator has been examined in detail and three other designs were only included a few times. The rapid pace of this development poses new challenges for forensic investigations and unveils new spheres of investigation regarding 3D-printed firearms. This research initiative aims to determine whether the results from previous studies on Liberators, are also reproducible and observable when using other models of 3D-printed firearms. In this respect six fully 3D-printed firearms – PM422 Songbird, PM522 Washbear, TREVOR, TESSA, Marvel Revolver and Grizzly – were produced on a material extrusion type Prusa i3 MK3S using PLA as the material. Test firings of these 3D-printed firearms have shown that they are indeed functional, but that, depending on the model, they suffer different levels of damage when fired. However, they were all rendered inoperative after one discharge and could not be used for further discharges unless the broken pieces were replaced. As in other studies, the firing process and the resulting ruptures on the 3D-printed firearm, projected polymer parts and fragments of different sizes and in different quantities into the immediate environment. The parts could be physically matched, allowing the reconstruction and identification of the 3D-printed firearms. Elements of ammunition also showed traces of melted polymer on the surface and cartridge cases bore tears or swellings.

183. Customizable, Biocompatible And Low-cost 3D Printed Implants For Craniofacial Reconstruction

PURPOSE: Craniofacial reconstruction or enhancement requires autologous, cadaveric or alloplastic implants, often requiring intraoperative modification to optimize shape and fit for a particular patient, introducing associated risks of infection, extrusion, expense and donor site morbidity. Given this, there is substantial need for biocompatible, customizable and low-cost facial implants. This study examines the biocompatibility and durability of various polylactic acid (PLA) implant designs +/- decellularized cartilage infill to assess translatability to craniofacial reconstruction. METHODS: Cartilage harvested from ovine ribs was minced or zested and decellularized. Using 3D modeling software, dorsal nasal scaffolds were custom-designed with contours similar to commercially available silicone implants. Scaffolds were printed in polylactic acid (PLA) on a PRUSA i3 MK3S+ printer and implanted subcutaneously on rat dorsa. Two scaffolds were designed as external “cages” of low or high porosity and were without internal supports. These cages were implanted empty or with either minced or zested decellularized cartilage infill, yielding 6 total treatment groups, n=4 each. The remaining two scaffolds had internal PLA filament supports and were implanted without decellularized cartilage infill. Scaffolds were explanted 3 and 6 months after implantation, after which they underwent same-day volumetric analysis via microCT, then Formalin-fixed and embedded in paraffin and sectioned at 10μm for histopathologic analysis. RESULTS: Volumetric analysis of explants at 3 and 6 months revealed retention of implant contours and volume across rebar and minced cartilage-filled scaffolds. Tissue ingrowth between cartilage particles was evident between 3 and 6 months on MicroCT. Empty and zested cartilage-filled cages displayed significant volume loss relative to volume at implant (p < 0.05) with explanted constructs grossly collapsed; intergroup comparison revealed rebar and minced cartilage-filled constructs had superior volume retention relative to empty and zested cartilage-filled cages (p < 0.05). Histopathology with hematoxylin and eosin and safranin-O stains at the 3 versus 6-month timepoints indicated resolving lymphocytic inflammatory response, increased tissue vascularization and improved collagen deposition. CONCLUSION: This study shows that PLA facial implants with sufficient internal supports are a feasible and safe alternative to current craniofacial reconstructive implant options. The biocompatibility of PLA and decellularized cartilage infill promotes ingrowth of healthy tissue with collagen deposition and neovascularization. Further, design and fabrication of these implants can be completed quickly and at minimal cost, allowing for affordable custom-printed implants with a minimal risk profile.

3D Printing of Individual Running Insoles - A Case Study.

The study's starting point is to find a low-cost and best-fit solution for comfortable movement for a recreational runner with knee pain using an orthopedic device. It is a case study. The research aims to apply digitization, CAD/CAM tools, and 3D printing to create an individual 3D running insole. The objective is to incorporate flexible shape optimization would provide comfort reductions in foot plantar pressures in one subject with knee pain while running. The test hypothesis was if it is possible to make it from one material. For this purpose, we created a new digital workflow based on the Decision Tree method and analyzed pain and comfort scores during user testing of prototypes. The input data were obtained during a professional examination by a specialist doctor in the orthopedic outpatient clinic in the motion laboratory (DIERS 4D Motion Lab, Germany) with the output of data on the proband's complex movement stereotype. Surface and volumetric data were obtained in the biomedical laboratory with the 3D scanner. We modified the digital 3D foot models in 3D mesh software, developed the design in SW Gensole (Gyrobot, UK), and finally incorporated the internal structure and the surface layer of the insole data of the knowledge from the medical examination, comfort analyses, and scientific studies findings. Four complete 3D-printed prototypes (n=4) with differences in density and correction elements were designed. All of them were fabricated on a 3D printer (Prusa i3 MK3S, Czech Republic) with flexible TPU material suitable for skin contact. The Participant tested each of them five times in the field during a workout and final insoles three months on the routine training. A novel workflow was created for designing, producing, and testing full 3D-printed insoles. The product is fit for immediate use.

Study of selected properties of PLA used in 3D printing

This study focuses on determining the best possible structure of the orthosis made with FDM 3D printing technology. To produce the samples, a thermoplastic PLA material was selected that met the conditions of biodegradability, biocompatibility and non-toxicity. The samples produced were subjected to a tensile strength test and corrosion resistance.Studies based on FEM analysis were carried out using the advanced engineering software CAE - Inventor. The samples were designed in the CAD system, while the G-Code path was generated using the PrusaSlicer 2.5.0 program dedicated to the Prusa i3 MK3S+ printer, which was used to create the models. Surface morphology observations of PLA were carried out with a Zeiss SUPRA 35 scanning electron microscope (SEM). The static tensile test was performed on the Zwick/Roell z100 device based on the PN-EN ISO 527:1 standard. Electrochemical corrosion tests were carried out using the Autolab PGSTAT302N Multi BA potentiostat in Ringer solution at a temperature of 37C.The research allowed the appropriate structure of the orthosis made of PLA polymer material using 3D FDM printing technology. The static tensile test, SEM and corrosion tests confirmed the correct application of this material for the selected purpose. It was possible to determine that samples with holes of 10 mm had the highest strength properties. Due to the tensile tests, the average tensile strength of those samples was around 61 MPa. The corrosion parameters of PLA were determined using Tafel analysis.The research methodology proposed in work can be used to study other biomedical materials. The results presented can be the basis for further tests in order to search for the best orthopaedic stabiliser.The innovative part of the article are three different versions of structures intended for making orthoses used in medicine.

EFFECTIVE POROSITY OF 3D PRINTED SURGICAL MESHES

Abstract Introduction According to previous studies, pore size and geometry are crucial factors to assure good clinical results for surgical meshes [refs]. Although commercial surgical meshes are commonly knitted, 3D printing has recently been used to provide additional properties to them [refs]. In general, the mechanical properties of 3D printed meshes are worse, but geometrical control is better than in knitted ones. In this study, a comparison of effective porosity between knitted and 3D printed surgical meshes was performed. Methods Pore size and geometry were characterized through optical brightfield microscopy (Nikon E100) and quantified using ImageJ v.1.53e. Several geometries of 3D printed meshes with polypropylene (Prusa i3 MK3 and Smartfil filament) and commercial polypropylene Assumesh meshes (Assut Europe) were evaluated. The 3D printed geometries were triangular and honeycomb while the commercial meshes were knitted. Results 32.38, 18.65 and 17.26% of the total area of the commercial, triangular and honeycomb meshes were porous, respectively. Although effective porosity was homogeneous on commercial meshes (2.71±0.07 mm2), pore size was smaller in honeycomb (0.088±0.071 mm2) and bigger in triangular (0.201±0.063 mm2) than in commercial meshes (0.105±0.030 mm2). Conclusions Some imperfections are generated during the extrusion of filaments that contributes to non-uniform pores in 3D printed meshes. Hence, a post-processing of meshes will be recommended to take advantage of the higher precision of 3D printing.

Exploiting deep learning and augmented reality in fused deposition modeling: a focus on registration

The current study aimed to propose a Deep Learning (DL) based framework to retrieve in real-time the position and the rotation of an object in need of maintenance from live video frames only. For testing the positioning performances, we focused on intervention on a generic Fused Deposition Modeling (FDM) 3D printer maintenance. Lastly, to demonstrate a possible Augmented Reality (AR) application that can be built on top of this, we discussed a specific case study using a Prusa i3 MKS FDM printer. This method was developed using a You Only Look Once (YOLOv3) network for object detection to locate the position of the FDM 3D printer and a subsequent Rotation Convolutional Neural Network (RotationCNN), trained on a dataset of artificial images, to predict the rotations’ parameters for attaching the 3D model. To train YOLOv3 we used an augmented dataset of 1653 real images, while to train the RotationCNN we utilized a dataset of 99.220 synthetic images, showing the FDM 3D Printer with different orientations, and fine-tuned it using 235 real images tagged manually. The YOLOv3 network obtained an AP (Average Precision) of 100% with Intersection Over Unit parameter of 0.5, while the RotationCNN showed a mean Geodesic Distance of 0.250 (σ = 0.210) and a mean accuracy to detect the correct rotation r of 0.619 (σ = 0.130), considering as acceptable the range [r − 10, r + 10]. We then evaluate the CAD system performances with 10 non-expert users: the average speed improved from 9.61 (σ = 1.53) to 5.30 (σ = 1.30) and the average number of actions to complete the task from 12.60 (σ = 2.15) to 11.00 (σ = 0.89). This work is a further step through the adoption of DL and AR in the assistance domain. In future works, we will overcome the limitations of this approach and develop a complete mobile CAD system that could be extended to any object that presents a 3D counterpart model.

Influence of UV Ageing on Properties of Printed PLA Containing Graphene Nanopowder.

The present paper analyses the properties of printed polylactic acid (PLA) samples with admixtures of graphene nanopowder (GNP) at wt. 1%, 2% and 4%. The pure polylactide and admixed polylactide printed samples were examined to determine their chemical-physical properties, stiffness, and strength parameters. The tests of tensile, dynamic mechanical analysis (DMA), difference thermogravimetric (TG), and differential scanning calorimetry (DSC) were executed before and after UV (ultraviolet) treatment. The first part of the paper shows the process of manufacturing granulates and filaments mixed with graphene. The second part of the paper concerns the results of the tests made on printed samples. The analysed samples were printed using a Prusa i3 MK3 printer. It transpired that the content of graphene at 1% improved the mechanical parameters of the printed composite by organising its structure. Increasing the amount of graphene caused the values of the measured parameters to drop. This research indicates how important it is to determine the optimal values of nanoadditives in biopolymers.

Damage assessment of different FDM-processed materials adopting Infrared Thermography

The use of components obtained through the additive manufacturing (AM) technique has become increasingly widespread in recent years, playing a central role in industrial production, and in particular in some fields such as automotive, biomedical, aerospace and electronics. Among all AM techniques, FDM (Fused Deposition Modelling) represents the most used printing technique to produce polymeric and composite components, thanks to the flexible printing process, the low cost and the diversity of the materials adopted. The aim of the present work concerns the comparison between the mechanical properties of three plastic materials printed with the FDM technique (polylactic acid PLA, polyethylene terephthalate glycol-modified PETG and Acrylonitrile-butadiene-styrene ABS) using an Original Prusa i3 MK3S, by varying the raster angle between 0°, 45° and 90° degrees. Infrared Thermography has been adopted to monitor the temperature evolution during static tensile tests and to assess stress level that can initiate damage within the material. Failure analysis was performed to correlate the mechanical behaviour with the microstructural characteristics of the materials.

Effect of the manufacturing parameters on the tensile and fracture properties of FDM 3D-printed PLA specimens

Fused Deposition Modeling (FDM), also known as material extrusion, is currently one of the most popular Additive Manufacturing (AM) technology on the market. In this study, two commercial FDM printers (Prusa i3 MK3 and WN400 3D Platform) were used for layer-by-layer manufacturing of polylactic acid (PLA) Dog Bone (DB) and Single Edge Notched Bend (SENB) specimens, aimed at investigating the influence of the manufacturing parameters on the tensile and fracture properties of PLA elements obtained by FDM technology. The effects of growing direction (horizontal and vertical), building orientation (0°, 45° and 90°), printer type, layer thickness (0.15 and 0.40 mm), specimen thickness (4 and 10 mm) and filament color (purple, white, black, gray, red, orange) are discussed in detail. Tensile tests were performed on DB specimens, while fracture mechanics tests on SENB specimens. Both the tensile and fracture properties of FDM 3D-printed PLA specimens have been found to be dependent on the investigated manufacturing parameters. From the microstructural analyses of the SENB fracture surfaces, it has been observed that the fracture mechanisms and crack propagation is a step-wise process. Finally, the material properties charts (Young’s modulus and mode I fracture toughness versus tensile strength) are plotted.

Accuracy of build time and mass estimates from slicer software for fused filament fabrication

There is growing interest to optimize the fused filament fabrication process to produce quality products and make it more energy efficient. One of the ways to help achieve this is by initially obtaining accurate build time and mass estimates from 3D printing slicer software to assess the energy consumed by 3D printers. This paper aims to compare the accuracy of build time and mass estimates of three different slicer programs, including Simplify3D, Cura and PrusaSlicer, through experiments for certain parameter settings. An Ultimaker 3 and Prusa i3 MK 3S+ printer are used for the estimates and actual experiments. The mean absolute error for each slicer software is quantified and the results are compared to assess accuracy. The mean absolute error of the build time estimate for Simplify3D, Cura, and PrusaSlicer was 55.25 min, 49.5 min, and 203.25 min, respectively. The mean absolute error of the mass estimate for Simplify3D, Cura, and PrusaSlicer was 4.49 g, 6.25 g, and 9.07 g respectively. The results show that slicer software tend to overestimate mass, while over or under predicting build time, depending on the printer and process parameters. Simplify3D and Cura provide the most accurate build time and mass estimates. The results indicate that Simplify3D and Cura estimates show promise for use in energy efficiency and material consumption analysis.