Design, Calibration, and Troubleshooting of a Modular Low-Cost 3D Printer Based on Open-Source Technologies

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Dear authors,

thanks for preparing the manuscript. However, it is unclear how this goes beyond the state of the art of commercial or open source printers. Also there is no concrete figures concerning cost or what the speed / acceleration of the printer is.

If you claim open-source then the data of your printer such as CAD models, BOM and code should be publicly available.

Author Response

Reviewer 1

1. Does the introduction provide sufficient background and include all relevant references? Must be improved

Thank you for this observation. In the revised manuscript, we have strengthened the Introduction by expanding the background information on additive manufacturing and clarifying the motivation and research gap. We also incorporated additional references, to better contextualise the advantages and relevance of 3D printing. We hope the revised Introduction now provides a clearer and more comprehensive foundation for the study.

2. Is the research design appropriate? Must be improved

Thank you for this observation. In the revised manuscript, we clarified the nature and scope of the research design to make its purpose more explicit. The study is now clearly framed as an engineering development study, focusing on the design, assembly, calibration and troubleshooting of a low‑cost FFF 3D printer using accessible components. This positioning has been strengthened in the Introduction, in the Materials and Methods section, and in the Limitations, to reflect that the objective is functional validation rather than formal experimental optimisation. We also improved the structure and transparency of the methodology by reorganising the multi‑panel figures, providing detailed annotations, adding a consolidated technical‑specification table, documenting the firmware and slicing configurations, and expanding the explanation of the calibration workflow. These additions make the research design more coherent and reproducible, and we believe they address the reviewer’s concern.

3. Are the methods adequately described? Must be improved

Thank you for this observation. In the revised manuscript, we strengthened the Materials and Methods section by reorganising and expanding the descriptions of the mechanical, electronic, firmware and calibration procedures. Annotated multi‑panel figures were added to clarify assembly steps, wiring, software configuration and calibration workflow. A consolidated technical‑specification table and the exact slicing‑software version were also included to improve reproducibility. We believe these additions make the methodological description clearer and more complete.

4. Are the results clearly presented? Must be improved

Thank you for this comment. The Results section has been substantially clarified in the revised manuscript. We reorganised the multi‑panel figures, added detailed annotations, and introduced explanatory paragraphs for each stage of assembly, calibration and printing validation. Numerical values have been included to support the interpretation of dimensional accuracy, thermal stability and motion behaviour, and the comparison between pre‑ and post‑calibration performance is now explicitly presented. We hope these changes make the results clearer and easier to follow.

5. Are the conclusions supported by the results? Must be improved

Thank you for this observation. In the revised manuscript, we strengthened the link between the conclusions and the presented results. The Conclusions section now explicitly summarises the improvements demonstrated in the Results, such as the reduction of dimensional error after calibration, the confirmed thermal and motion stability, and the successful printing of more complex geometries. Additionally, a final paragraph was added to discuss the broader impact of the developed machine on educational, research and low‑resource contexts. We believe the revised text provides a clearer and better‑supported synthesis of the findings.

6. Are all figures and tables clear and well-presented? Must be improved

Thank you for this observation. In the revised manuscript, we improved the clarity and presentation of all figures and tables. Multi‑panel figures were reorganised and annotated to identify key components, fault locations and procedural steps. Each figure is now introduced in the text and supported by expanded captions that explain its purpose within the workflow. A consolidated technical‑specification table was also added to facilitate reproducibility. We believe these revisions significantly enhance the visual clarity and overall presentation of the manuscript.

7. It is unclear how this goes beyond the state of the art of commercial or open source printers. Also there is no concrete figures concerning cost or what the speed / acceleration of the printer is.

Thank you for this comment. In the revised manuscript, we clarified that the contribution of this work does not aim to outperform commercial or existing open‑source printers, but rather to address a gap in the documented, fully replicable construction, calibration and troubleshooting of low‑cost FFF systems using accessible components. This positioning has been strengthened in the Introduction and Discussion. To improve technical completeness, we added the approximate cost of the prototype (USD 350–450) and explicitly stated the motion parameters used during validation (50 mm/s printing speed and 3000 mm/s² acceleration). These details have been incorporated into the Methods and the consolidated technical‑specification table. We hope these additions address the reviewer’s concern.

8. If you claim open-source then the data of your printer such as CAD models, BOM and code should be publicly available.

Thank you for pointing this out. In the original submission, the Data Availability Statement did not accurately reflect the open‑source nature of the project, and we acknowledge this as our oversight. This has now been corrected in the revised manuscript. We have created a public GitHub repository to host the materials associated with the development of the printer. The repository currently includes the Marlin firmware folder, the design files, and the open‑source license (AGPL‑3.0), all of which are freely accessible at: https://github.com/mauricioamg26/Impresora-3d These materials reflect the core components used during the development and validation of the prototype. Some elements, such as a fully structured BOM spreadsheet or neutral‑format CAD files (STEP/STL), are not yet included because they require additional formatting and verification to ensure they match the final configuration documented in the paper. We have updated the Data Availability Statement accordingly, clarifying what is already available.

Reviewer 2 Report

Comments and Suggestions for Authors

• The problem statement and motivation of the study are not clearly defined. The authors are encouraged to clarify the research gap and explicitly state the purpose of the study. Additionally, numerical values should be included in the results section to improve specificity and scientific rigor.

• In the Introduction, the advantages of 3D printing or additive manufacturing are not sufficiently discussed. It is recommended that the authors elaborate on these advantages and support the discussion by citing relevant literature, such as Capability of 3D Printing Technology in Producing Molar Teeth Prototype, International Journal of Engineering and Applied Research (IREA), 8(2), 64, to enhance the quality of the manuscript.

• For Figure 1, the overall dimensions of the machine as well as the available printing volume should be clearly stated.

• A proper reference should be provided for the torque calculation, including the original source or foundational study from which the method was derived.

• A detailed technical specification of the newly developed machine (3D printer) should be included.

• The version of the Cura software used in this study should be specified, along with its origin and developer.

• The manuscript lacks sufficient analysis of the developed machine. This section can be strengthened by including performance evaluation and comparison with existing studies or previously developed FDM-based 3D printers.

• A conclusion discussing the impact of the developed machine on society, academia, researchers, and industry should be added.

Author Response

Reviewer 2

1. Are the results clearly presented? Must be improved

Thank you for this suggestion. In the revised manuscript we improved the clarity of the Results section by expanding the descriptions accompanying the figures, restructuring the multi‑panel images for better readability, and adding concise explanations that connect each result with the corresponding calibration or assembly step. Figures related to assembly, troubleshooting and printing performance were annotated and paired with short introductory paragraphs to help guide interpretation. We believe these changes make the presentation of the results clearer and more accessible.

2. The problem statement and motivation of the study are not clearly defined. The authors are encouraged to clarify the research gap and explicitly state the purpose of the study. Additionally, numerical values should be included in the results section to improve specificity and scientific rigor.

Thank you for this valuable suggestion. In the revised manuscript, we have strengthened the Introduction by explicitly defining the problem addressed, detailing the research gap and clearly formulating the purpose of the study. In particular, we now emphasise that existing work on low‑cost and open‑source 3D printers rarely provides fully replicable procedures for mechanical assembly, firmware configuration, calibration and troubleshooting, an aspect that motivates the present engineering development study. We have also added a more direct statement of the study’s objective and hypothesis, clarifying that the contribution lies in documenting a complete, replicable workflow rather than proposing new theoretical models or optimisation frameworks. Regarding the results, numerical values have been incorporated throughout Section 3.5 to improve specificity and scientific rigor, including dimensional errors before and after calibration, thermal deviations, motion‑accuracy measurements and extrusion‑flow correction. We believe these additions clarify the motivation of the work and enhance the transparency and precision of the reported results.

3. In the Introduction, the advantages of 3D printing or additive manufacturing are not sufficiently discussed. It is recommended that the authors elaborate on these advantages and support the discussion by citing relevant literature, such as Capability of 3D Printing Technology in Producing Molar Teeth Prototype, International Journal of Engineering and Applied Research (IREA), 8(2), 64, to enhance the quality of the manuscript.

Thank you for this helpful suggestion. In the revised version of the manuscript, we expanded the Introduction to briefly discuss the main advantages of additive manufacturing, such as fabricate complex geometries. This discussion is now supported by an additional citation, including the reference suggested by the reviewer, to reinforce the technological relevance of the topic. These additions strengthen the motivation and contextual framing of the study.

4. For Figure 1, the overall dimensions of the machine as well as the available printing volume should be clearly stated.

Thank you for this helpful suggestion. In the revised manuscript, we have added the external dimensions of the machine and the available printing volume directly in the text. We believe this addition improves the completeness and reproducibility of the mechanical description.

5. A proper reference should be provided for the torque calculation, including the original source or foundational study from which the method was derived.

Thank you for this helpful observation. In the revised manuscript we have added a reference to the classical formulation for power‑screw torque presented in Shigley’s Mechanical Engineering Design (Shigley et al., 2004), which is the basis for Equation (1) used in our torque estimation. The corresponding citation has been incorporated in Section 2.2.4.

6. A detailed technical specification of the newly developed machine (3D printer) should be included.

Thank you for this suggestion. In the revised manuscript, we added a consolidated technical‑specification table summarising the main mechanical, electronic and operational parameters of the developed 3D printer. This table integrates information distributed across Sections 2 and 3 and provides a clearer reference for researchers wishing to replicate the system.

7. The version of the Cura software used in this study should be specified, along with its origin and developer.

Thank you for this comment. In the revised manuscript, we now specify the exact version of Cura used in the study, together with its origin and developer. This information has been added to Section 2.3.2 to ensure clarity and reproducibility.

8. The manuscript lacks sufficient analysis of the developed machine. This section can be strengthened by including performance evaluation and comparison with existing studies or previously developed FDM-based 3D printers.

Thank you for this valuable suggestion. In the revised manuscript we expanded the Discussion section to include a brief qualitative comparison between the performance of the developed prototype and results reported in previous studies on low‑cost and RepRap‑based FDM printers. This addition highlights how the dimensional accuracy and operational stability achieved after calibration fall within the ranges documented for comparable open‑source machines. We also emphasise that, as an engineering development study, the work focuses on functional validation rather than on formal benchmarking. We hope this contextual analysis strengthens the interpretability of the results.

9. A conclusion discussing the impact of the developed machine on society, academia, researchers, and industry should be added.

Thank you for this suggestion. In the revised manuscript, we added a closing paragraph to the Conclusions section discussing the potential impact of the developed 3D printer on educational environments, research activities and low‑resource contexts, as well as its relevance for industry and technological adoption. This addition clarifies the broader implications of the work beyond the technical validation of the prototype.

Reviewer 3 Report

Comments and Suggestions for Authors

This paper designs a modular desktop fused filament fabrication (FFF) 3D printer based on open-source technology, breaking the barrier of high costs associated with commercial 3D printers and providing a replicable hardware solution. The system outlines the mechanical assembly, electronic integration, firmware configuration, and calibration processes of the printer, forming a reproducible technical manual suitable for educational and prototyping scenarios. The practicality of the modular design is verified, with its easy assembly and maintenance offering a convenient path for non-professional users to master 3D printing technology, while also providing a low-cost manufacturing system reference for fields such as machine design and automation.The shortcomings of this article and the recommendations are as follows:

1. The technical approach of this article does not break through the existing research framework; it only makes minor adjustments in component selection and fault resolution, without proposing new design, calibration, or optimization mechanisms, nor innovatively optimizing the modular design that is already widely used in the field of 3D printers.
2. The comparative experiments are missing, and no control groups such as commercial low-cost or other open-source 3D printers were set up, with the effectiveness verified only through comparisons before and after self-calibration.
3. The explanations of the charts and diagrams in the text are too brief, and the key components and fault locations in the diagrams are not clearly marked, which is not conducive to reader understanding and result reproduction.
4. The calibration process in this article is relatively simplified, lacking theoretical analysis. The 14% error in the feeding system calibration is only addressed by adjusting the step value through proportional calculation, without analyzing the root cause of the error or verifying the long-term stability of the correction.
5. The experimental data is recorded briefly, with the raw data of the core experiments not presented, and statistical indicators such as standard deviation and confidence intervals not provided, making it impossible to reflect the reliability and accuracy of the experimental data.
6. This paper does not provide detailed records of the specific parameters of the experimental components, equipment model specifications, operating procedures, or the complete configuration of firmware and slicing software, making it difficult for other researchers to replicate the experimental process and results.
7. Although solutions have been proposed for experimental failures such as wire feeding slippage, nozzle leakage, and shaft misalignment, the fundamental causes of these failures and their correlation with factors such as component selection and parameter settings have not been analyzed through experiments.
8. The performance evaluation metrics in this experiment are limited, relying solely on dimensional errors of simple geometries to measure device performance, and lack a systematic assessment of key indicators such as surface roughness, mechanical properties of printed samples, and long-term stability of the equipment.
9. In the introduction section, fourth paragraph, ninth line: the word 'nd' should be 'and'.

Author Response

Reviewer 3

1. The English could be improved to more clearly express the research.

Thank you for this comment. Following the reviewer’s suggestion, we carefully revised the manuscript to improve clarity, readability and consistency of the English throughout the text. Several sentences were rephrased to avoid long constructions, minor anglicisms were corrected, verbs were strengthened where appropriate, and repeated expressions were removed. These edits do not alter the technical content but enhance the overall presentation and make the description of the research more fluent and precise. We hope the revised version meets the expected language standard.

2. The technical approach of this article does not break through the existing research framework; it only makes minor adjustments in component selection and fault resolution, without proposing new design, calibration, or optimization mechanisms, nor innovatively optimizing the modular design that is already widely used in the field of 3D printers.

We thank the reviewer for this observation. We respectfully clarify that this article is intentionally positioned as an engineering development study. Its primary contribution lies in providing a documented replicable workflow for the development of an open‑source, low‑cost 3D printer. This contribution type aligns with high‑impact precedents in the field. For example, the seminal open‑hardware 3D printer work of Anzalone et al., published in the Q1 journal IEEE Access, prioritises practical engineering implementation and documentation. Similarly, the replication‑focused study by Omer et al., published in the Q1 journal Design Science, demonstrates that engineering development and replicability analyses constitute recognised scientific contributions in top‑tier venues. To make this scope explicit, we have revised the Introduction by adding a paragraph clarifying the nature of the contribution, and we have added a Limitations section. These changes ensure that the manuscript accurately reflects its intended purpose within the category of replicable engineering development studies.

3. The comparative experiments are missing, and no control groups such as commercial low-cost or other open-source 3D printers were set up, with the effectiveness verified only through comparisons before and after self-calibration.

We appreciate this observation. The present work is framed as an engineering development study. Within this framework, the validation aims to confirm functional performance and calibration consistency of the developed prototype rather than benchmarking it against external commercial or open‑source systems. Comparative performance evaluation, while valuable for optimisation‑driven studies, lies outside the scope of development‑oriented work, as recognised in high‑impact open‑hardware studies such as those by Anzalone et al. and Omer et al., where replicability and system functionality take precedence over cross‑device benchmarking. To clarify this scope, we have added a concise explanation of the validation approach in the Materials and Methods section and have explicitly stated in the Limitations subsection that no comparative experiments were conducted by design. These additions ensure transparency regarding the methodology and boundaries of the present contribution.

4. The explanations of the charts and diagrams in the text are too brief, and the key components and fault locations in the diagrams are not clearly marked, which is not conducive to reader understanding and result reproduction.

We thank the reviewer for this observation. In response, we performed a comprehensive revision of all figures and their supporting text to improve clarity, component identification and reproducibility. Across Sections 2.1–2.3, all multi‑panel figures were updated with explicit annotations. Additional explanatory paragraphs were added before each figure to guide the reader. Captions were rewritten to provide clearer, more informative descriptions. Section 3.1: Figures were reorganised into structured panels and labelled to identify parts and mounting hardware. Their introduction in the text was aligned with the step‑by‑step assembly narrative to improve coherence. Section 3.2: The full assembly images were annotated to highlight axis components, mechanical interfaces and the integration of subsystems. Fault‑related panels (e.g., burnt bushing, nozzle leakage) were clearly marked to identify failure locations and their causes, and the text now refers explicitly to the corresponding panels. Section 3.5: The pre‑ and post‑calibration prints were relabelled to indicate typical defects and the improvements observed after calibration. Each panel is now referenced at the exact point where it is discussed. Annotations distinguish functional improvements from residual non‑critical artefacts, consistent with the study’s development‑oriented scope.

5. The calibration process in this article is relatively simplified, lacking theoretical analysis. The 14% error in the feeding system calibration is only addressed by adjusting the step value through proportional calculation, without analyzing the root cause of the error or verifying the long-term stability of the correction.

We thank the reviewer for this observation. The calibration procedure has now been clarified and contextualised in the revised manuscript. In Section 2.5, we explicitly state that the proportional correction of the extrusion steps‑per‑unit follows the standard RepRap method widely used in open‑source FFF systems, where the extrusion mechanism exhibits an approximately linear response within normal operating conditions. As this work is positioned as an engineering development study, a corresponding explanation has been added to the Limitations section to clarify the intended scope of the study. Furthermore, we have added a note in Section 3.5 indicating that the corrected E‑steps value remained stable throughout the subsequent printing and calibration sessions, confirming short‑term operational consistency. We trust that these revisions make the calibration rationale, scope and methodological boundaries clearer.

6. The experimental data is recorded briefly, with the raw data of the core experiments not presented, and statistical indicators such as standard deviation and confidence intervals not provided, making it impossible to reflect the reliability and accuracy of the experimental data.

We appreciate the reviewer’s observation and understand the concern regarding the brevity of the recorded measurements. In line with this comment, we made several adjustments to clarify how the calibration data are presented reporting the nominal and measured values of the calibration test piece, together with the corresponding percentage error. And we clarified in the manuscript that the study is positioned as an engineering development exercise rather than an experimental investigation aimed at characterising statistical variability. As such, no repeated trials or formal statistical analysis were carried out. A short note has been added to the Limitations section to explain this more clearly. We hope these adjustments help clarify the purpose and boundaries of the measurements reported.

7. This paper does not provide detailed records of the specific parameters of the experimental components, equipment model specifications, operating procedures, or the complete configuration of firmware and slicing software, making it difficult for other researchers to replicate the experimental process and results.

We appreciate the reviewer’s observation and understand the importance of providing sufficient detail to support reproducibility. In the revised manuscript we have expanded the description of the key parameters and procedures across Sections 2 and 3 to clarify the configuration and operation of the system. In addition, and following the reviewer’s recommendation, we created a public GitHub repository containing the firmware configuration, design files and supporting documentation used in this work. The repository is openly accessible at: https://github.com/mauricioamg26/Impresora-3d We hope that these additions make the assembly, configuration and validation procedures easier for other researchers to reproduce. While this study is positioned as an engineering development study rather than an experimental optimisation, we have ensured that all parameters necessary to replicate the assembly, configuration and validation procedures are now explicitly presented.

8. Although solutions have been proposed for experimental failures such as wire feeding slippage, nozzle leakage, and shaft misalignment, the fundamental causes of these failures and their correlation with factors such as component selection and parameter settings have not been analyzed through experiments.

We thank the reviewer for this observation. We have clarified in the revised manuscript that the work is positioned as an engineering development study focused on documenting the assembly, calibration and troubleshooting, rather than on conducting experimental analyses. To address the reviewer’s concern, we expanded the qualitative discussion of the likely causes of each observed issue in Section 3.2. The corresponding panels in Figure 8 have also been annotated to explicitly identify these locations and the components involved. We additionally clarified in the Limitations section that the study does not include controlled experiments to quantify the correlation between design choices and failure behaviour, as this falls outside the scope of the development‑oriented objective of the work. The manuscript now explicitly states that the troubleshooting reported is based on practical engineering observation rather than experimental failure analysis. We hope these clarifications help better convey the intended scope of the study and the nature of the documented interventions.

9. The performance evaluation metrics in this experiment are limited, relying solely on dimensional errors of simple geometries to measure device performance, and lack a systematic assessment of key indicators such as surface roughness, mechanical properties of printed samples, and long-term stability of the equipment.

We appreciate the reviewer’s comment and understand the relevance of broader performance metrics in additive‑manufacturing research. In the revised manuscript, we clarified that the scope of this work is that of an engineering development study, rather than on providing a full performance‑characterisation study. To address the reviewer’s concern, we expanded the explanation in Section 3.5 to make explicit that the dimensional measurements presented were intended solely to confirm functional calibration and basic operational accuracy, which aligns with the development‑stage objectives of the prototype. We also added a note in the Limitations section indicating that advanced performance indicators such as surface roughness, mechanical properties of printed samples or long‑term stability tests were not included, as these would require a separate, more extensive experimental campaign beyond the intended contribution of this study. Nevertheless, we have strengthened the description of the post‑calibration behaviour by illustrating improvements in motion stability and extrusion consistency through annotated figures in Section 3.5, which complement the dimensional‑error assessment already provided. We hope these clarifications help better situate the evaluation metrics within the scope and goals of the present work.

10. In the introduction section, fourth paragraph, ninth line: the word 'nd' should be 'and'.

We thank the reviewer for pointing out this typographical error. The word “nd” has been corrected to “and” in the revised version of the manuscript.

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Dear authors,

it is still not clear what differentiates your project from many others out there. There is a lot of documentation also about the engineering of open source 3d printers. A list of projects with different foci can be found here.

Reviewer 2 Report

Comments and Suggestions for Authors

Satisfied, the authors have responsed all the comments.