Investigation of optimum cutting conditions for STEP-NC turned features
This paper is an attempt to fill a gap in STEP-NC research by proposing a method for determination of cutting parameters based on the parameters of turned features. To achieve this, the equations for cutting parameters were investigated to identify the effects of the variations in the feature parameters on the optimal values of depth of cut and feed. The result of the investigation is a set of data for optimal machining in terms of feature parameters which can be used in machining planning of turned components.
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| owodunni optimum cutting conditions.wmv | 16.62 MB |
Dear Le,
I have pasted the questions below with the corresponding answer.
i)Comment and question No.1:
Use of handbook values are not optimal. A database or knowledge-based approach based on the handbook values only automates this suboptimal solutions.
The generative approach attempts optimality but does so for every case encountered thus being computationally inefficient. Also, it is like a black box and understanding of why the optimal values are obtained is not clear to the user.
The approach in the presentation obtains results that are as optimal as the generative approach but in a parametric way (i.e. dependent on the parameters of the features to be machined). This makes it computationally efficient and also the results on which it is based is more transparent on the general effects of the parameters on the obtained optimal cutting conditions thus giving the user a better feel of reason for the results.
(ii)Comment and question No.2:
The a-s diagram is a grid obtained from range of a and s values such as that from the chip breaker diagram.
The machining cost is a standard expression in machining studies. It is simply a function of the cutting velocity, depth of cut and feed as well as machining constants. Once the specific cost is calculated for each grid point the minimum cost is simply the minimumn of these costs.
(iii)Comment and question No.3:
ISO14649 still requires the cutting conditions at the "how to do2 information level. This feature-based approach suggested in this research enables these cutting conditions to be calculated. This is more important where an intelligent STEP-NC controller is involved. The controller can then automatically generate the optimal cutting conditions.
(iv)Comment and question No.4:
These are experimental values depending on the tool workpiece combinations employed.
Best regards,
Dele Owodunni
Dear Authors,
The presented paper about STEP-NC is very interesting. I have the following questions and comments to you:
(i)Comment and question No.1:
The optimal cutting conditions have been well established in the machining area. There are many programs and database (tool manufactures) which were developed for selecting the optimal cutting condition. The cutting values are calculated based on many variants and by different approaches (handbook, table, intuition, experience and calculation, mathematical models and knowledge-based methods in connection with the database).
What is the advantage of your research about finding the optimal cutting conditions compared to the state-of-the art method?
(ii)Comment and question No.2:
Quality, costs and time depend largely on the cutting conditions. To find the optimal cutting conditions, the objective function needs to be established; it is regarded as ensuring maximum technical and economic efficiency of production obtained by means of manpower, machines and tools available.
My question is how do you construct a-s diagram and how does the minimum cost is calculated based on the feasible points on a-s diagram?.
(iii)Comment and question No.3:
How to apply your research results to ISO14649 (STEP-NC) and STEP-NC controller for the turning machine?
(iv)Comment and question No.4:
The constants bv, cv, bs. cs, br and cr in equations (1), (2) and (3) should be explained in the paper.
Many thanks,
Le, Cardiff University