Deans Community High School Cone Development Graphic Communication CDT Department

Development of surface (1) Mark the position where the apex of the Development will be placed. 1 2 9 8 7 6 5 4 3 3 Draw the first generator. 2 1 Draw the base line of the Development. 12 Step off the size to each generator point along the base. 11 10 Number each of the points found. 9 Draw generator lines from the apex to each of the points on the base. 8 7 6 5 3 4

Development of surface (2) It is necessary to find the ‘true length’ of the cut points along each generator. To find these sizes project a line through each point on the cut of the Elevation to the outside generator. 1 2 9 8 7 6 5 4 3 3 2 1 12 11 9 1 8 7 2 6 10 Mark each of the found points with a small dot. 9 8 7 6 5 1 2 7 3 8 9 1 1 1 4 6 1 2 3 5 4 5 4 3 2 1

Development of surface (3) Measure the distance from the apex to each point on the outside generator. 1 2 1 1 1 1 3 2 Transfer this size to the correct generator on the Development. 2 9 3 1 8 4 12 Mark each point with a small dot. 7 5 6 11 Draw a smooth curve through each point found. 10 9 8 Darken each of the other outlines on the Development. 7 6 5 9 1 1 1 1 2 1 2 7 4 3 8 9 1 1 1 6 1 2 3 8 7 6 5 4 5 4 3 2 1

True Shape of cut (1) Project each of the points on the cut of the Elevation away at right angles to the cut surface. 9 10 8 11 1 2 7 1 1 12 1 6 1 1 5 3 2 2 4 3 2 9 Draw a datum line on the True Shape – in this case the centre line has been chosen. 3 1 8 4 12 7 5 6 11 10 Number each of the lines projected up to the True Shape. 9 8 7 6 5 1 1 1 1 2 1 2 7 4 9 3 6 8 9 1 1 1 3 8 7 6 5 4 5 1 2 4 3 2 1

True Shape of cut (2) Measure the sizes from the cut points to the centre line on the Plan and transfer each of these sizes to the correct lines on the True Shape. Note – These sizes can also be measured from the End Elevation. Mark each of the points with a small dot. 9 10 11 1 2 8 7 1 1 12 1 6 1 1 5 3 2 2 4 9 3 2 3 1 8 4 12 7 5 6 11 10 9 8 7 6 5 1 1 1 1 2 1 2 7 9 3 8 9 1 1 1 4 6 3 8 7 6 5 4 5 1 2 4 3 2 1

True Shape of cut (3) To finish the True Shape draw a smooth curve through each of the points found. 9 10 11 1 2 8 7 1 1 12 1 6 1 1 5 3 2 2 4 9 3 2 The final drawing should look like this. 3 1 8 4 12 7 5 6 11 10 9 8 7 6 5 1 1 1 1 2 1 2 7 9 3 8 9 1 1 1 4 6 3 8 7 6 5 4 5 1 2 4 3 2 1

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