Textbook of Engineering Drawing, Second Edition

_____ Development of Surfaces 7.13

0' a"= oA = L = True length of the generator

Fig. 7.13

Note: To transfer a point say 4 on od to the development.

(i) Determine the true length of 0-4 by drawing a horizontal through 4 meeting od at 4.

(iI) On the generator 00, mark the distance 0-4 equal to 0-4.

Problem : Figure 7.14a shows a tools tray with an allowance for simple hem and lap-seam.

Figure 7.14b represents its development with dimensions.

ISO

..

,...-.... ~IS!

I

I~!

"--' ..

150 50 5

260

(b)

Fig. 7.14