Workshop Practice Research Articles

A study of the influence of steam treatment on the tribological behaviour of steel specimens

The influence of steam treatment (ST) on the tribological behaviour of steel was assessed by Falex, Schwingungsreibverschleiss (SRV) and Amsler tests performed either under dry conditions or using solid MoS 2, graphite, polytetrafluoroethylene (PTFE) or grease lubricants. ST produced a thin layer of magnetite containing small quantities of haematite. MoS 2 was found to be the best lubricant in Falex tests with normal test pieces. Only greaselubricated Amsler couples withstood the full testing cycle. The SRV tests were inconclusive because the endurance time was too short, only a few seconds with MoS 2 lubrication. The influence of ST varied in the Falex tests. No improvement was found with grease-lubricated journals and the load-carrying capacity of MoS 2-lubricated test pieces was decreased. However, it was beneficial for PTFE lubrication. In the Amsler tests the grease-lubricated disks were crazed and magnetite splinters were removed. The performance of the graphite lubricant was lowered by ST and the median lives of MoS 2- or PTFE-lubricated couples were increased although their reliability was impaired. In SRV tests, ST improved the performance of grease and MoS 2-lubricated test pieces. The test results do not confirm the reported improved behaviour of ST components, particularly cutting tools, in workshop practice.

Middle Byzantine Churches of Kastoria: Dates and Implications

The article proposes the following chronology for the Middle Byzantine chapels of Kastoria in northern Greece through an analysis of their formal architectural characteristics and construction materials in conjunction with a consideration of surviving fresco decoration: H. Stephanos, the Taxiarchs, and the Koubelidiki, late 9th or early 10th century; the Anargyroi, first half of the 11th century; and H. Nikolaos tou Kasnitzē, third quarter of the 12th century. The implications of this chronology for the understanding of Byzantine workshop practices, patronage patterns, and Macedonian history are also discussed. The appendix deals with the more problematic redating — from the 13th century to the late 11th or early 12th century — of the frescoes of the Mavriotissa Monastery located just outside Kastoria.

The application of safety teaching to practical work in further education establishments: With reference to basic engineering training courses

Approximately 10,000 students attend full-time basic engineering training courses in further education establishments in Great Britain. A study of the teaching of safety was made in respect of engineering workshop practice classes in order to explore whether the practical significance of classroom teaching was adequately demonstrated to students at a personal level; whether safety was taught in a positive way particularly in connection with skills which students would use in industry; and to show how safety teaching in engineering workshop practice classes might be improved. Strong evidence of inadequacy in safety teaching was found in the responses of 360 students in eleven establishments to a questionnaire/checklist on workshop procedures. Scores were awarded for ‘safe/unsafe’ responses to items dealing with five categories of workshop procedures which are generally recognised as good safety practice. The scores revealed highly significant differences in the several groups of students that were tested. The differences pointed to variations in the teaching of the lecturers concerned. The overall findings from the study suggested that safety teaching would be improved if (a) the safety knowledge of lecturers was improved and (b) if further education establishments insisted on positive application by workshop lecturers of the safety taught in the classroom.

Reviews : English in Workshop Practice (1975) Alan Mountford

Reviews : English in Workshop Practice (1975) Alan Mountford

Optical Dispensing and Workshop Practice

Optical Dispensing and Workshop Practice

High Speed Trains Necessitate Improved Quality Control of Metal Pretreatment

The advent of the new generation of high speed trains has necessitated a review of the quality of control of painting practices. Factors influencing this are change in construction of rolling stock and increased susceptibility to impact damage due to higher running speeds. To meet the high standard required it has been necessary to critically examine initial surface preparation of the steel, the phospating process and the painting process. Modern trends in workshop practice have led to more frequent repainting of stock. The effects of variable surface preparation and the overstressing of multi-coal oxidizing paint films on the critical balance between substrate adhesion and stress development are also considered.

The incidence of the hypothenar hammer syndrome.

Occlusion of the superficial palmar branch of the ulnar artery amongst workers in mechanical workshops is related to the use of the hand as a hammer. Of 79 habitual hammerers, 11 (14%) showed evidence of ulnar artery occlusion in one or both hands. Those suffering from the hypothenar hammer syndrome were found to be older and to have had longer employment in hammering jobs, than those who used their hands as hammers but had intact ulnar arteries. Symptoms of vascular insufficiency were universal among those with blocked ulnar arteries. It should be possible to prevent the lesion from occurring by insistence on good workshop practice.

Films

The Central Film Library has recently published new 1968–69 editions of its ‘Main Catalogue,’ price 6s (post free), and its ‘Films for Industry Catalogue,’ price 4s 6d (post free). Both are indispensible works of reference for all serious users of film in the fields of teaching, technology and trade — whether they be managers, operatives or trainees or whether their interest lies in aircraft or arts, ceramics or ceremonial occasions, sports or safety, workshop practice or war. The ‘Films for Industry Catalogue’ has one very interesting innovation; it now lists a number of films produced by BBC Television within the last couple of years. Six series of those black and white tele‐recordings may be of particular interest to readers of Technical Education and Industrial Training.

Lens Making for Scientific Instrumentation in the Seventeenth Century

With the invention of the telescope and the microscope early in the 17th century, the production of optical lenses became an important factor in the development of these instruments for scientific observation and investigation. In spite of improvements in equipment and techniques, the obstacles to the production of suitable lenses were not surmounted until the 18th century because of lack of knowledge of the optical properties of lenses, and the difficulties in producing glass of suitable clarity due to primitive grinding and polishing techniques. The early astronomical lenses were produced by means of the primitive equipment of the mirror makers and polishers of pietre dure in Murano and Venice. The first professional apparatus for lens grinding and polishing was developed by Ippolito Francini of Florence, and subsequently improved by Eustachio Divini and Carlo Antonio Manzini. A major advance in the equipment and techniques was made by Giuseppe Campani of Rome in the second half of the century. Other important contributions were made by Christiaan Huygens in Holland and John Marshall in England. Toward the end of the 17th century, craftsmen in England and France made great strides in the improvement of apparatus and techniques for lens grinding and polishing. In spite of them, however, optical workshop practice improved extremely slowly, and it remained virtually unchanged into the 19th century.

THEORY OF CIRCULAR SAW TENSIONING

SUMMARY A hammer having a face in the shape of a thin rectangle is assumed to produce a plane-strain indentation. By applying rings of blows to a thin disc with the hammer face oriented circum-ferentially or radially, various axi-symmetric distributions of internal stress may be set up. Theoretical stresses were used for calculating changes in stiffness in various harmonic modes of flexure. Hence, effects of distributions of the two types of blow were assessed. The theoretical results, confirmed by controlled experiments, serve to elucidate some aspects of workshop practice.

PRACTICAL WORK IN THE NEW ENGINEERING COURSES … 7

THOSE WHO have been involved in the teaching and organisation of Workshop Practice at the final stage of the Machine Shop Engineering course, will know of many fine examples of precision manufacture carried out in college workshops. It is true that, through this practice, many students have found their only contact with and experience of certain machines and processes. To this extent, Course 63, Workshop Practice, often supplied a particular need, but it could not, in about 100 hours, remedy the training deficiencies from which that need very often sprang.

TEACHING METHOD

No. 3 — Workshop Technology and Workshop Practice To stimulate and guide the students' interest is half the battle in teaching workshop technology: to lecture on it from textbook material is like admitting defeat before the battle has begun. Preparation involves selecting the best combination of necessary information, advice, varied learning activities practical work, visual material and demonstrations. In making the selection, the criteria should be: does this help the student towards insight, correct understanding and good retention, and does it encourage him to make the effort to master essential facts? When it comes to Workshop Practice, the often conflicting aims of developing skill and speed on the one hand, and illustrating, consolidating and co‐ordinating the knowledge gained in Workshop Technology and Craft Science on the other, are generally best seen as appropriate to different staff and different workshops.

The Rev. Arthur Rigg: Pioneer of workshop practice

The Rev. Arthur Rigg: Pioneer of workshop practice

Riemenschneider as a Goldsmith's Model Maker

THE use made by goldsmiths of models carved by sculptors is an interesting problem of workshop practice. It will be discussed here with the specific purpose of showing new evidence that Tilmann Riemenschneider made such models and that goldsmith's statuettes derived from his models are still extant.

Practical Training in Industry for the Graduate in Mechanical Engineering: Part II

Essentially, Part II of this paper recommends planned interweaving of theoretical and workshop practice throughout the period of training. A plea is made for industry's side of training to include some experience in non-engineering, but essential and ancillary branches of the industry, e.g. production and stock control, costing, sales, and general office work. It is emphasized that the larger the organization, the more need there will be specifically to provide this external experience.

British Standards for Workshop Practice. Edited by J. E. Baty. B.S. Handbook No. 2. 1953 Edition. 623 pp. Diagrams and Tables. B.S.I. 21s. net.

British Standards for Workshop Practice. Edited by J. E. Baty. B.S. Handbook No. 2. 1953 Edition. 623 pp. Diagrams and Tables. B.S.I. 21s. net.

Magnetic electron lens aberrations due to mechanical defects

The electron-optical aberrations due to mechanical defects in magnetic lens pole-pieces are calculated, for several lens geometries and a range of excitations, by a slight modification of the computational procedure of Sturrock. The condition that these aberrations shall not predominate over the combination of spherical aberration and diffraction is taken as a criterion of mechanical tolerance. Tolerances for the alinement of the pole-pieces are shown to be well within the limits of normal workshop practice (for a typical lens: the axes of the two pole-pieces must not be laterally separated by more than 30 μ, nor must the angle between them exceed 0.005 radian). Tolerances for ellipticity of the bore and corrugation of the pole-faces are more stringent (typically: the variation in radius or in distance of the pole-face from the mid-plane must not exceed 0.1 μ). The results are generalized in the form of universal curves, designed to facilitate the assignment of tolerances in the case of lenses of any magnitude or accelerating voltage.

Increased productivity by workshop practice

Increased productivity by workshop practice

Increased productivity by workshop practice

Increased productivity by workshop practice

Workshop Practices in Elementary School Physical Education

(1949). Workshop Practices in Elementary School Physical Education. Journal of the American Association for Health, Physical Education, and Recreation: Vol. 20, No. 6, pp. 366-414.