This section is from the book "Practical Sheet And Plate Metal Work", by Evan A. Atkins. Also available from Amazon: Practical Sheet And Plate Metal Work.

The making up of a pan with moulded sides, as shown in Fig. 71, is not a difficult matter if the pattern for the cut corner is marked out as accurately as possible. This can be done as seen in Fig. 72.

For a square or rectangular-shaped pan (Fig. 71), there is a special method which we will show first.

Fig. 70.

Fig. 71.

and then afterwards explain a general method that will apply to all cases for pans of the regular polygon shape, such as hexagonal, octagonal, etc.

In all cases the first thing to do is to set out the shape of the moulding (Fig. 72), and divide the curved parts up into a number of equal divisions.

The pattern for the corner of a square or rectangular pan can be marked out by first drawing two lines at right angles, and setting along each of these the girth of the moulding by taking the lengths of the numbered parts on the moulding section. Lines square to the girth lines are then drawn from each numbered point, and the length of these cut off equal to that of the line drawn through the same numbered point-on the moulding section up to the measuring line. Thus, to give one example, the line marked 66 on the pattern will be the same length as the line 66 on the moulding shape. When all the required distances arc marked along the pattern lines, the points are carefully joined up, and thus the corner-cut obtained. It should be observed that any part of the moulding section which is straight will also have straight lines corresponding to it on the corner-cut of pattern.

Fig. 72.

The general method will apply to all cases, no matter how many sides the pan has or what is the shape of the moulding. It consists in drawing a base line (Fig. 72), and setting off a joint line at an angle equal to 360° divided by twice the number that the pan has sides. Thus, if the pan has four sides, as in the above case, the joint line will make an angle of -

360 / 4 x 2 45 with the base line. To cut off the pattern lines to their required lengths, they will be made equal to the lengths of the correspondingly-numbered lines running between the base and joint lines.

All the joint lines for pans having from four to ten sides are shown in Fig. 72, and also the shape of cut for the end of one side of an octagonal pan. This being eight-sided, the angle of joint line will be -

360 / 8 x 2 = 45 / 2 = 22½°

The lines are measured between base and joint lines, and their lengths set up from the girth line on pattern, the thick dotted line thus representing the cut for one side of an octagonal pan. In setting out the pattern for a complete pan of this description, the best plan to follow is to first mark out the shape of the bottom, draw lines square to the end of each bottom line, set along the girth, and then proceed to obtain the shape of corner-cuts as explained above.

In shaping the sides of a moulded pan to the required form, it is necessary to be as accurate as possible, if the edges of the moulding are to fit together properly at the corners.

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