Page:Sheet Metal Drafting.djvu/198

184 The measuring lines should now be intersected by extension lines dropped from the miter line between the horizontal and rake mouldings, and from each intersection of the profile which appears on the left-hand end of the horizontal moulding (the return miter). Intersections of the stretchout may now be definitely determined by tracing each extension line from its source in the profile to a correspondingly numbered line in the stretchout, Fig. 261. The miter cuts are now drawn. Two blanks from this pattern are needed and they must be formed in pairs.

Using the same set of measuring lines, extension lines are now dropped from each point in the profile, Fig. 259, until they intersect correspondingly numbered lines. Lines connecting these points will give the outline of the pattern for the ends, Fig. 262. A lap is added to the top of the pattern for joining to the "wash" (top surface) of the horizontal moulding. From this pattern two blanks, formed in pairs, must be cut.

The pattern for the panel is obtained by reproducing the surface A, E, F, G, H of Fig. 258. The edge (line BC of profile in Fig. 258) for joining the panel to the rake moulding must be added to four sides of this surface. The spaces between points 19, 20, and 21 of the profile in Fig. 258 must be added to the base of this surface as in Fig. 263. It should be noticed that the space 19–20 of this profile is less than space 19–20 of Fig. 259, because of the sunken panel. From this pattern but one blank is cut, which is formed according to the profile in Fig. 258. The sunken panel leaves small openings along the lines AE and FG of Fig. 258, which may be closed by allowing a "tab" at line A–19 of Fig. 261. However, as this wastes material a small piece of metal may be cut to shape, and inserted after the window cap has been assembled.

The distinction between a rake moulding and a raked or raking moulding should be noted:

A rake moulding is simply a moulding that is inclined to the horizontal. It has the same profile as the horizontal moulding to which it is joined.

A raked or raking moulding is an inclined moulding that joins a horizontal or other moulding that does not lie in the same plane. It does not have the same profile as does the moulding to which it is joined. It takes its name from the fact that its profile must be altered or raked in order to join with the other moulding.