Production of 3D scientific instructional models using ender 3 neo 3D printer

Abstract

Keywords: 3D printing; equipment; pedagogic; skeleton; technology; understanding

Introduction

Cano (2015) observes that the term 3D printing covers a lot of processes and technologies that are used for the production of various materials ranging from auto parts to beef, human parts and plastic products. Essentially, what is common amongst the various techniques is that production is carried out layer by layer in an additive manner which is at variance with the traditional methods of production using the subtractive, sculpting and casting processes. Applications of 3D printing processes keeps evolving almost on a daily basis, and as this technology continues to permeate more deeply across industrial circles, awareness is created. Ford and Minshall (2018) avers that today, the world has only just begun to witness the true prospect of 3D printing. Fundamentally, the unique theory that drives 3D printing is that it is an additive manufacturing process; and this is indeed the nucleus of this study in the sense that 3D printing is a completely different manufacturing process that is hinged on advanced artificial intelligence robotic technology that build up various parts of products in an additive manner using layers in minute scales which is not the same with other techniques. Lipson and Kurman (2013) advanced the disadvantages in the conventional building that has essentially been built on handmade patterns. Many authors have written various books and materials about what 3D printing and additive manufacturing is essentially about but the efforts of this writers show a particular step-by-step manual of the production processes of scientific instructional materials like skeletons, the heart model, skull and other anatomical structures. Teaching of science subjects like Biology is easier handled with the use of concrete teaching apparatuses. And that is what this research is all about. In the light of the foregoing, this research seeks to delve into the unexplored domain of 3D printing of scientific models which, in the interim could be used as instructional materials in the teaching of science-based subjects like Biology. This research aims to pave a way for informed strategies that promote the integration of 3D printing within the confines of the creative landscape of Graphics. Through this exploration, this research aspires to contribute to the enrichment of artistic and scientific legacy, while simultaneously positioning various countries involved in it as the vanguard of technological innovation in the sciences, arts and design. Statement of the Problem Since the onset of the global recession, scientific instructional models have become difficult to procure from foreign manufacturers with the rise in the purchase of foreign exchange; moreover the models acquired by various institutions have become old and in a state of disuse and so, local production of these models has become a necessity and as graphic artists, these researchers have taken the initiative to produce these materials without further consulting foreign manufacturers; this will save cost and promote indigenous technology.

Aim and Objectives of the Study This study aims to produce scientific instructional materials for use in the teaching of Human Biology in Nigerian secondary schools and other research institutes. While the objectives are as follows: i. Gather data to know the state of use of scientific instructional materials in selected secondary schools in Nigeria. ii. Query the barriers, challenges, and factors that hinder the use of scientific instructional models in these schools iii. Produce these models iv. Distribute to schools to test their effectiveness as instructional materials

Materials And Methods

The methodology employed in this research is studio-based and practice-led where 3D printer was used in the studio to produce various models and apparatuses. Materials like 3D printer and different types and grades of filament and portable electric generating set were purchased to facilitate the seamless outcomes of this research as 3D printing technology has been found to save time and produce materials with precision and so at the end of this research, the models manufactured were used as instructional materials for the teaching of science students and for use in medical research institutions. Tools and materials employed in the production.

3. Prusa Slicer 2.7.4

These scientific instructional models were done using the Fused Deposition Modeling (FDM) method of 3D printing. The items produced are one complete structure of human skeleton, a skull and the heart vessel. Ahmad et al (2019) are of the view that 3D printing technology is useful in the area of dentistry for producing various types of teeth and in the same vein, these researchers, in carrying out this production took several steps; from the preparation of the digital model to post-processing of the printed parts were done and below are the production steps: The first step was to obtain a 3D Model, the items were acquired from Creality.com. Creality is an online repository where 3D Models can be purchased while other online repositories are, Thingiverse, GrabCAD and PursaSlicer. Secondly, the model was sliced using slicer software known as PrusaSlicer 2.7.4. Slicing is a crucial step in the 3D printing process, as it directly affects print quality, accuracy, and efficiency. In 3D printing technology, Horvath and Cameron (2020) sees “slicing” as the process of dividing a 3D digital model into thin, horizontal layers or slices. This is done to prepare the model for printing, as 3D printers create objects layer after layer as seen in Figure 1. The model of the skeleton was imported into PrusaSlicer Slt format. Slt is a file format used to represent 3D models, specifically designed for stereolithography (SLA) and resin 3D printing. It contains information about 3D model’s

Figure 1. PrusaSlicer showing a model of skeleton (screenshot by Onosigho, B.O. & Osaigbovo, F.O.). geometry, including the triangles that make up the model’s surface, as well as layer information for printing. The dark square area where the skeleton lies is a simulation of the print bed area whose area is 220 mm by 220 mm. The purposes of slicing as submitted by Prusa & Bach (2019) are as follows: i. To change 3D models into printable format: Slicing software converts the 3D model into a format the 3D printer understands. ii. To generate print paths: Slicing creates the print paths for the 3D printer to follow, ensuring accurate and efficient printing. iii. To determine layer height and thickness: Slicing software sets the layer height and thickness, which affects print resolution and speed. iv. To optimize print settings: Slicing allows for optimization of print settings, such as infill density, support material, and print speed. v. To prepare for print bed adhesion: Slicing ensures proper adhesion to the print bed, thereby preventing warping or detachment during printing. vi. To estimate print time and usage of material: Slicing provides estimates of print time and usage of material, helping with planning and resource allocation The green part in Figure 2 above shows the grid support style of structure; those parts are removable after the printing is completed. The brown colour of the skeleton of the image above is the default colour of all models imported into the slicer application and will not be the same as the final output whereas output colours will be dependent on the colour of the filament loaded in the printer. After

the above, perimeters in 2.0 was set for optimized printing as shown below in terms of the height, infill density, print speed, and support structures, the model was sliced simply by clicking on the slice button. The software automatically slices the model and the result can be seen visually in Figure 2 which is saved in G-code. 3D Printer Settings for Production of the full Skeleton Layer/Perimeters: Layer height – 0.3 mm First layer height – 0.35 Vertical shell – 3 mm Horizontal shell top – 3 mm Horizontal shell bottom – 3 mm Seam position – Aligned Support Material: Support style – Grid Top contact z distance – 0.2 (detachable) mm Bottom contact z distance – 0.2 (detachable) mm Support pattern – Rectilinear Pattern spacing – 2.5mm Top interface layers – 3 (heavy) mm Bottom interface layers – 3 (heavy) mm Interface pattern – Rectilinear Interface pattern spacing – 0mm XY separation between an object and its support - 50° Speed: Perimeters – 60 mm/s Small perimeters – 15mm/s External perimeters – 50% mm/s Infill – 80 mm/s Solid infill – 20 mm/s

Figure 2. PrusaSlicer showing s model of skeleton with support (screenshot by Onosigho, B.O. & Osaigbovo, F.O.). Top solid infill – 15 mm/s’ Support materials – 60 mm/s Bridge – 60 mm/s Gap fill – 20 mm/s Speed for non-print moves Travel – 130 mm/s Z travel – 0 mm/s Modifiers First layer speed – 30 mm/s The setting used for printing the skeleton in Figure 3 was also used to print two other models, a skull and the heart model. Below are the objects as at when they were imported into PrusaSlicer for slicing. The settings are not uttered most times except when there is change of material from PLA to ABS or PETG. Another reason that could make for resetting is only if the structure of a model changes and so it is not all models that needs support. Figure 4 is the heart model in the Prusa Slicer environment. The screen above shows a detailed breakdown of the printing time. Located at the top-left corner of the viewport is a transparent layer labeled “Legend” as seen in Figure 4. On the legend is the feature type which carries the breakdown of the time it will take to print the different parts of the model after being sliced. Table 1 below is the breakdown according to the parts that make up the model as displayed in Figure 4. The green area in Figure 5 are the support holding the overhangs in place, those parts were removed during the post-processing phase. Figure 6 reflects the white colour of the PLA filament used for the printing. These are the results after the post-processing stage. After slicing, the colour of models

Figure 3. 3D printed full skeleton after support has been removed (screenshot by Onosigho, B.O. & Osaigbovo, F.O.). turns from gold to orange with the support areas green as it shown in the screenshot in Figure 7. The skull model in Figure 8 was imported into PrusaSlicer and awaiting slicing, that is why the colour is gold. The setting used for the skel-

Figure 4. 3D printed full skeleton after support has been removed (screenshot by Onosigho, B.O. & Osaigbovo, F.O.). Table 1. Estimated printing time is 5 hrs 30 m Feature type

Findings

Figure 11. Ender 3 Neo 3D printer dimension: 440x440x465 mm (Photograph: Bennett Onosigho). Creality, a popular Chinese 3D printing company was used to print the above models. Some key features of the Printer • Open-frame design: A compact, open-frame structure with sturdy metal base and removable build plate. • Average built volume: A spacious build area of 220x220x250mm (8.66x8.66x9.84 inches) for printing objects. • Improved extruder: A redesigned extruder with tighter filament path and a more reliable hot-end for better print quality. • Upgraded electronics: A Creality-specific motherboard with a silent TMC2208 stepper driver for smoother and quieter operation. • Enhanced cooling: Improved cooling system with a larger heat sink and a more efficient fan for better temperature control. • Easy assembly: A semi-assembled kit with straightforward assembly process, suitable for beginners and hobbyists. When the G-code is opened with Microsoft notepad, the instructions for each slice are revealed as seen in Figur 12 and this is the path the print head follows layer by layer until the entire object is completely printed.

Based on these exercises, the following were ascertained about 3D printing: 1. 3D printing is mainly for rapid prototyping; it is quick for creating scale models or prototypes for testing.

2. It is good for the production of end-use products such

as consumer goods, machine parts or medical devices and not for mass production because of the time it takes to produce an item. From the above exercises, the larger the item, the more time it takes to complete printing a model. The skeleton full model took 8 hours, 20 minutes to complete, while the heart model and the skull took 5 hours 30 minutes and 5 hours, 35 minutes respectively. So, other larger objects could take up to days to print.

3. Steady source of power is needed to have a complete

smooth print. Once there is power outage, it interrupts the printing; however, manufacturers are upgrading their machines to resume prints when power is restored. Even at that, a slight shift is observed on the model which creates a kind of deformity on the model.

4. The space where the printing is been executed should

be air tight since other sources of air other than the one produced by the printer for cooling the models as printing progresses will result into stringing. Stringing is the spider like web created between points on print model especially where there are no supports.

5. Appropriate setting is the key to good print out-put.

Once there is error in the settings in such areas like the speed, retraction, cooling, style of support and temperature, it could result in defective output.

6. Filament breaking in the course of printing is a sign the

filament has expired. Unexpired filament will not break in the course of printing. 7. Only one colour can be printed at a time. Where different colours is desired which can only be applied hori-

zontally because of the movement of the nozzle in z axis, it is imputed in the settings. So, when a colour is to be changed, the printer will pause for the other colour of filament to be loaded after which the resume bottom is pressed for the printing to continue. But in a printing that has multiple extruders, filaments are loaded from the onset.

8. The feedback from the various secondary schools these

models were sent to for teaching purposes shows that the students understood the various concepts that these models were used better than previously taught without the use of concrete scientific instructional models.

Conclusion

This research effort explored the innovative intersection of 3D printing technology and scientific instruction, highlighting its significance in modern pedagogy, its applications across different educational levels and the potential benefits to students and instructors. The production of scientific instructional models using 3D printing technology according to Tryssen and Meier (2023) represents a paradigm shift in educational practices and a departure from the conventional two-dimensional learning aids to immersive three-dimensional representations. This shift not only facilitates a deeper understanding of scientific structures and processes but also fosters experiential learning, critical thinking, and problem-solving skills amongst students. In the light of this research development, this research has delved deeper into the potential applications, challenges, and future directions of utilizing 3D printing technology for scientific instruction. Bomorden and Papenbroch (2020) supports the idea of using 3D instructional models by examining case studies, educational initiatives, and emerging trends in science-graphics field and so these researchers sought to improve on the transformative impact of 3D printing on science education and inspire further innovation in pedagogy. This research effort has shown that teaching Biology in secondary schools better done using concrete scientific instructional models and it is recommended that future research efforts be done by other researchers to surpass the present research.

Ethics: There are no ethical issues with the publication of this manuscript. Peer-review: Externally peer-reviewed. Conflict of Interest: The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article. Financial Disclosure: The authors declared that this study has received no financial support.

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