SURFACE DEVELOPMENT INTRODUCTION The development of an object is to lay out flat in one plane the shape of all its surfaces such that the development when bent along certain lines will form the shape of the object. The principles of development are used in the industrial sector in the production of most container items. The construction of such objects in the workshop, a geometrical body for instance, takes the following steps.
The design of the parts is first decided in the drawing office, where the orthographic drawing is made showing all the dimension required of the finished object.
Bearing in mind the size of material available and that the developed component can be cut from it.
The development drawing is received in the workshop where the craftsmen the pattern laid out in the drawing.
The sheet is folded along pre-determined bend lines.
Development of Cones The circumference of a cone is found by using the formula
Where R = slanting height r = radius of the given plan, = angle at centre. E.g. If R = 60, r = 30
Centre at O radius OB describe an arc equal to the circumference of the circle and divide it into the same number of equal parts with the circle (Plan).
Centre at O draw arcs to represent t the points of intersection of the cutting plane line.
Mark the point of intersection of the arcs and their corresponding fold lines
