Selected Aspects of Precision Machining on CNC Machine Tools

Round 1

Reviewer 1 Report

The work is novel due to the type of process involved (ultrasonic machining). And although it is true that they use sophisticated equipment and instruments, however, the experimental work is limited and it is not at all clear that to carry out a machining process where the spindle must be preheated for 4 hours since energy is being consumed during all that time, and the machine does not make useful work.

The document also requires the following improvements:

1) It would be necessary to analyze the geometry of the alumina plate before being assembled in the machine and how the assembly could affect its geometry. Maybe by use of finite elements.

2) Every time they present a table in the previous paragraph, they repeat the same data (see tables 1, 2, 3, 4, etc.)

3) The way of presenting the results with a table does not help the reader (table 5). You have to use graphics.

4) What is the value, the contribution of figure 5?

5) In the discussion, every time table 4 is said, it should say table 5.

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

(1) It is suggested that to give a certain background explanation in the abstract, so as to clarify the research content and significance, and provide the contribution and innovation points of the manuscript.

(2) In the “The strategy of machining” part, it is suggested that the reason for adopting this very processing strategy and the reason why is it arranged in this way should be given.

(3) In the manuscript, it is suggested that the research significance and its positive impact on the industry should be emphasized.

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

I consider useful this research to increase the knowledge about aspects of precision machining  on CNC machine tools.

The subject of the manuscript is adequate to the profile of machines journal  

 Please reconsider this “opinion”  in line 49  “ Precision  is basically a session (relationship). If the dimension is from the specified interval, we consider it to be accurate. So accuracy is a human concept.” I consider it essential to distinguish between precision and accuracy as statistical concepts.

In my opinion, the references should be revised and the focus should be on precision machining by ultrasonic machine.

In line 163 the authors said “ We called the experiment as: The spindle temperature influence on topological precision during rotary ultrasonic machining of ceramic material.”  Why isn't that the title of the article? I think it would focus on the research done

In the machine tool subsection, the machine characteristics are stated, which in my opinion is too extensive. However, the precision in the machining ranges supplied by the manufacturer is not expressed. The type of fixture used for the positioning and clamping of the part to be machined is not expressed either.

The methodology of experimentation and the design of experiments should be more clearly defined as it is not clearly specified. ( strategy of machining)

In lines 249 – 253 “ On the second path, the tool axis moved directly above F and again moved along the  interface. The tool circumference "touched" the E interface (on one side) and the right edge  of the workpiece (on the other side). Then the tool went along E and the tool touched D and F. Then it went along D and  the tool touched C and E. And so on. It was worked for about 4 hours and then finished  at place D.”   where is F, E, D, C ?

In line 261, Is the Surfcom 500 roughmeter calibrated and what is the uncertainty?  

Please in figure 3 put an scale

In surface measurements by profile tester what kind of standard and surface parameter do you used?  ISO 4287?  What was the methodology to measure surface?, length of scan, cutt- off, etc  

In table 5, please put the use parameter Ra, Rt ….. The usual standard in surface measurements is to work in microns.

I believe that in the experimental details the parameter Ra/Rt  is used, which is widely used in industry, but in science Sa/St (ISO 25178) is frequently used. Please justify this.

 According  the importance being given to surface finish in precision machining, it would be a future work to study other roughness parameters.

I see this work interesting and positive and I recommend this paper for publication after   revision.

Author Response

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Author Response File: Author Response.pdf

Reviewer 4 Report

The paper deals with the precision of ultrasonic machining.

There are major flaws regarding the content and the presentation of results:

·         Big part of the introduction is not relevant to the topic (e.g. machining errors due to cuting tool static deflections by cutting forces, machining stability etc.)

·         Description of the machining strategy is not clear enough. Illustration is missing

·         What is the tool wear after 4 hour machining process?

·         Information on the slury and its temperature is missing

·         Numbers in mm are nonsense when considering um values

·         What is the measurement resolution of Surfcom 5000?

·         Low quality Fig. 5 and 6, unclear information and questionable interpretation of measured values (Fig. 6: no change of ap??). It is not clear what the measured “profile of interfaces” means

·         Results: heated spindle/tool leads to lower machining errors?? The statement “Heat generation during machining process is necessary” is very strange.

10 authors is extremely a lot, the reason for that is not clear.

Average, please consider careful check of the grammar

Author Response

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Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Good work.

Reviewer 3 Report

I think that the authors have responded appropriately to the recommendations.