Finish machining of hardened gears wheels using cubic boron nitride (CBN) inserts

The paper presents some results of investigation of finish machining of hardened bearing surfaces of cylindrical gear wheels. Finish machining has been performed with wedges of defined geometry made of CBN. The presented investigation results are related mainly to the wear processes of the cutting wedges. Additional results of quality examination of finish machined gear wheels have been presented, too

STEP based Finish Machining CAPP system

This research paper presents various methodologies developed in a STEP based Computer Aided Process Planning (CAPP) system named "Finish Machining – CAPP" (FM-CAPP). It is developed to generate automatic process plans for finish machining prismatic parts. It is designed in a modular fashion consisting of three main modules, namely (i) Feature Recognition module (FRM) (ii) Machining Planning Module (MPM) and (iii) Setup Planning Module (SPM). The FRM Module analyses the geometrical and topological information of the inputted part in STEP AP 203/AP214 formats, and generates a text file with full dimensional details of features and machinable volumes. It is then passed on to the MPM for the selection of best suited machining process. Here, the selection is based on a 7 stage elimination strategy considering major manufacturing factors. After machining planning, the task of selecting the best suited setup is implemented in the SPM module. When these tasks are completed, the system generates the process-planning sheet containing the details of feature, finish cut machinable volume, machining processes with the cutting tool/ media, process parameters and the setup required for machining

Završna obrada zakaljenih zupčanika pomoću kubično borovih nitridnih (KBN) oštrica

The paper presents some results of investigation of finish machining of hardened bearing surfaces of cylindrical gear wheels. Finish machining has been performed with wedges of defined geometry made of CBN. The presented investigation results are related mainly to the wear processes of the cutting wedges. Additional results of quality examination of finish machined gear wheels have been presented, too.Rad prikazuje rezultate istraživanja završne obrade zakaljenih površina cilindričnih zupčanika. Završna obrada se ostvaruje oštricama definirane geometrije izrađene iz KBN. Prikazani rezultati istraživanja odnose se uglavnom na process trošenja reznih oštrica. Dodatno su prikazani rezultati ispitivanja kvalitete obrađene površine zupčanika

Высокоэффективные технологии финишной обработки деталей гидроаппаратуры

Обоснованы технологические возможности повышения эффективности финишной обработки деталей гидроаппаратуры. Даны практические рекомендации.Sound technological opportunities for improving the finish machining of hydraulic equipment. Practical recommendations

Uncertainty Analysis in Laser Deposition Finish Machining Operations

The Laser Aided Manufacturing Process (LAMP) from Missouri S&T is a laser based metals rapid manufacturing process that uses machining to improve the final part\u27s surface finish. When free-form machining, the absence of enough deposited material results in inconsistent scallop heights which result in poor surface finish or incorrect geometry in the final part. This paper investigates a probabilistic approach to various uncertainties involved in the deposition and subsequent machining of an arbitrary part. Furthermore, this paper analyses the machine errors which makes the response of Scallop Height to exceed the predefined maximum scallop height when traveling along the tool path interval distance. Tackling these problems allows us to achieve the final part shape with higher accuracy

Environmental impact comparison of distributed and centralized manufacturing scenarios

Centralized manufacturing and distributed manufacturing are two fundamentally different methods for producing components. This work describes a centralized manufacturing scenario in which parts are produced via forging and finish machining at one central location and are then shipped to the end user. The distributed manufacturing model involves a scenario in which an additive manufacturing process (Electron Beam Melting) is used to produce parts to near net shape with minimal finish machining. Because the process doesn\u27t require molds or dies, production can take place in small production quantities on demand at job shops located close to the end user with little transportation. In other words, parts are not produced until they are needed. This is in stark contrast to the centralized model where large quantities of parts are produced and then distributed at a later date when needed from warehouses. The aim of this thesis is to compare the environmental impact of these two different production approaches under a variety of conditions. The SimaPro software package has been used to model both approaches with input from the user involving part size, amount of finish machining, transportation distances, mode of transportation, production quantities, etc. Results from simulation models indicate that at small production quantities, the environmental impact of forging die production dominates the centralized manufacturing model. As production quantity increases, finish machining begins to dominate the environmental impact. Despite the large transportation distances involved, the transportation distance and mode of transportation actually have relatively little impact on overall environmental impact compared with other factors. Regardless of the production scenario being evaluated, the distributed manufacturing approach had less environmental impact. The production of titanium powder as the raw material contributed the majority of environmental impact for this approach. Although this work examines environmental impact, it does not consider the cost of producing a part. It should be pointed out, however, that the distributed manufacturing approach could someday have a profound effect on supply chain management for replacement parts by reducing or eliminating the need for warehouses along with associated inventory carrying costs, product obsolescence costs, heating and cooling energy, etc

PCPro a Novel Technology for Rapid Prototyping and Rapid Manufacturing

PCPro stands for Precise Cast Prototyping, which is a combination of casting technologies and milling. This method was developed at Fraunhofer IWS in Dresden, Germany. It is patented in Germany [1] and is applied in the USA under US 10/794,936. The main goal for this development was to shorten the process chain for making plastic prototypes accompanied by higher quality. The casting technology was integrated in a machining center in order to enable a high degree of automation and to avoid an external casting system. This means that Rapid Manufacturing can be easily implemented using such an automated combination of casting and machining. This article describes the PCPro method by means of the fabrication of sample parts. The advantages and the limitations in comparison to common Rapid Prototyping and Rapid Manufacturing process chains will be discussed. In addition, the manufacturing of a prototype machine is presented.Mechanical Engineerin

Kinematic Analysis of Rotary Deep-Depth Turning Parameters

This article offers a parameterization procedure for deep-depth turning without simplifying assumptions. In this paper the authors will show comparative results of researching parameters for rotary turning according to the developed methodology and according to the methodology of finish-machining conditions. A theoretically found kinematic coefficient of rotary cutting is presented in the paper

An Integrated Approach to Finish Machining of RP Parts

An integrated approach to finish machining of RP parts and tools has been developed at the University of Rhode Island. Pre-processing operations, including surface offsets to add machining stock, and post-processing operations, including CNC tool-path generation, have been combined into one integrated set of software algorithms to make possible the effective finishing of near-net parts and tools from RP. An in-depth description of the uniquely developed STL vertex offset algorithm will be explored as well as an automatic method for adaptive raster milling, sharp edge contour machining and hole drilling from STL files. The time involved and surface finish benefits of the developed methodology will be compared to alternative approaches.Mechanical Engineerin

The effects of machining process variables and tooling characterisation on the surface generation: modelling, simulation and application promise

The paper presents a novel approach for modelling and simulation of the surface generation in the machining process. The approach, by integrating dynamic cutting force model, regenerative vibration model, machining system response model and tool profile model, models the complex surface generation process. Matlab Simulink is used to interactively perform the simulation in a user-friendly, effective and efficient manner. The effects of machining variables and tooling characteristics on the surface generation are investigated through simulations. CNC turning trials have been carried out to evaluate and validate the approach and simulations presented. The proposed approach contributes to comprehensive and better understanding of the machining system, and is promising for industrial applications with particular reference to the optimisation of the machining process based on the product/component surface functionality requirements