A New Method for Cutting Tools Design

Author(s):  
Nicolae Oancea ◽  
Victor G. Oancea ◽  
Epureanu Alexandru

Abstract Most of the existing methods for determining the profiles of cutting tools that work by wrapping are based on the envelope theory. This theory requires cumbersome analytical formulations resulting in sets of equations not always easy to solve. This work presents a new alternative method for studying conjugated surfaces associated with rolling axodes by using a discrete representation of the tool. The new method is based on studying the trajectories of points on the tool relative to the workpiece in order to define the tool’s profile. Several examples are shown for rack, shaper and rotational cutters.

Author(s):  
Nicolae Oancea ◽  
Victor G. Oancea

Abstract Most of the existing methods for determining the profiles of cutting tools that work by wrapping are based on the envelope theory which requires cumbersome analytical formulations associated with the solution of equations not always easy to resolve. This work presents a new alternative method for studying conjugated surfaces associated with rolling axodes. The original meshing surfaces are replaced by a family of curves of substitution which gives a simpler interpretation of the envelope theory. The meshing line and the contact points can be easily determined. An equidistant to the tool profile can be simply calculated which can be very useful in the case of machining with cylindrical abrasive disks. Several examples are shown for rack, shaper and rotational cutters.


1997 ◽  
Vol 119 (4B) ◽  
pp. 829-834 ◽  
Author(s):  
N. Oancea ◽  
V. G. Oancea

A number of methods exist for determining profiles of cutting tools that work by wrapping. Most of these methods are based on the envelope theory and almost inevitably require cumbersome analytical formulations not always easy to resolve. This work presents a new method for studying conjugated surfaces associated with rolling axodes. Originally devised in an analytical form in a previous work of the first author, a purely numerical method is developed here based on a theorem which we call “the theorem of the minimal distance.” The advantage is twofold: first, geometrical modeling of tool profile calculation is possible even for profiles which cannot be described analytically; second, a very useful tool is provided for the inverse problem—starting from the measured cutting edges profiles, one can calculate the effectively generated surface on the workpiece. Several examples are shown for rack, shaper, and rotational cutters.


2007 ◽  
Vol 16 (1) ◽  
pp. 101-111 ◽  
Author(s):  
Kenneth Benoit ◽  
Michael Laver

In “A Robust Transformation Procedure,” Martin and Vanberg (2007, hereafter MV) propose a new method for rescaling the raw virgin text scores produced by the “Wordscores” procedure of Laver, Benoit, and Garry (2003, hereafter LBG). Their alternative method addresses two deficiencies they argue exist with the transformation of virgin text scores proposed by LBG: First, that the LBG transformation is sensitive to the selection of virgin texts, and second, that it distorts the reference metric by failing to recover the original reference scores when reference texts are scored and transformed as if they were virgin texts. Their proposed alternative is “robust” in the sense that it avoids both shortcomings. Not only is MV's transformation a welcome contribution to the Wordscores project but also the critical analysis on which it is based brings to light a number of assumptions and choices that face the analyst seeking to estimate actors' policy positions using statistical analyses of the texts they generate. When first describing the possibility of rescaling the raw virgin text estimates, we emphasized that ourparticular approach to rescaling is not fundamental to our word-scoring technique but, rather, is a matter of substantive research design unrelated to the validity of the raw virgin text scores… Other transformations are of course possible. (LBG, 316)To explore more fully into the assumptions and choices behind alternative transformations and the research designs which motivate them, we offer the following comments.


Author(s):  
Edgar A. Mendoza López ◽  
Hugo I. Medellín Castillo ◽  
Dirk F. de Lange ◽  
Theo Lim

The CNC machining has been one of the most recurrent processes used for finishing NNS components. This paper presents a new method for the generation of tool paths for machining 3D NNS models. The proposed approach comprises two machining stages: rough cut and finish cut, and three types of cutting tools: ball-end mill, flat-end mill and fillet-end mill. The proposed tool path generation algorithm is based on: (1) approximation of the model surfaces by points using slice planes and visibility analysis, (2) accessibility analysis of the tool, (3) approximation error and tolerance evaluation, (4) collision analysis of tool and tool holder. The tools paths generated are exported as a CNC program. The implementation was carried out in C++ using the ACIS® geometric modeling kernel to support the required geometric operations. To prove the effectiveness of the system several models with variable geometric complexity were tested. The results have shown that the proposed system is effective and therefore can be used to generate the tool paths required for finishing 3D NNS components.


1982 ◽  
Vol 49 (2) ◽  
pp. 209-219 ◽  
Author(s):  
Allan J. Cliffe ◽  
Barry A. Law

SUMMARYOptimum conditions have been determined for the use of Hide Powder Azure (HPA) to estimate extracellular proteinases produced by psychrotrophic Gram-negative bacteria. This assay is quicker, more precise and 3·2 times more sensitive than assays of soluble N released from casein. It provides a simple alternative method for monitoring proteinase purification schemes. With the modification described it is now possible to determine proteinase activities directly in milk. In its simplest form the HPA assay is sufficiently sensitive to detect proteinases produced by as few as 1·5 x 106 c.f.u. ml-1 psychrobtrophs without the necessity for any sample processing.


Author(s):  
Charles Kim

In this paper a new method for the synthesis of compliant mechanism topologies is presented which involves the decomposition of motion requirements into more easily solved sub-problems. The decomposition strategies are presented and demonstrated for both single input-single output (SISO) and dual input-single output (DISO) planar compliant mechanisms. The methodology makes use of the single point synthesis (SPS) which effectively generates topologies which satisfy motion requirements at one point by assembling compliant building blocks. The SPS utilizes compliance and stiffness ellipsoids to characterize building blocks and to combine them in an intelligent manner. Both the SISO and DISO problems are decomposed into sub-problems which may be addressed by the SPS. The decomposition strategies are demonstrated with illustrative example problems. This paper presents an alternative method for the synthesis of compliant mechanisms which augments designer insight.


2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Devon Gidley

PurposeThis paper develops a new method to study institutions based on institutional work theory. Institutional disruption is intentionally utilized to explore the taken-for-granted foundations of social institutions. The paper outlines the method and considerations.Design/methodology/approachTaking inspiration from ethnomethodological breaches, the paper outlines the steps in the new method called researcher initiated institutional disruption (RIID). The four steps are identifying the institution, identifying the institutional actors, selecting the disruption type and disrupting the institution to gather data (action and reaction). RIID utilizes three types of institutional disruption: undermining assumptions and beliefs, resistance and issue raising.FindingsThe new method complements traditional field methods, such as observation, by showing how a researcher can deliberately make taken-for-granted institutional features visible. The paper finds that RIID offers the opportunity to gather different data, but it is not appropriate for every study and carries potential consequences in the field.Originality/valueThis paper contributes to the literature by outlining an innovative use of theory as method. The approach has not previously been detailed and offers the potential to access previously inaccessible research questions, data and theoretical insights.


2012 ◽  
Vol 11 (3) ◽  
pp. 174
Author(s):  
Siti Sarah Aulia Amrullah ◽  
Rosida Sani ◽  
Nurfadhilah Arifin ◽  
Muhammad Ruslin

Augmentation of the alveolar ridge is widely performed in implant treatment to create predictable function andesthetics in area with inadequate bone volume. There are some different ways to augment the alveolar ridge.Distraction osteogenesis is a new method in increasing the width of the ridge and preparing a sufficient bed for implantor prosthesis. Distraction osteogenesis result in formation of new bone between bone segments that are separatedgradually by incremental traction. Alveolar widening by distraction osteogenesis is an alternative method forreconstructing alveolar atrophy that is similar to alveolar split grafting but without grafting, which offers manyadvantages over traditional techniques. This paper is aimed to discuss considerations and technique of alveolar ridgeaugmentation for preparing adequate bone volume before applying implant by using distraction osteogenesistechnique.


2015 ◽  
Vol 71 (1) ◽  
pp. 76-81
Author(s):  
J. Brosius

This paper presents a completely new method for the calculation of expectations (and thus joint probability distributions) of structure factors or phase invariants. As an example, a first approximation of the expectation of the triplet invariant (up to a constant) is given and acomplexnumber is obtained. Instead of considering the atomic vector positions or reciprocal vectors as the fundamental random variables, the method samples over all functions (distributions) with a given number of atoms and given Patterson function. The aim of this paper was to explore the feasibility of the method, so the easiest problem was chosen: the calculation of the expectation value of the triplet invariant inP1. Calculation of the jointprobabilitydistribution of the triplet is not performed here but will be done in the future.


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