Cutter Diameter Research Articles

Cuttings migration law in the CBM horizontal well

In this study, to explore the CBM cuttings migration law and influence of cuttings parameters and mechanical parameters on it, a CBM drilling horizontal wells visualisation test bench is built using field data. Through the device, cuttings bed transportation test, changing cuttings parameters test and variable mechanical parameters test were carried out. The content was expanded through CFD simulation analysis. The results showed that the cuttings sank to the bottom and formed into a cuttings bed at the connector, and there was a backflow phenomenon. With cuttings diameter and mass increase, the cuttings cleanup became more difficult. Under the best condition of equipment capacity, cuttings, which diameter is less than 5 mm or volume fraction is less than 5%, could be cleaned up. Improving pump delivery can improve transport efficiency, and increasing drilling pipe rotation can improve the cuttings grinding and cuttings migration. [Received: November 18, 2014; Accepted 23 November 2015]

Surface quality in micro milling: Influences of spindle and cutting parameters

Micro milling is a competitive process to manufacture small parts and to structure surfaces in high quality with low set-up costs. However, the micro milling process poses many challenges and basic mechanisms are still to be researched. In addition, process-machine interactions are much more pronounced in micro than in macro machining. In this paper, the influence of the tilt angle of the spindle on the generated surface quality is investigated by kinematic simulations and experiments. Single edge micro end mills with an effective milling cutter diameter of 50μm are applied. Recommendations are given to enhance process stability and surface quality.

Humeral Retroversion in Children with Shoulder Internal Rotation Contractures Secondary to Upper-Trunk Neonatal Brachial Plexus Palsy.

The most common sequela of neonatal brachial plexus palsy is an internal rotation contracture of the shoulder that impairs function and leads to skeletal deformation of the glenohumeral joint. Treatment options include release, transfers, and humeral osteotomy, all ultimately striving for better function through increased external rotation. Prior studies have shown that neonatal brachial plexus palsy alters humeral retroversion but with conflicting findings. We studied retroversion in children with internal rotation contractures from neonatal brachial plexus palsy to clarify its effect on version and surgical planning. Bilateral shoulder and elbow magnetic resonance imaging scans of 21 children with neonatal brachial plexus palsy were retrospectively analyzed. Retroversion referenced to the transepicondylar line at the elbow was measured with respect to 2 different proximal reference axes, the longest diameter of an axial cut of the proximal part of the humerus (the skew axis) and the line perpendicular to the articular surface (the humeral center line). Glenoid version and glenohumeral morphology type (concentric glenoid, posterior-concentric glenoid, biconcave, or pseudoglenoid) were also determined. All geometric variables were assessed for correlation with patient age and the severity of the internal rotation contracture. Retroversion on the involved side was decreased at 6° compared with 19° (p = 0.003), as measured between the skew axis and transepicondylar line. Retroversion referenced to the humeral center line was also decreased at -2° (anteversion) compared with 20° (p < 0.001). Patient age was inversely correlated with retroversion, but was only significant for the skew axis (r = -0.497, p = 0.022), decreasing in linear regression by 2.4° per year (p = 0.038). Humeral retroversion did not correlate with the severity of the internal rotation contracture, glenoid version, or glenoid morphology type. Humeral retroversion is likely to be less on the affected side in children with internal rotation contractures from upper trunk neonatal brachial plexus palsy and merits consideration in surgical planning. Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Upgraded stability analysis of milling operations by means of advanced modeling of tooling system bending

The problem of undesired self-excited chatter vibrations in milling is very common. However, only in the last two decades some significant achievements for the theoretical understanding of this intricate phenomenon have been accomplished. Nevertheless, state of the art dynamic models are still not able to completely explain milling dynamics and chatter onset during some conventional milling operations performed by conventional cutting tools. In this research work, a revolutionary model of tooling system dynamics and of the regenerative effect in milling will be presented. The new model introduces a significant correction to the predicted stability borders when the cutter diameter is relatively large in comparison with tooling system overhang and when curved or inclined cutting edges are applied. Accordingly, the new approach may be of great interest for many industrial applications. The model has been successfully validated by performing experimental modal analysis, cutting force coefficient identification and stability lobes diagram determination, through many specific cutting tests. In the considered case study, where the afore mentioned geometrical features of the tooling system were still moderate, a significant shift of the stability borders of about +25% was experimentally observed and correctly predicted by the new approach.

Influencia de la edad en el crecimiento de vinal (Prosopis ruscifolia Burkart.), en la Provincia de Santiago del Estero, Argentina

El vinal (Prosopis ruscifolia) es un árbol de uso múltiple, constituye bosques halófilos, colonizador por excelencia de ambientes inestables sometidos a inundaciones. El objetivo del trabajo fue analizar las posibilidades de crecimiento de árboles individuales en función de la edad, estimar el tiempo de tránsito y el turno biológico. El estudio fue realizado con 15 individuos de Prosopis ruscifolia ( Mimosaceae), de Loreto, Departamento San Martín, Santiago del Estero, Argentina. La elección de los árboles se efectuó siguiendo los criterios de: árbol dominante, sano, de DAP superior a 15 cm y fuste sin defectos. Para el estudio de crecimiento se trabajó con las secciones transversales obtenidas a las alturas de 0,30, 1,30 m y hasta la primera ramificación. La marcación y medición de anillos se efectuó con el Equipo Computarizado ANIOL y el programa CATRAS, en las orientaciones Norte, Sur, Este y Oeste. Prosopis ruscifolia es una especie de crecimiento rápido en la Región Chaqueña Seca, con anillos de espesor promedio de 5,66 mm (2,20–9,8) con un incremento anual diametral (IA) de 0,93 cm e IMA de 1,075 cm. El diámetro mínimo de corta es de 25 cm, lo que equivale a un árbol de 23 años. El IMA e IA calculado, en volumen de fuste alcanza el turno biológico de corta a la edad de 45 años.Se requiere continuar estudiando el comportamiento de la especie en otras condiciones de crecimiento.

Research on the Relationship between Tool Setting Error and Turning Accuracy

The tool setting error model is put forward in this paper, according to the characteristics of the numerical control lathe tool setting error. On the basis of analyzing the influence factors of tool setting error, the influence of the tool setting error on the part shape error is discussed. Analysis shows that the shape error and size error is produced by the tool setting error, and the error will increase with the diameter size of tool setting error, the cutter diameter, amount of feed and other factors.

English

Melia volkensii is a tree species growing in semi-arid regions of East Africa, and is recognized as one of the most valuable forestry species in such regions of Kenya. The use of root cutting is an easy method for its clonal propagation, but the most appropriate conditions have not been systematically examined. In this study, the relationship between diameter of root cut edge or fresh weight and formation frequency of adventitious bud were assessed. In addition, roots were divided into two fragments, and formation frequency of adventitious bud was compared between cross-sections roots without root tip and roots with root tip. Both the diameter of the cut edge and fresh weight of roots forming adventitious buds were significantly higher than in those not forming them (unpaired t-test, p&lt;0.01). Formation frequency of adventitious bud was 77.0% in roots satisfying the criteria of cut edges diameter &gt;15 mm and fresh weight &gt;20 g, but it decreased (37.2%) in roots that did not meet this criteria. Based on anatomical analysis, an effect of the developmental stage of root fragments on adventitious bud formation was suggested, and root size is thought to reflect the stage of root development. The formation frequency of adventitious buds was 72% even in cross-sectioned roots, and the proportion was not significantly different from that of normal root tip (p&gt;0.05). Therefore, it is concluded that root cutting using cross-sectioned roots are also available for clonal propagation. &nbsp; Key words: Clonal forestry, anatomical analysis of root, availability of cross-sectioned roots.

Balancing of the transversal cutting force for pocket milling cutters: application for roughing a magnesium-rare earth alloy

Removing material efficiently in end milling usually involves taking a width of cut equal to the cutter diameter, i.e., to mill in full slotting as much as possible. However, in this case, end mills are very sensitive to the effects of cutting forces. Cutter deflection and vibrations may become limiting factors, especially at high machining rates and with long overhangs. To overcome these constraints, a new machining method to end mill workpieces can be considered. It is called “balancing of the transversal cutting force” (BotTCF). Indeed, this new machining method allows us to reduce deflection and vibrations and can therefore increase productivity. All the existing studies have used toroidal cutters with round inserts. Hence, the present study will focus on the application of the BotTCF to pocket milling cutters, considering their much more complex geometry. The goal is to determine the optimal inclination of the cutter axis, so as to minimize the transversal cutting force. In order to find this optimal inclination, a new cutting force model has been developed tailored to the pocket milling cutters. Then the BotTCF methodology has been applied to this type of cutter. An experimental validation has been carried out, and results validate the overall approach.

The relationship of fruit size and light condition with number, activity and price of Blastophaga psenes wasp in caprifigs

Coming out of Blastophaga from fruits having higher weight and thicker flesh was higher. Also, Blastophaga wasp needs full light for suitable activity like honey bees. Smyrna and San Pedro figs require pollination (caprification) for fruit set by profichi crop of caprifigs and Blastophaga psenes wasp. The present study, including two experiments, was conducted in Estahban region, Iran. Firstly, characters including number of Blastophaga wasp, fruit weight, ostiole diameter, fruit flesh diameter and cut fruit diameter were evaluated for 36 caprifig genotypes. A high variability was found in the evaluated genotypes, and significant differences were found between them for all of the fruit traits. Blastophaga number exited from fruits having higher weight and thicker flesh was higher than those with lower weight and thinner flesh. Secondly, the effect of different light treatments (0.00, 50 and 100 % light conditions) was studied on the coming out of Blastophaga from fruits of ‘Poozdombali’ caprifig genotype. The highest activity and coming out of Blastophaga wasp was observed at 100 % light. Thus, Blastophaga needs full light for suitable activity like honey bees. Now, the price of a Kg Blastophaga wasp is 10 $ in Estahban market. Thus, fig growers should buy or collect the caprifig fruits with having higher weight and thicker flesh for caprification of edible figs.

Deep Laser-Assisted Lamellar Anterior Keratoplasty With Microkeratome-Cut Grafts.

The goals of this laboratory study were to evaluate the interface quality in laser-assisted lamellar anterior keratoplasty (LALAK) with microkeratome-cut grafts and achieve good graft-host apposition. Simulated LALAK surgeries were performed on 6 pairs of eye-bank corneoscleral discs. Anterior lamellar grafts were precut with microkeratomes. Deep femtosecond (FS) laser cuts were performed on host corneas followed by excimer laser smoothing. Different parameters of FS laser cuts and excimer laser smoothing were tested. Optical coherence tomography was used to measure corneal pachymetry and evaluate graft-host apposition. The interface quality was quantified in a masked fashion using a 5-point scale based on scanning electron microscopy images. Deep FS laser cuts at 226 to 380 μm resulted in visible ridges on the host bed. Excimer laser smoothing with a central ablation depth of 29 μm and saline as a smoothing agent did not adequately reduce ridges (score = 4.0). Deeper excimer laser ablation of 58 μm and Optisol-GS as a smoothing agent smoothed ridges to an acceptable level (score = 2.1). Same sizing of the graft and host cut diameters with an approximately 50-μm deeper host side cut relative to the central graft thickness provided the best graft-host fit. Deep excimer laser ablation with a viscous smoothing agent was needed to remove ridges after deep FS lamellar cuts. The host side cut should be deep enough to accommodate thicker graft peripheral thickness compared with the center. This LALAK design provides smooth lamellar interfaces, moderately thick grafts, and good graft-host fits.

Mini-hydrocyclones applied to the removal of solids from non-Newtonian fluids and analysis of the scale-up effect

In the solids control system, the removal of fine solids from drilling fluid is performed by decanter centrifuges. The use of these centrifuges is limited not only by the costs involved but also by the available space on the oil rig, so they cannot process the entire volume of fluid circulating in the drilling system. This paper proposes the use of hydrocyclones to support decanter centrifuges, aiming to increase the removal rate of fine material from the fluid to be reinjected into the well. To this end, a highly efficient with low flow ratio hydrocyclone geometry was tested, using non-Newtonian fluids with a particulate matter size distribution similar to the conditions encountered in the field. Empirical expressions were obtained to predict the total separation efficiency, flow ratio, capacity and cut diameter of the equipment as a function of the operating conditions. The hydrocyclone scale-up results indicated that the larger device maintains practically the same separation performance as the original device, but provides an evident improvement in processing capacity.

Effect of Coolant Nozzle Sizes on Turning Aluminum Alloy AL319

Background/Objectives: The paper discusses about the optimum cutting parameters with combination of various sizes of nozzle coolant to optimize the surface roughness, chips deformation and dimensional accuracy in the turning process based on the selected setting parameters. The selected cutting parameters for this study were the cutting speed, feed rate, depth of cut and various diameters of nozzle coolant. Methods/Statistical Analysis: Experiments were conducted and investigated based on Design of Experiment (DOE) with Taguchi method. The research of the aggressive turning process on aluminum alloy (A319) for automotive applications is an effort to understand the high speed machining concept, which widely used in a variety of manufacturing industries especially in the automotive industry. Findings: The results show that the dominant failure mode is the surface roughness and dimensional accuracy when the nozzle orifice size increases during machining of the A319. The exploration for dimensional accuracy, productivity and the optimization of cutting speed in the technical and commercial aspects of the manufacturing processes of A319 are discussed in automotive components industries for further work. Applications/Improvements: The result of this study shows that the effectiveness and efficiency of the system can be identified and helps to solve potential problems.

On the diameter of cut polytopes

Given an undirected graph G with node set V and edge set E, the cut polytope CUT(G) is defined as the convex hull of the incidence vectors of the cuts in G. For a given integer k∈{1,2,…,⌊|V|2⌋}, the uniform cut polytope CUT=k(G) is defined as the convex hull of the incidence vectors of the cuts which correspond to a bipartition of the node set into sets with cardinalities k and |V|−k.In this paper, we study the diameter of these two families of polytopes. For a connected graph G, we prove that the diameter of CUT(G) is at most |V|−1, improving on the bound of |E| given by F. Barahona and A.R. Mahjoub. We also give its exact value for trees and complete bipartite graphs. Then, with respect to uniform cut polytopes, we introduce sufficient conditions for adjacency of two vertices in CUT=k(G), we study some particular cases and provide some connections with other partition polytopes from the literature.

Analysis of Micro-Milling of Hardened Tool Steel

The development of industry in the last ten years has caused the production of parts with relatively small dimensions. This has led to intensive development of efficient micro-technologies through research of processes, machines and tools. This paper presents the research of machinability, channels micro-milling in AISI D2 tool steel (X155CrVMo-5), hardened to 62 HRc. As the tool is used micro-milling cutter with diameter of 0.6 mm and relatively large working length of 5 mm. Analysis of surface roughness, burr on workpiece edges and reduction of cutter diameter due tool wear was performed.

Influence of cutter diameter on meshing performance in spiral bevel gears

Playing a critical role in transmitting movement and power, the meshing performance of spiral bevel gears has a significant effect on products’ operational performance. To evaluate the meshing performance, the accurate three-dimensional (3D) spiral bevel gear models are established through the Pro/E and MATLAB softwares, and the finite element analysis (FEA) methods are applied to the theoretical investigation of the influence of cutter diameter on meshing performance in spiral bevel gears. The results obtained show that the cutter diameter has a significant influence on spiral bevel gears’ meshing performance, such as the contact area, contact pressure, bending stress, torsional stiffness and transmission error.

Effect of the size of cuttings (length and diameter) on rooting in cuttings of apple clonal rootstock Merton 793

The study was conducted in net house conditions of fruit Nursery block of Department of Fruit Science, Dr. Y. S. Parmar University of Horticulture and Forestry Nauni, Solan H.P. during 2012-2013 in order to evaluate the effect of size of cuttings (length and diameter) on rooting in cuttings of apple clonal rootstock Merton 793. Cuttings of length (L) viz. 15 cm, 25 cm, 35 cm, 45 cm and diameter ranges (D) viz. 0.75 cm – 1.00 cm, 1.00 cm – 1.25 cm, 1.25 – 1.50 cm were taken. The experiment was laid out in randomized block design (factorial). The cuttings were treated with 2500 ppm IBA (Indole – 3 – butyric acid) as quick dip (10 – 15 seconds) before planting. The results revealed that the cuttings with treatment combination of length (35 cm) and diameter (1.25 cm – 1.50 cm) recorded the highest rooting of cuttings (65 %), number of primary roots (5.00), length of primary roots (28.43 cm), diameter of primary roots (3.25 mm), fresh weight of roots (3.67 g) and dry weight of roots (2.59 g). Hence it is concluded that cuttings of length of 35 cm and diameter of 1.25 cm to 1.50 cm was most suitable for propagation. However, the cuttings of shorter length and diameter, are also able to result in rooting with lower success, therefore, these cuttings would be helpful in case of scarce availability of propagating material.

Effect of a milling cutter diameter on distortion due to the machining of thin wall thin floor components

Effect of a milling cutter diameter on distortion due to the machining of thin wall thin floor components

Manufacturability of Aircraft Winglet for Wind Tunnel Testing

The form, shape and dimensions of the scaled down winglet model become small and thin bringing complexity to manufacturing. The trailing edge tapers to a thickness varying from 0.065mm to 0.099mm along its length. The mounting portion of the winglet is provided with a close tolerance having a slot gap of 5mm and a depth of 35 mm with an angle. Additionally, wind tunnel models require good surface finish on the aerodynamic surfaces and this involves adopting a manufacturing strategy with a control over on the metal cutting parameters to be implemented on a three axes CNC machining centre. The winglet surface is divided into segments in order to handle the cutting forces on the varying aerodynamic cross section. Various metal cutting parameters such as tool path, cutter diameter, feed rate, depth of cut, spindle speed, etc., are evaluated by monitoring segments where the metal cutting is carried out [1] and flow of chips observed. Fixtures and lugs are planned effectively to accommodate the machining of the angular slot in a three axes machining centre itself. Routing of operations to handle the varying thin sections and realisation of the close tolerance slot has enabled a reliable manufacturing approach in an economical way.

Modeling the Complex Impacts of Timber Harvests to Find Optimal Management Regimes for Amazon Tidal Floodplain Forests.

At the Amazon estuary, the oldest logging frontier in the Amazon, no studies have comprehensively explored the potential long-term population and yield consequences of multiple timber harvests over time. Matrix population modeling is one way to simulate long-term impacts of tree harvests, but this approach has often ignored common impacts of tree harvests including incidental damage, changes in post-harvest demography, shifts in the distribution of merchantable trees, and shifts in stand composition. We designed a matrix-based forest management model that incorporates these harvest-related impacts so resulting simulations reflect forest stand dynamics under repeated timber harvests as well as the realities of local smallholder timber management systems. Using a wide range of values for management criteria (e.g., length of cutting cycle, minimum cut diameter), we projected the long-term population dynamics and yields of hundreds of timber management regimes in the Amazon estuary, where small-scale, unmechanized logging is an important economic activity. These results were then compared to find optimal stand-level and species-specific sustainable timber management (STM) regimes using a set of timber yield and population growth indicators. Prospects for STM in Amazonian tidal floodplain forests are better than for many other tropical forests. However, generally high stock recovery rates between harvests are due to the comparatively high projected mean annualized yields from fast-growing species that effectively counterbalance the projected yield declines from other species. For Amazonian tidal floodplain forests, national management guidelines provide neither the highest yields nor the highest sustained population growth for species under management. Our research shows that management guidelines specific to a region’s ecological settings can be further refined to consider differences in species demographic responses to repeated harvests. In principle, such fine-tuned management guidelines could make management more attractive, thus bridging the currently prevalent gap between tropical timber management practice and regulation.

Effect of Cutter Diameters on Surface Roughness Attained in High Speed End Milling of Soda Lime Glass

Soda lime glass is used extensively in camera lens, micro gas turbines, light bulbs, tablewares, optics, and chemical apparatus owing to its high hardness, excellent optical properties, and good corrosion and chemical resistance. Such applications of soda lime glass demand high machining and finishing precision. On the other hand, machining of glass poses significant challenges due to its inherent brittleness. The process of removal of material from glass, if not done in ductile mode, can generate subsurface cracks and brittle fractures which have adverse effects on its functionality. This research investigates the high speed micro-end milling of soda lime glass in order to obtain ductile regime machining. It has been found by other researchers that ductile mode machining can avoid sub-surface cracks and brittle fractures. However, in ductile mode machining, the gummy chips settle permanently on the machined surface affecting adversely the surface finish. In order to avoid such chip settlement, compressed air was directed using a special air delivery nozzle to blow away the resultant gummy chips, thereby preventing them from settling on the machined surface. Response surface methodology (RSM) and a commercial NC end mill were used to design and perform the machining runs, respectively. Machining was done using: high spindle speeds from 30,000 to 50,000 rpm, feed rates from 5 to 15 mm/min, and depth of cuts from 3 to 7 μm. Three different diameter carbide tools were used: 0.5, 1, and 2 mm. A surface profilometer was used to analyze the surface roughness of the resultant machined surface. Subsequently, the data was used for finding the best combination of cutting parameters required to obtain the lowest surface roughness. The results demonstrate that high speed machining is a viable option for obtaining ductile regime machining and generating machined surfaces with very low surface roughness in the range of 0.08μm – 0.22 μm, using 0.5 mm carbide end mill cutter.