Dr. Fleischfresser,

After a review of your revised document submitted in response to the reviewers comments, we have decided to accept your article for publication in the Journal of Open Engineering.

Thank you for your contribution!

Devin Berg

Editor, TJOE

The text of first item is now part of the introduction. Corrected link on item 3 above (a "1" is missing at the end): https://doi.org/10.6084/m9.figshare.3840429.v1 Captions for figures 1a and 1b should now be compliant.

Thank your for your response. Could you perhaps address the first item in your introduction. Incorporating the argument of your response here should be sufficient.

Corrected link: https://nuvem.utfpr.edu.br/index.php/s/CMUBxzy8fE3yMt2

REVIEW FOR THE JOURNAL OF OPEN ENGINEERING The manuscript presents an kinematics analysis of a mechanism denoted by two slender bars with a design revolution. This mechanism is a typical four-bar linkage analyzed in a wide variety of books and papers about mechanism and dynamics of machinery. Numerical simulations are performed to compare two different configurations. TECHNICAL SOUNDNESS Technical formulation seems to be correct. However, an approach using generalized coordinates or dimensionless variables might be more interesting. Some typos can be found in the paper: - vector notation: omega, V_A, V_B, ,rho_OA, rho_CB, rho_BA,.... - units in mathematical mode CLARITY It is not clear the main contribution of the manuscript: the kinematic analysis or numeric simulations? In spite of technically correct formulation of the kinematics equations, the notation and abbreviations used makes it difficult to read. It might be preferable to use throughout the manuscript the notation sin(alpha) instead l, cos(alpha) instead, and so on. It is not clear why the kinematic analysis was separated in original mechanism and modified mechanism. That seems the original mechanism is a particular configuration of the modified mechanism. Author does not explain why they employed the constant rotation w= 2 rad/s and the variable rotation w = 0,1+2,3alpha rad/s for the kinematics analysis. The selected simulated rotation constitute two really simple examples to evaluate the mechanism. It would be more appropriate to use more complex simulations. For instance, harmonic and exponential rotation. COMPLETENESS The state-of-the-art section is weak. Taking a look at the literature, it can check that there are many works about kinematics and kinetics analysis of four-bar mechanisms. The citations section is incomplete, no reference has date.

REVIEW FOR THE JOURNAL OF OPEN ENGINEERING In this paper the author derives the kinematic equations governing the four bar linkage, a common dynamics benchmark problem. The author then compares different linkage lengths and two driver input angular velocities by numerically evaluating the equations. This article is something that may belong well in an introduction to kinematics course notes, but does not really belong in a modern technical journal. The four bar linkage is one of the most common and widely studied linkages there are. There are many thousands and thousands of derivations of this out in the wild. It isn't clear to me that this derivation offers anything new to this classic problem. At the end of the article the author states "This work was motivated by the desire to introduce project-based activities in the undergraduate engineering mechanics’ classroom." This article could possibly be framed in this light and offer something useful to the journal's audience. Maybe this derivation method is an exceptional way to enlighten students and that would be worth telling a story about. But as it stands this article doesn't have a story worth telling in this journal. TECHNICAL SOUNDNESS I think this article is likely technically sound. If the author compared his results with other benchmark results of the four bar linkage then we could feel fully confident of the soundness. CLARITY The writing is fine but doesn't use common nomenclature and descriptions for kinematics. For example, it is odd that the author never mentions the phrase "four bar linkage". The introduction cites a number of frivolous references that do not seem related to the article in any substantial way. COMPLETENESS This is fine. OPENNESS AND REPRODUCIBILITY This article over presents the derivation of this common problem, which is good for reproducibility but simply showing the final kinematic equations would be more than sufficient. The author evaluates the equations numerically and it isn't apparent if software was used to do this. If it was used, there is no code or data artifact cited.

One additional comment. It is not acceptable to use copyrighted figures from a textbook in this venue.