Introduction
In a Technology programme a minimum level of skill development, process experience and materials processing are necessary before students can tackle worthwhile tasks with safety and confidence. All tools, machines and systems, carry with their use, varying degrees of danger to the user. It is essential that students be trained in the use of tools in a progressive manner and it is necessary that the student be given introductory exercises in skills development with tools, materials and processes. These exercises should have as their objectives the introduction to measuring and marking out tools, cutting tools and use of hand or power tools. The techniques of shaping, joining and assembling should also be introduced in these exercises Once basic skills are acquired, other skills may be supplied to the student on a need to know basis, arising either from individual student need or from deliberate choice of brief, problem or situation by the teacher. As plastic can be cut, shaped and formed relatively easily in comparison to other materials there is a danger that its use could become over emphasised. This would not allow students to experience a wide range of materials as the syllabus suggests. The safety considerations in using plastics and indeed its environmental effects (disposability) should have an influence on its overall use.
Students must be made aware of the safety precautions required when using glues and proper protective clothing should be worn at all times.
Syllabus Properties
Expansion
An understanding of the properties of materials at the microscopic level is not required. Every material has a unique set of properties. In order to work with materials an understanding of these properties is necessary and may be learned through working with the different materials and evaluation of completed tasks. Students will be expected to have worked with some or all of the following materials: wood, plastic, metal, fabric, composites, ceramics. The following properties should be considered:
- strength
- malleability
- toughness
- brittleness
- elasticity
- plasticity
- conductivity (electrical and heat)
- chemical breakdown. Students should be aware of the general classification of materials, e.g. hardwood, ferrous metals, etc.
Notes and Comments
Appendix G gives a table of the common forms, uses and classification of a variety of materials.
It might be necessary to investigate the suitability of a chosen material for a particular task.
Syllabus Measuring and Marking out
Cutting
! SAFETY
ExpansionMeasuring
Use of rules, callipers, verniers and micrometers etc.
Marking out
Use of squares, gauges, scribers, dividers, and chalks etc. Students should acquire the skills to cut materials accurately and safely. Time must be spent in demonstrating the correct operation, use and care of the commonly used tools and safety must be a priority.
Cutting
Metal Tin snips can be used for cutting light gauge sheet materials. A junior hacksaw is useful for thinner metal and lighter tasks. A guillotine may be necessary if using heavy sheet materials
Cutting Plastics
The cutting technique used for plastics will depend upon the type of plastic being used. Equipment required will range from knives, snips and saws to hot wire cutter for expanded polystyrene.
Cutting Wood
Various types of saws can be used, but for small sectioned wood tenon, dovetail and coping saws are the most appropriate to use.
Notes and Comments
It will be important for students to develop the correct skills that will allow the successful transfer of working drawings to the required materials. The measuring and marking out equipment used will depend upon the material in use.
Students should become familiar with the practical safety measures in the operation and use of hand and power tools and accessories, have a knowledge of the proper work-holding techniques, vices, clamps etc., and have an appreciation of the terms speed and feed. Skroll saw, band saw and hand power tools can also be used when available but priority should lie with the simpler tools.
A skroll saw with a selection of suitable blades would prove particularly useful when working with acrylic materials. A band saw may also be used. Files can be used for shaping hard plastics and the skills developed for metals can also be applied here. Skroll saws and jig saws can be used for curved work on timber and composite boards. Knives can be used to cut adhesive veneers and balsa wood.
Syllabus Expansion Notes and Comments Shaping
! SAFETY
Shaping usually involves the removal of material in small amounts with special tools designed for the purpose
Shaping Metals
Students should
- become familiar with the selection, use and safety of files;
- develop the skills of cross filing, draw filing, concave filing, convex filing and understand their application. Other tools to be made available:
- abrafiles, rasps, sheet abrasives.
- percussion tools: mallets, hammers, centre punches etc.
For the purpose of the course in technology the following material sizes should be available to students:
- light gauge sheet metal in a variety of materials, copper, brass, steel and aluminium etc.;
- strip material of the above prepared from sheet material in suitable sizes
- round material available in a variety of materials ranging from diameter 3mm to diameter 20mm.
Files are used for shaping and smoothing metal. The hacksaw removes metal quickly but leaves a ragged edge. Files can be used to smooth the edge exactly to a line.
The use of the centre lathe if available can produce an extensive range of components and students should familiarise themselves with the use and safety of this machine.
Expansion
Shaping Plastics
Many of the methods used for the shaping of wood and metal can also be used with plastics. The method used will depend on the type of plastic being used. The methods of forming thermoplastics in school workshops are
- line bending
- vacuum forming
- press moulding
- memory technique Students should be aware of these techniques and experience them if possible.
Shaping Wood
Wood planes of various types and sizes are available but a smoothing plane would best suit this course. Chisels also come in various types and sizes, but for general use, the firmer and bevel edge should be used. The use of surforms and the some simple power tools, stand drill, jig saw and reciprocating sander should also be considered.
Notes and Comments
Polyester resin that comes as a thick liquid and whert mixed with a "hardener" or "accelerator" sets into a htard plastic material. This plastic is suitable for gravity casting and can be used to introduce students to the area of mould design and casting.
Some carving chisels may be used in tasks e.g. "Designand make a house name-plate".
Expansion
Fabrics
The shaping of fabrics is usually an integral part of the design. The common tools include scissors, sewing machines, needles and thread.
Ironing and pressing are essential for working with fabrics.
Notes and Comments
A sewing machine that has facilities for straight stitching, zig-zag stitching and an automatic buttonhole will satisfy most of the needs of the technology programme. Knitting machines and looms might be used where available. A small over-locker would save time and is particularly useful for the beginner. Schools should be aware that more sophisticated machines now exist to allow patterns, names etc. to be added. There is a link here with the graphics section of the syllabus. Patterns and templates can be made from grid paper, newspaper or grease proof paper. Iron-on hemming and fabric glue will also be useful.
Syllabus Joining and assembling
ExpansionJoining Metals
Metals can be joined by means of riveting, soldering, folding, fasteners and adhesives. Basic wood joining techniques Students should be aware of the following basic wood joining methods for use in design tasks:
- butt-joint where glue or adhesive or fasteners may be used;
- housed and halving;
- doweling. The various methods of joining materials apart from those already mentioned are nails, screws (wood and machine) bolts, pop-rivets, sewing (machine), soldering and adhesives.
Notes and Comments
Students should have an understanding of the implications of grain direction when designing tasks.
Expansion
Joining plastics Students should be aware that
- plastics particularly acrylic can be joined to wood and metal using nuts and bolts and screws,
- acrylic can be fixed to a softer plastic like PVC with self tapping screws,
- acrylic is usually fixed to acrylic using glue such as epoxy resin or tensol cement.
Joining Fabrics
By means of sewing, adhesives and stapling.
Joining Multimaterials
Use of fasteners, adhesives and staples.
Notes and Comments
Syllabus Finishing of materials
Expansion
The proper finishing of materials should be considered as this will play an important part in the completed task.
Finishing
Metal Plastic dip coating on steels may be used. Copper and brass are usually simply polished and lacquered.
Finishing
Wood Various grades of sandpaper and sanding blocks are required. Finishes that may be used include oil, Polyurethane, paints and stains.
Finishing Plastics
These may be polished. Some are resistant to weather and usually require no protective coating.
Finishing Fabrics
This usually consists of dyeing, water proofing, printing and embroidery.
Notes and Comments A good finish is required, not only for preservation but also for aesthetic purposes.
Enamelling and etching might also be considered as well as painting metals such as aluminium or steel. The type of finish will depend on the task. Preservatives may be needed particularly for outside use.
Appliqu6 might be considered here.