Research into the Impact of Spindle Speed and Feed Rate Changes on the Life of a Deep-Drilling Technology Tool

Round 1

Reviewer 1 Report

Abstract:

• The abstract summarizes the work carried out. The concept and the goal of the study are clear.
• When you specify the l/D ratio, its value is 5-10 and not ’5-10 D’. The length of a long bore is 5-10 D.
• In the abstract the main finding should be mentioned concretely in one or two short sentences.

Introduction:

• The literature review is a good foundation of the problem. It includes enough cited up-to-date studies.
• This section should include the novelty of the study and the academic or industrial contribution.
• A few sentences would be useful in which the authors summarize the planned experimental work, e.g. ‘Experiments were carried out to analyze a gun drill tool…’

Deep hole drilling:

• The l/D should be given precisely here too (row 111).
• This section conceptually should be put in the introduction. It includes literature information.

Analysis of deep drilling technology…:

• The first paragraph conceptually should be put in the introduction.
• The second paragraph is about methodological issues. It would be useful to add a ‘methodology’ section to the manuscript. Such a section should include the draft of the tool and their parameters, and all the information that takes place now in section 4.
• The ishikawa diagram is a good summary of the root-causes, however there is a serious methodological problem here: how the causes were collected and who did it (deeper specification is missing)? Based on what were the main affecting factors designated?

Testing the life…:

• The type of the machine tool is ZAH620 or ZAH720?
• Please highlight that the tool was designed and produced in-place. I think this is the case. If not, the exact specification (type) of it is needed. This is shady from the text.
• The tool holder also should be specified. Not only the manufacturer but the type is needed too.
• In table 1 not the exact chemical composition is demonstrated, the table includes limits and not exact, measured values. Please delete the word ‘exact’.
• It I enough to provide maximum two versions of the material, e.g. the 16MnCr5 and EN 10184. Actually, 16CrMo5 is included in the text. I think this material is the 16MnCr5.

Statistical evaluation:

• Figure 6 and 8: Please explain the meaning of Auger1, 2, … and its 10 number. It is not clear from the text.
• The ANOVA is correct and well-presented.
• In Eq.1 please provide the standard notation of the speed. The dependent variable should also be included in the formula. In Eq. 2 the speed is x. And later too! Please be precise with the used variables and parameters.
• In Eq 3 the sign of partial derivative is not correct! Please apply the standard mathematical formulation.
• The above mentioned editing problems are valid later when the effect of feed is analyzed.

Recommended conditions:

• This section summarizes the results-based recommendations in a clear manner.
• However, the dimension of speed is not rpm (revolution-per-minute). Speed is a velocity variable the dimension of rpm is 1/s or similar.

Conclusion:

• The conclusion section includes the main findings and they are summarized clearly.
• This section should include the limitations of the study / experiment and the possible extension of it.

Overall evaluation:

• The concept of the experiments is basically good. The results are clearly presented. There are no conceptual errors in the manuscript.
• It seems that the authors did not spent enough time for the ‘little’ things: standard variables and parameters, exact, precise formulation, correct dimensions, etc.
• The language of the manuscript is poor: grammar and vocabulary errors, neglecting the academic writing style. The revision by a native speaker is highly recommended to increase the quality of the manuscript.
• After making the above detailed modifications, the manuscript is recommended to be published.

Author Response

Dear reviewer,

thank you very much for your comments on the article. In this annex I attach the changes made to the article. All changes made are highlighted in yellow in the text of the revised article. 

Author Response File: Author Response.pdf

Reviewer 2 Report

The quantitative results in the abstract section, makes reader interesting.

Its better to justify the “carbide head is coated with TiAlN coating which increases the auger's life”. Kindly justify with what is the improvement percentage compared with bare carbide head.

Figure 2 captions need to be more clear. There are so many parameters affecting the deep drilling process, how did the author selected few among them. Furthermore, those parameters studied in the present work need to be highlightened in the Figure 2 itself.

The size of chip thickness with change in speed makes more interesting analysis? Kindly let us include authors in the revised version.

Did the authors used replication experiments with different cutting tools for same speed, feed  and so on.

There are many abbreviations reported in the manuscript, kindly expand those terms. Its better to include separate nomenclature and symbols section.

The reason for increasing the feed rate decrease the number of drilled holes need to be explained clearly.

The results are not justified with recent literatures.

The results and discussion need to be substantially improved with valid justification for the results obtained in this work.

The conclusions are to be drawn with bulletin points.

Author Response

Dear reviewer,

thank you very much for your comments on the article. In this annex I attach the changes made to the article. All changes made are highlighted in yellow in the text of the revised article. 

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

The authors considered all the recommendations and made the modifications. The paper is recommended for publishing.

Reviewer 2 Report

Revised strictly according to comments.....