The Deterministic Nature of Sensor-Based Information for Condition Monitoring of the Cutting Process

Round 1

Reviewer 1 Report

1. Thank you for submitting your paper. The work done here draws attention to a significant subject in condition monitoring using sensors for machining applications. I have found the paper to be interesting. However, several issues need to be addressed properly before the paper is being considered for publication. My comments including major and minor concerns are given below:
2. Please consider reviewing the abstract and highlight the novelty, major findings and conclusions. I suggest reorganizing the abstract, highlighting the novelties introduced. For example, line 15-16 are generic, it is not clear what exactly was concluded from this work, It should contain answers to the following questions:
3. What problem was studied and why is it important?
4. What methods were used?
5. What conclusions can be drawn from the results?
6. What is the novelty of the work and where does it go beyond previous efforts in the literature?
7. Just before the last paragraph in the introduction, the authors should answer the following question: What is the research gap did you find from the previous researchers in your field? Mention it properly. It will improve the strength of the article. This was not added according to previous comments.
   Materials and methods section is comprehensive and clear, however, images and graphs of equipment used, samples fabricated, and tests implemented with details on those images should be provided, this is an experimental study, and it is important to give sufficient information to the readers about the work done here.
8. The introduction needs more work and must be expanded, the authors must report on past studies similar or closely related to your current work, what did they do and what were their main findings then explain how your current work brings new knowledge and difference to the field.
9. Please avoid bulk citations such as in line 37 unless you give full credit to each of the citations.
10. Please avoid using we, us or our, please check this issue everywhere in the manuscript.
11. Please add more references from mdpi journals that are related to this work.
12. Please add a list of nomenclature for all the symbols and Greek letters used in the study at the end of the manuscript.
13. The introduction should be made from one section called “introduction” please remove the other subsections or rename them in a more proper way according to the journal template.
14. Section 4 please consider changing to “Materials and Methods”
15. Section 4 needs more work, some of the data reported in the lines 202-238 can be better presented in tables. Perhaps 2-3 tables, cutting parameters used, tools used, sensor setup..etc.
16. Section 4 is an important part of the manuscript, the authors should use images/figures to show the sensors, tests, test equipment and any other tools/methods used in the experimental part of the study. This will give a clearer idea of what was done in this work to the readers.
17. Please consider combining figures 2 and 3 in one figure and use (a) and (b) instead.
18. Line 263 what does the authors mean by changes significantly, please use either numbers or % to clearly show the readers what does significantly mean. For example, increased by xx or increase by x%.
19. Please consider combining figures 5 and 6 and using (a) and (b) instead.
20. Line 300 why the are no longer symmetrical, please explain this and support with references. You mention chatter as possible reason but is this a speculation? Or is it a fact or something which was found/reported in previous studies who for example investigated tool wear vs chatter. Please provide more comprehensive discussion and always support with references.
21. The results are merely described and is limited to comparing the experimental observation. The authors are encouraged to include a more detailed results and discussion section and critically discuss the observations from this investigation with existing literature.
22. Conclusion can be improved, please expand upon and use bullet points if possible. (1-2 bullet points for each of the subsections in the results and discussion sections.

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

In the abstract, I lacked information about the research methods used and why it was decided to use an experimental setup designed in such a way. The main results and conclusions drawn from them are also fairly poorly presented. It is not entirely clear who could be a potential recipient of them. I would advise you to extend the abstract with missing elements.

In keywords I would add: ‘sensors’ and ‘cutting process’.

In the ‘Introduction’ section, the authors present a literature review on the issue under study, but it is difficult to distinguish what the aim of the article is, what the hypothesis or research question is. It is also unknown what is the news that is supposed to be the result of the article. It is also hard to agree that Tool Condition Monitoring for cutting process is not well described and researched in the literature. Many articles in the MDPI 'Sensors' journal concern this issue.

The second section is devoted to determinism and chaos in cutting operations. It is not fully known what it is relation with the ‘Introduction’. A bit of a link is missing here. Determinism and chaos are present in many processes, so their occurrence or importance for the cutting process should also come as no surprise.

Section 3 could do with a more extensive justification of the indicators used. It is not entirely clear why the authors chose them. Please refer to the specific cutting process.

In section 4, the preparation of experimental work is described very vaguely. I would recommend presenting all the given data in the form of a table.

The 'Results and Discussion' section is written correctly, although it is unclear how it relates to the indicators in section 3. Additionally, it is not clear what the results are and how they can support the monitoring of tool wear in the cutting process. What are the benefits of considering determinism and chaos?

Incorrect numbering of the 'Conclusions' section - should be 6, but it is 5.

The conclusions do not mention the disadvantages of the proposed approach. There are also no indications of future research directions. It is good to indicate how the obtained results can be used and how they can contribute to the construction of modern monitoring tool systems.

There are many very old references in the literature. There is a lack of sources from the last 4-5 years, and yet during this period a lot of work was done in this research area. I would advise you to supplement the literature with the latest items.

Final conclusion: the topic of the article is up-to-date and important. More and more modern tool monitoring systems are in demand. However, it is hard to see a cause-and-effect structure in the manuscript. Many elements are poorly related to each other. I would recommend a very thorough supplementation of the text and the inclusion of the comments submitted.

Author Response

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Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

the authors have answered all questions and paper can be now accepted

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

Thank you very much for taking into account all my suggestions/comments. I am generally satisfied with the level of answers and many additions to the text.

It would still be possible to improve certain elements, e.g. formula notation - formula numbers should be right justified and centered, figures & tables caption is not correct. Authors should also try expand conclusions (indicate disadvantages of the proposed approach and compare the obtained results with others available in the literature). In addition, the format of Table 1 is not correct - please see editorial guidelines.

Please improve text in terms of editorial and language.

After corrections, the manuscript can be published in 'Machines' journal. I congratulate authors and I wish you more valuable papers. 

Author Response

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Author Response File: Author Response.pdf