Resistant Materials

Paper Three

What material? – Aluminium – Why?

• Lightweight• Non-ferrous

metal, so corrosion resistant

• Good strength to weight ratio

• Low density

Safety Checks – Coping Saw

Handle tight

Pins in line

Blade facing correct way

(towards handle)

Wood held securely

Blade tight

Blade not damaged

Blade sharp

Types of plane – can you see the difference between the two?

Jack PlanePreparation of material, quick removal of waste material

Smoothing PlaneSmoothing short pieces of wood

Cutting Metal

• Guillotine / Bench shears• Tin snips• Hack saw• Abrafile

Shaping by WastingProcess Wood Metal Plastics

Cutting straight lines Tenon saw (dovetail saw for fine work)

Hacksaw (junior hacksaw for small work)

Hacksaw (junior hacksaw for small work)

Cutting curved lines Coping saw (fret saw for fine work) Abra saw (piercing saw for fine work). Tin snips can be used on thin sheet metal

Abra saw (piercing saw for fine work). A coping saw can also be used

Trimming cut edges to a straight line

Jack plane or smoothing plane Flat or hand file Flat or hand file

Trimming cut edges to a curved line

Spokeshave or rasp Round or half round file Round or half round file

Cutting grooves and slots Tenon saw to cut sides, then wood chisel or coping saw

Drill holes at ends, then use abra saw

Drill holes at ends, then use abra saw or piercing saw

Guillotine / Bench shear Cutting thin metal / small sections of metal

Draft angles for moulds

Moulds for vacuum forming need a draft angle of 5-7 degrees otherwise they cannot be removed

Fluting adds strength

AnthropometricsAnthropometry is the branch of human sciences concerned with body measurements such as body size, shape and strength. This is used by ergonomists to ensure that products, such as seats, fit and suit as many users as possible.If you are designing a seat, you need to take the following measurements into account.

Anthropometric estimates for British adultsaged 19-65 years (in mm, from Pheasant)

Dimension 5th %ile 50th %ile 95th %ile

A Sitting height850 910 965795 850 910

B Sitting shoulder height540 595 645505 555 610

C Shoulder breadth420 465 510355 385 435

D Hip breadth310 360 405310 370 435

E Buttock-popliteal length440 495 550435 480 530

F Popliteal height395 440 490355 400 445

MALE FEMALE

 

Marking out MetalsProcess Metal

Lines Scriber

Lines at right angles to an edge

Engineer's try square

Lines parallel to an edge Odd-leg calipers

Marking for a mortise N/A

Marking a circle Dividers

Marking the centre of a hole Centre punch

Marking an irregular shape Template

Marking out WoodProcess Wood

Lines Pencil

Lines at right angles to an edge Carpenter's try square

Lines parallel to an edge Marking gauge

Marking for a mortise Mortise gauge

Marking a circle Pair of compasses

Marking the centre of a hole Pencil

Marking an irregular shape Template

Marking out PlasticsProcess Plastics

Lines Felt-tip pen

Lines at right angles to an edge Engineer's try square

Lines parallel to an edge Odd-leg calipers

Marking for a mortise N/A

Marking a circle Dividers

Marking the centre of a hole Felt-tip pen

Marking an irregular shape Template

a waxy pencil used to write on china, glass, or other hard surfaces

Chinagraph Pencil

Folding bars

Joining Metals - Soft soldering

Quick method of joining copper, brass and tinplate when little strength is required in the joint. Also for fixing electronic components

Weather resistanceDurableMore easily moved aroundComfortable armrestsWill not rustEasier to cleanStronger (must be qualified) Polypropylene has good resistance to work fatigue

Suitable joint for corner A

Mortise & Tenon

Halving

Bridle

Dowell

Clamping (cramps)

Sash Clamps These clamps are for big tasks such as sash windows, table

tops, doors etc. Usually several such clamps are required

Clamping

• G Clamp

Checks when Clamping

• Are pieces in correct position (square, flat)• Joints pulled together• Excess glue removed• Use scrap glue to spread pressure and avoid

damage• Clamps not over tightened• Clamps tight / secure

Drilling at an angle

• Table of bench drill rotated to provide angle.

• Work piece clamped in place

Table

Drilling at an angle

• With table of bench drill horizontal, a wedge to provide the angle is placed under the work piece

• Work piece securely clamped

Table

Bending Rods of Metal

• Watch the short video clip to understand how to bend metal rods. Note: the retention method; the jig; the method of force

Advantages of a cutting gauge instead of pencil and try-square

• Quicker• More accurate• Cuts fibres of wood• Cannot be rubbed off

Process Tools / equipment used

Mark out Pencil, rule, sliding bevel, marking knife, mitre square

Saw off waste Tenon saw, coping saw, machine saws

Make sawn edges smooth

Sanding disc, file, chisel, plane, sand paper

Type of nailsROUND WIRE NAIL - This is used for general work. It is not attractive in shape and it can split wood when hammered in position

OVAL WIRE NAIL - This is a long nail and care must be taken when it is hammered into the wood. It is unlikely to split the wood.

LOST HEAD NAIL - This is ideal if it is necessary to hide the head of the nail as a punch can be used to hammer the head beneath the surface level.

PANEL PIN - A very popular way of joining woods although glue is usually included as part of the join.

TACK - Can be used for fixing textile materials to wood for example, fixing upholstery to furniture.

ANNULAR NAIL - The teeth of this nail hold it in place firmly. Therefore, it is used for fixing plywood and other materials.

HARDBOARD PIN - The diamond shaped head is hidden when used in materials like hardboard

• After reading the PPP and taking notes you should retake Paper 3. You should answer all questions except 11f, 12c(ii), 12f, 12g and 13e.

• Attempt all questions without referring to the notes you made. If you get stuck, leave it until you've answered all the questions you can. Then look at your notes to help you answer those questions you were stuck on.

• You might have to do some further research to answer some of question 13