Small Diameter Drilling Research Articles

Study of Grinding Method of Twist Drills

Twist drill is one of the typical cutting tools, usually used inner conical grinding method to trim and dress .it is presented a method of sharpening twist drills in exterior cone surface grinding wheel. A novel sharpening device of linkage-gear compound mechanism is designed. This device can overcome some limitations that can not grind small-diameter drills in the interior cone surface, hence improves the grinding range and grinding quality.

Creation of Transosseous Patellar Tunnels During Extensor Mechanism Repair

Transosseous patellar tunnels commonly are used in the repair of acute or chronic patellar tendon or quadriceps tendon ruptures. Commonly, a small diameter (2.0-3.5 mm) drill bit is used to create these drill tunnels. However, drill bits are relatively brittle and susceptible to breakage. The use of a larger diameter smooth Steinmann pin (3/32") is recommended to create transosseous patellar tunnels to eliminate this potential complication.

マイクロ・ナノテクスチャを有する小径ドリルを用いたアルミニウム合金の穴あけ加工(機械要素,潤滑,設計,生産加工,生産システムなど)

マイクロ・ナノテクスチャを有する小径ドリルを用いたアルミニウム合金の穴あけ加工(機械要素,潤滑,設計,生産加工,生産システムなど)

Under-ice noise generated from diamond exploration in a Canadian sub-arctic lake and potential impacts on fishes

Mineral exploration is increasing in Canada, particularly in the north where extensive diamond mining and exploration are occurring. This study measured the under-ice noise produced by a variety of anthropogenic sources (drilling rigs, helicopters, aircraft landing and takeoff, ice-road traffic, augers, snowmobiles, and chisels) at a winter-based diamond exploration project on Kennady Lake in the Northwest Territories, Canada to infer the potential impact of noise on fishes in the lake. The root-mean-square noise level measured 5 m from a small diameter drill was approximately 46 dB greater (22 kHz bandwidth) than ambient noise, while the acoustic particle velocity was approximately 40 dB higher than ambient levels. The loudest sounds at the exploration site were produced by ice cracking, both natural and during landing and takeoff of a C130 Hercules aircraft. However, even walking on the snow above the ice raised ambient sound levels by approximately 30 dB. Most of the anthropogenic sounds are likely detectable by fishes with hearing specializations, such as chubs and suckers. Other species without specialized hearing adaptations will detect these sounds only close to the source. The greatest potential impact of noise from diamond exploration is likely to be the masking of sounds for fishes with sensitive hearing.

Osteonecrosis of the Humeral Head

Osteonecrosis of the humeral head is considerably less common than osteonecrosis of the hip. However, as in the hip, the interaction between a genetic predisposition and certain risk factors may lead to increased intraosseous pressure, loss of circulation, and eventual bone death. The most common risk factor remains corticosteroid use, which accounts for most reported cases. Radiographic staging and measurement of lesion size are predictive of disease progression and can be used to determine appropriate intervention. Recent studies have reported the use of various treatment modalities such as pharmacologics, core decompression with small-diameter drilling, arthroscopic-assisted core decompression, and bone grafting. Prospective, randomized studies are needed to determine the efficacy of these joint-preserving procedures. Newer resurfacing techniques have a role in treating articular surface loss. Hemiarthroplasty and total shoulder arthroplasty are recommended for patients with end-stage disease.

Hindlimb Growth after a Transphyseal Reconstruction of the Anterior Cruciate Ligament

Background There is a lot of controversy in the recent literature with regard to the optimal treatment of anterior cruciate ligament (ACL) injuries during growth. Iatrogenic growth disturbance due to physeal damage is a potential complication, forcing many orthopaedic surgeons to treat these injuries conservatively. Hypothesis It is possible to perform a fully transphyseal ACL reconstruction in an ovine model with wide-open physes without creating growth disturbances. Study Design Descriptive laboratory study. Materials and Methods Four-month-old skeletally immature sheep underwent a transphyseal ACL reconstruction of the right knee. The surgical technique followed the criteria known to be essential to avoid growth disturbances in humans; the tibial tuberosity was spared to prevent a genu recurvatum, thermal damage to the growth plates was avoided, the physes were perforated with a small-diameter drill in the center of the growth plate, a soft tissue graft was used, graft fixation was achieved far away from the growth plates, the perforated growth plates were filled by the soft tissue graft, and the graft was moderately pretensioned before fixation. The left knee served as a control. A computer-assisted evaluation of long radiographs (frontal and sagittal plane) of the exarticulated hindlimbs was performed to exactly evaluate the limb alignment, joint orientation, and leg length. The animals were sacrificed in groups of 6 after 3, 6, 12, and 24 weeks. Results No angular deformities or leg-length discrepancies occurred after this transphyseal ACL reconstruction procedure throughout the remaining growth. Conclusion This large-animal study supports the clinical observation that it is possible to perform an ACL reconstruction without creating growth disturbances as long as a number of key principles are followed. Clinical Relevance Previous animal studies argued against ACL reconstruction in skeletally immature patients. This large-animal study provides support for early operative treatment of ACL ruptures even in young patients with open physes.

Design and tuning of a fuzzy logic controller for micro-hole electrical discharge machining

The design and tuning of a three-input fuzzy logic controller for electrical discharge machining (EDM) of diesel injector spray holes are presented. The tuning process is based on the variable type and discretization level to balance the data precision and computational time for servo motion updates in the fuzzy logic controller and is performed to improve the micro-hole EDM drilling time. The type and number of input parameters are studied to select the gap voltage, spark ratio, and change of spark ratio as input parameters for the fuzzy logic controller. A gain scheduling controller is used as the baseline and shows excellent drilling time in drilling a 1.14 mm thick workpiece using a 150 μm diameter wire electrode. The tuned fuzzy logic controller is comparable with the gain scheduling controller in drilling time and demonstrates its advantages on different EDM drilling configurations, including deep-hole and small-diameter micro-hole drilling. Analysis of EDM pulse trains reveals insights for controller design and identifies requirements for further improvement.

Do Modern Techniques Improve Core Decompression Outcomes for Hip Osteonecrosis?

Core decompression procedures have been used in osteonecrosis of the femoral head to attempt to delay the joint destruction that may necessitate hip arthroplasty. The efficacy of core decompressions has been variable with many variations of technique described. To determine whether the efficacy of this procedure has improved during the last 15 years using modern techniques, we compared recently reported radiographic and clinical success rates to results of surgeries performed before 1992. Additionally, we evaluated the outcomes of our cohort of 52 patients (79 hips) who were treated with multiple small-diameter drillings. There was a decrease in the proportion of patients undergoing additional surgeries and an increase in radiographic success when comparing pre-1992 results to patients treated in the last 15 years. However, there were fewer Stage III hips in the more recent reports, suggesting that patient selection was an important reason for this improvement. The results of the small-diameter drilling cohort were similar to other recent reports. Patients who had small lesions and were Ficat Stage I had the best results with 79% showing no radiographic progression. Our study confirms core decompression is a safe and effective procedure for treating early stage femoral head osteonecrosis.

Surgical and Molecular Advances in Osteonecrosis: Editorial Comment

Surgical and Molecular Advances in Osteonecrosis: Editorial Comment

Mechatronical system for testing small diameter drills

This paper describes a technique and mechatronical system for testing drills of a small diameter at different stages of production. The goal is to realize a system for drill testing which automatically increases the load applied to a drill under testing conditions and measure the drill's breaking torsion moment and deflection angle before a break occurs. The system's apparatus part and algorithms for the control of actuators and data acquisition from sensors are explained in the article. Also, a testing technique was applied in theoretical investigations to define the stress concentrations in dangerous places of the drill. The proposed technique and system have been verified by testing the drills of a small diameter at different stages of production—after thermal, mechanical treatment, and for quality control of the finished product.

Water separator shows potential for reducing respirable dust generated on small-diameter rotary blasthole drills

Drilling with water has the potential to significantly reduce the respirable dust concentrations generated from small-diameter rotary drills when drilling blastholes on surface mining operations. However, water adversely affects tri-cone drill bits commonly used in surface drilling operations, causing excessive wear and premature replacement. Consequently, dry drilling with a dust collector system has the most widespread use in the industry. Tests have been conducted by the National Institute of Occupational Safety and Health (NIOSH), Pittsburgh Research Laboratory (PRL) on a newly designed device for smaller diameter drills that separates the water from the bailing air before it reaches the bit and thus provides the cost benefit of dry drilling while providing the benefit of wet drilling for dust suppression. The water that is delivered to the hole with the bailing air is separated from the air by a proprietary mechanical device that is encased in a drill sub (short section of drill rod/pipe) located immediately behind the cutting bit. A cascade cyclone and a real-time dust monitor were used to sample dust emissions from the holes. Dust concentrations and silica content were measured when drilling dry versus drilling wet. The tests show that drilling with this water separating sub can reduce both measured dust emissions from the boreholes and visible dust around the drill rig.

Clinical evaluation of small diameter decompression and arthroscopy in the treatment of early avascular necrosis of femoral head

To investigate the therapeutic effect of small diameter, multiple porous, low drill velocity decompression and hip arthroscopy in treatment of early avascular necrosis of femoral head (ANFH). 226 ANFH patients (383 hips), 169 males (296 hips) and 57 females (87 hips), aged 36.5 (14 - 64), underwent drilling decompression with 3.5 mm Steinmann pin at a low velocity under the C-arm X-ray monitoring, all the 383 hips were decompressed with Steinmann pin, small diameter, multiple porous, low drill velocity. Synovectomy and cartilage trimming were performed through hip arthroscopy at the same time on the 209 hips combined with hip arthrosynovitis or cartilage trauma. 164 cases were followed up for 35 months (3 - 60 months). The Harris score was increased from 68 (56 - 78) pre-operatively to 79 (58 - 92) post-operatively. Excellent curative effect was found in 198 of the 383 hips (69.5%) with a Harris score > 80, medium curative effect was found in 70 hips (24.5%) with a Harris score between 70 and 79; and bad effect found in 17 hips (6.0%) with a Harris score < 69. During the follow-up, these 17 hips presented progress in staging of clinical course and collapse of femoral head. 139 hips with hydrops articuli were treated with arthroscopy, and 87 of the 139 hips underwent hip MRI during the follow-up. It was found that the hydrops articuli decreased in 59 hips and increased in 10 hips. Complications were found in 10 cases and all of them were recovered after treatment. The effect of small diameter, multiple porous and low drill velocity decompression is equal to or surpasses traditional core decompression. Small diameter decompression has the advantage of less osseous destruction of femoral head, delaying femoral head collapse and improving blood circulation in the necrosis zone of femoral head. Hip arthroscopy can greatly improve the therapeutic effect of ANFH through scavenging pain-producing substance, removing the cartilage chips caused by isolation or undermining dissection, and correcting internal environment disorder.

Overview: Offshore Drilling and Completion (April 2007)

Just flying over the North Sea, from Stavanger to Aberdeen, is definitely an interesting time to contemplate what the future of offshore drilling could be. Not that long ago, this so-called mature region was seen as declining, and drilling activity was slowly decreasing. In recent months, anyone trying to find an available offshore rig there (as in many other places indeed) knows that this vision of decline must be put aside, and for a long time, he/she will be very cautious with a prognosis about the future. One thing that probably will remain is the pressure on drilling engineers and drilling teams as a whole to control, or at least mitigate, well costs. Several methods can be envisaged, which might be very different. Of course, the market could be the first mitigating agent when a new equilibrium point will be reached. But does this industry really function on equilibrium points? And, for instance, is there any ceiling or minimum for deep-offshore-rig rates? A first means could be to increase pressure on rig efficiency. We have been continuously and successfully improving technology, rig automation, and rig-time management for years. Still, there certainly is room for such improvements, and maybe a stopwatch will be the first driller's tool. Another means is, of course, based on reducing our needs to the minimum. Even though this method has not always (or not yet) been successful from a business point of view (for instance, the slender-well concept), there are still interesting concepts that someday could introduce real breakthroughs. Some "drilling-from-the-mudline" concepts are probably among them, and the current mood for small-diameter drilling could be part of their success. Eventually, beyond these cost challenges, new technical challenges also will have to be addressed. Our desire for fossil fuels will lead us to envisage producing such difficult reservoirs that, today, are often produced only onshore (e.g., heavy oils, tight reservoirs, and smaller accumulations). These challenges might once more put pressure on well costs so that, in the end, we may still be running after market equilibrium for a long time. Offshore Drilling and Completion additional reading available at the SPE eLibrary: www.spe.org SPE 101080 "Design and Performance Evaluation of an Ultradeepwater Subsea Blowout-Preventor Control System Using Shape-Memory Alloy Actuators" by N. Ma, U. of Houston, et al. SPE 98894 "Large-Scale Feasibility Determination of Storing and Transporting a Cement Slurry Below Deck Under Maritime Conditions" by D. Doherty, SPE, BJ Services, et al. SPE 99005 "First Hyperstatic Riser Joint Field Tested for Deep Offshore Drilling" by Y. Poirette, SPE, Inst. Français du Pétrole, et al. SPE 105649 "CIDS to Orlan: Transformation and Startup of Sakhalin's Ice-Resistant Drilling Platform" by A.M. Higgins, SPE, ExxonMobil Development Co., et al.

253 スーパーエンジニアリングプラスチック板材への小径深穴加工の実施(OS6-1 加工技術の進展)

253 スーパーエンジニアリングプラスチック板材への小径深穴加工の実施(OS6-1 加工技術の進展)

Modeling of small-diameter rotary drilling tests on marbles

In this paper, continuum mechanics and discrete modeling are applied to investigate numerically rotary drill cutting experimental results on four marbles. Rock-cutting tests were performed by a new portable rotary microdrilling tool currently employed in practice for the quasi-non-destructive characterization of strength properties of rocks. The objectives of this research work are twofold, namely: (a) to gain insight in the cutting mechanism of cohesive-frictional rocks, and (b) to examine the comparability of numerical models predictions with experimental results by solving the forward problem. In the first type of model, a plane strain continuum calculation is done with a non-hardening, elastic–plastic, linear Mohr–Coulomb model with non-associative flow rule. In the second type of numerical model, discrete element calculations are done on a simulated plane strain sample of 540 discs. In both models, estimations are made on components of force applied to the cutting face of the bit and are compared with measurements taken with the data-acquisition system of the portable microdrilling tool during specially designed tests on marbles. It is found that the predictions of the continuum model are in full accordance with measured forces during drilling. It is also shown that the cohesion and internal friction angle are the most important parameters affecting the rock drilling resistance, as is depicted by the limit analysis theory of plasticity. Moreover, the calibration of the discrete element model on the experimental data permits the approximate estimation of the mode-I fracture toughness for each type of marble.

403 小径ドリルによる軟鋼板への穴あけ : 穴形状の評価法と形状精度に影響する因子の解明(加工技術の高度化(1))

403 小径ドリルによる軟鋼板への穴あけ : 穴形状の評価法と形状精度に影響する因子の解明(加工技術の高度化(1))

Control of Drilling Condition at a Small Diameter Drill (1st Report, Controllability and Observability of Drill Edge Position)

Control of Drilling Condition at a Small Diameter Drill (1st Report, Controllability and Observability of Drill Edge Position)

Factor Analysis on Internal Damage around Small Daimeter Drilled Hole of GFRP Printed Wiring Boards by Data Mining Method

Recently, a demand of miniaturization and performance enhancement of the printed wiring board is intensified more and more with the rapid popularization of the information terminal electronic equipment. The processing by the micro drill is generally used in small diameter drilling of the printed wiring board made of GFRP. Then, the through-holes of small diameter are desired for the miniaturization of the equipment. There is an internal damage of micro drilled hole in one of the problems in the formation of the through-hole in the micro drilling. The purpose of this report is to apply a data mining method (that is the method of statistically analyzing the factors) to the image processing data of micro drilled holes, and to elucidate the factors which influences internal damage generalizing. Following conclusions were obtained : (1) It is clear that the internal damage depends on three factors (the thickness of fiber bundle drilling hole wall side, the feed rate and the width of reverse fiber bundle). (2) We can indicate a practical formula to predict the internal damage width around the micro drilled hole by a data mining method.

赤外線サーモグラフィによるプリント基板のマイクロドリル加工現象のモニター −アラミド繊維強化基板の加工時のドリル温度について−

In the current manufacture of multi-layer printed wiring boards, AFRP (Aramid Fiber Reinforced Plastices) has been attracted attention, because of its low coefficient of linear thermal expansion in the x-y plane and of good machinability of CO2 laser. However, there are few reports dealing with drilling of AFRP printed wiring boards. Therefore, this paper describes the small diameter drilling of AFRP printed wiring boards. First, the temperature of drill tools was monitored by infrared thermography. Second, the drilled hole walls were observed by SEM and optical microscope. Comparing with them, it is clear that the drilled hole quality depend on the drill tool temperature in drilling. Additionally, it is confirmed that the increase of drill temperature is due to the heat caused by friction between the drill tool and drilled hole wall.

Predicting the specific energy of autogenous and semi-autogenous mills from small diameter drill core samples

A rock breakage test has been developed that can help predict autogenous (AG) and semi-autogenous (SAG) mill performance in situations where only limited quantities of rock samples are available. The test was originally developed to make use of quartered (slivered) core but whole core, half core and lump material can also be used. Original core diameters in the range 27–85 mm are suitable. The samples, once broken, can be used subsequently for Bond ball mill work index or batch grinding tests, therefore limiting overall sample requirements. The test generates an index (DW i ) that can be used to estimate the throughput of AG and SAG circuits through a combination of power-based and model-based approaches. The model-based approach makes use of the direct relationship between the DW i and the JK rock breakage parameters A and b. The power-based route uses correlations which have been developed between the DW i and the specific energies of a very wide range of operating AG and SAG circuits. Its usefulness also extends to rock mass characterisation in mining applications, as it is also correlated with the point load index/UCS. It is therefore ideally suited for mine-to-mill studies where it can be simultaneously used to predict comminution circuit performance and to augment input to blast fragmentation models. This makes it a useful tool for orebody profiling in greenfield, brownfield and established operations as, in conjunction with a mine’s block model, a detailed picture can built of the blast fragmentation and comminution circuit response.