## Jrheberrechtlich gescht

A plan and elevation of the base of a candlestick are shown in Fig. 8. Draw a another elevetion when the base is viewed in the direction of the arrow and b an accurate isometric view of that half of the candlestick base indicated by the letters abed on the plan view. The edge ab is to be in the foreground of your drawing Southern Universities' Joint Boerd See Ch. 8 for information not in Ch. 3 . 10. Fig 10 shows two views of a cylindrical rod with a circular hole. Make an isometric drawing...

## Sch

This operation is shown in Fig. 3 10. Tha ratio between the I rue length and the isometric length is isometric unoth true length x 0 8165. This ratio is constant for all lines measured parallel to any of the isometric axes. If you are asked to draw an object using an isometric scale, your scale may be constructed as in Fig. 3 10 or you may construct a conventional plain scale as shown in Fig. 3 11. The initial length of this scale is 100 x 0.8165 - 81.65 mm. The scale is then completed as shown...

## Welding Engineer Caricature

Fig 18 7 Changes in direction of a section line SECTION Z-Z ONE MOL Ol NC SHOW , roe CLAWTYI SCREW THREADS The screw thread is probably the most important single component in engineering. The application of the screw thread to nuts, bolts, studs, screws, etc. provides us with the ability to join two or more pieces of material together securely, easily and. most important of all, not permanently. There are other methods of joining materials together but the most widely used ones riveting,...

## Freehand sketching

The bility to sketch neatly and accurately is one of the most useful attributes that a draughtsman can have. Freehand drawing is done on many occasions to explain a piece of design quickly to a colleague to develop e design see Fig. 16 10 and even to draw a map showing someone how to get from one piece to another. Technical sketching is a disciplined form of art. Objects must be drawn exactly as they are seen, not as one would like to see them. Neat accurate sketches are only achieved after...

## Rechtlich gesch

To construct a square givsn the diagonal Fig. 2 22 3. With centra 0 and radius OA OC draw a circle to cut the bisecting line in B and D. To construct a rectangle given the length of the diagonal and one of the sides Pig. 2 23 3. With centre O and radius OB - OD draw a circle. 4. With centre B and radius equal to the length of the known side, draw an arc to cut the circle m C. 5. Repeat step 4 with centre D to cut at A. ABCD is the required rectangle. To construct a parallelogram given two sides...

## Ichtztes Ma

Fig. 3 hows the outline of the body of a depth gauge. Make ah oblique drawing, twice full size. of the body 3. Fig. 3 hows the outline of the body of a depth gauge. Make ah oblique drawing, twice full size. of the body 4. Draw, full size, en Oblique Protection of the car brake light switch shown in Fig. 4. It should be positioned so that it is resting on surface A. with the cylinder B towards you. South-East Regional Examinations Board 5. Fig. 5 shows two views of a holding-down clamp. Draw...

## Urheberrechtlich geschtztes Material

The theorem of Pythagoras says that 'In a right-angled triangle, the square on the hypotenuse is equal to the sum of the squares on the other two sides'. When this theorem is shown pictorially. it Is usuatly illustrated by a triangle with squares drawn on the sides. This tends to be a little misleading since the theorem is valid for any similar plane figures see Fig. 7 14 . This construction is particularly useful when you wish to find ihe sue of a circle which has the equivalent area of two or...

## Engineering drawing

The first step a manufacturer must take when he wishes to make en article is to produce e drawing. First e designer will make a preliminary sketch and then a draughtsman will make a detailed drewing of the design. Since neither the designer nor the draughtsman will actually make the article, the drawings must be capable of being interpreted by the men in their workshops. These workshops may be sited a long way from the drawing office, even overseas, and so the drawings produced must be...

## Drawing Conventions

Fig. 18 17 Boh heeds end Kiev, heads There are many types of heads for bolts and screws apart from the standard hexagonal head Some are shown in Fig 18 17. Fig. 18 17 shows only e few types of bolt end screw heeds that are in use. There are Wedged-Shaped Heads, Tommy Heads. Conical Heads. Hook Bolts and Eye Bolts. There ere Small. Medium and Large Headed Square screws. 60. 120 and 140 countersunk screw heads with straight slots, cross slots and hexagonal slots. There are Instrument Screws and...

## Diagonal Scale Drawing

Three examples of diagonal scales follow. This scale would be used where the drawing is twice the m of the natural object and the draughtsman has to be able to measure on a scale accurate to 01 mm The longest natural dimension is 60 mm. This length is first divided into six 10 mm intervals. The first 10 mm is then divided into 10 pans, each 1 mm wide scaled Each of these 1 mm intervals is divided with a diagonal into 10 more equal parts To construct a diagonal seal , 30 mm 1 mm, 4 m long to...

## The construction of circles to satisfy given conditions

About 6000 years ago, an unknown Mesopotamian made one of the greatest inventions of alt time, the wheel. This was the most important practical application ever made of a shape that fascinated early mathematicians. The shape is, of course, the circle. After tho wheel had been invented, the Mesopotamians found many more applications for the circle than just for transport. The potter's wheel was developed and vessels were made much more accurately and quickly. Pulleys were invented and engineers...

## Urheberrechtlich geschDUIes Material

Fig. 2 hows the front elevation and plan of an ink bottle stand. Make e full size isometric drawing of the stand with corner A nearest to you. Hidden details should not be shown. West Midlends Examinations Board 3. Fig. 3 shows the development of a hexagonal box. Draw, in isometric projection, the assembled box standing on its base. Ignore the thickness of the material and omit hidden detail. North Western Secondary School Examinations Board See Ch. 14 for information not in Ch. 3 . 4. Three...

## Some more problems solved by drawing

This chapter introduces the student to some more drawing techniques It should be emphasized that the topics are only introduced all of them can be studied in much greater depth and any solutions offered in this chepter will apply to simple probleme only. AREAS OF IRREGULAR SHAPES It is possible to find, by drawing, the area of an irregular shape. The technique does not give an exact answer but. carefully used can provide a reasonable answer. Look at Fig. 17 1. The shape is trapezoidal with...

## Enlarging and reducing plane figures and equivalent areas

Beginning at R. draw the sides of the larger figure parallel to the sides of the original smaller figure. This construction works equally well for reducing the size of a plane figure. Fig. 7 2 shows an irregular hexagon reduced to 4 9 its original size. These constructions are practical only if the figure which has to be enlarged or reduced has straight sides. If the outline is irregular, a different approach is needed. Fig. 7 3 shows the face of a down in two sizes, one twice that of the...

## The blending of lines and curves

It is usually only the very simple type of engineering detail that has an outline composed entirely of straight lines The inclusion of curves within the outline of a component may be for several reasons to eliminate sharp edges, thereby making it safer to handle to eliminate a stress centre, thereby making it stronger to avoid extra machining, thereby making it cheaper and last, but by no means least, to improve its appoarance This last reason applies particularly to those industnes which...

## Further problems in loci

After 1 6 rev. the position of P the intersection of the line Pt Pi and the radius. marked off from 0 . This is repeated for the twelve divisions Fig. 16 1 also shows the beginning of a second cycloid and it can be seen that the change from one cycloid to another is sudden. If any locus is plotted and has an instantaneous change of shape H indicates that there is e cessation of movement Anything that has mass cannot chsnge direction suddenly without first ceasing to move. The point of the...

## Oblique projection

Oblique projection is enother method of pictorial drawing. It is simpler than isometric but it does not present so realistic a picture. Fig. 6 1 shows a shaped block drawn in oblique projection There are three drawings of the same block in Fig. 6 1. They all show the front face of the block drawn in the plane of the paper and the side and top faces receding at 30 . 49 and 6C on the three drawings An oblique line is one which is neither vertical nor horizontal, and the receding lines in oblique...

## Tangency

A tangent to a circle it a ttraight lino which touches the circle at one point. Every curve ever drawn could have tangent drawn to it but this chapter is concerned only with tangents to circles. These have wide applications in Engineering Drawing since the outlines of most engineering details are made up of straight lines and arcs. Wherever a straight line meets an arc, a tangent meets a circle. To draw a tangent to e circle from any point on the circumference Fig. 5 1 1. Draw the radius of the...

## Eight-course 125mm Stepped-off Diagonal Method

To construct a regular octagon given the diagonal, i. o. within given circle Fig. 2 29 1. Draw the circle and insert a diameter AE. 2. Construct another diagonal CO, perpendicular to the first diagonal. 3. Bisect the four quadrants thus produced to cut the circle in B. D. F, andH. To construct a regular octagon given the diameter, i.e. within a given square Fig. 2 30 1. Construct a square PORS. length of side equal to the diameter. 2. Draw the diagonals SQ and PR to intersect m T. 3. With...

## Jrheberrechtlich geschtztes Material

It is aometimes necessary to draw circles or curves on faces which are not parallel to any of the three isometric axes Fig. 3 7 shows a cylinder cut at 45 . Two views of the cylinder have to be drawn a plan view and an elevation. The plan view is divided into stripe and the positions of theee stripe are projected onto the elevation. The base of the cylinder is drawn in isometric in the usual way. Points 1 to 20. where the strips cross the cncI ere projected vertically upwards and the height of...

## Parti Geometrie drawing

Urheberrechtlich gesch tztes Material Before you start any drawing you first decide how large the drawings hove to be. The different views of the object to be drawn must not be bunched together or be too far apart If you are able to do thrs and still draw the object in its netural size then obviously this is best This is not always possible the object may be much too large for the paper or much too small to be drawn cleerty. In either case it will be necessary to draw the object to scale' The...

## Construction Of Triangles Perimeter Altitude Vertical Angle Given

Preface to the second odition iii 1 Scale 3 The representative fraction plain scales diagonal scales proportional scales 2 The construction of geometric figures Construction of the following tnanglea Equilateral. given one of the sides Isosceles, given the perimeter and altitude Scalene, given base angles and altitude Scalene, given base, altitude end vertical angle Scalene, given penmeter and ratio of sides Scalene, given perimeter, altitude and vertical angle Similar triangles with different...

## Developments

There re two besic ways of fashioning a piece of material into a given shape. Either you start with a solid lump and take pieces off until the required shape is obtained or you have tha material in sheet form and bend it to the required shape It should be obvious that if the latter method is used, the sheet material must first be shaped so that after it is bent you have the correct sue and shape. If. then a component is to be made of sheet material, the des gner must not only visualize and draw...

## Conic sectionsthe ellipse the parabola the hyperbola

Fig. 11 1 shows the five sections that can be obtained from a cone The tnangle and the circle have been discussed in earlier chapters this chapter looks at the remain -ing three sections, the ellipse, the parabola and the hyperbola These are three very important curves. The ellipse can vary m shape from almost a circle to almost a straight line and is often used in designs because of its pleasing shape The parabola can be seen m the shape of electnc fire reflectors, rader dishes and the main...

## How To Draw Loci For Crank Mechanism

A locus plural foci is tha path traced out by a point which moves under given definite conditions You may not have been aware ot it but you have met loo meny times before. One of the most common loci is that of a point which moves so that its distance from another fixed point remains constant, this produces a circle Another locus that you know is that ot a point which moves so that its distance from a line remains constant this produces parallel lines. Problems on loci can take several...

## Orthographic projection

Orthographic projection is the solution to the biggest problem that a draughtsman has to solve how to d aw. with sufficient clarity, a three-dimensional object on a two-dimensional piece of paper The drawing must show quite clearly the detailed outlines of all the faces and these outlines must be fully dimensioned If the object is very simple, this may be achieved with a freehand sketch. A less simple object could be drawn in either isometric or oblique projections, although both these systems...