Locomotive boiler construction; a practical treatise for boilermakers, boiler users and inspectors .. . Figure 7Wheel for measuring. 5i-5i° is arrived at. At this position the front line andthe back line of the sheet coincide in the left hand view,which means that the sheet is a rectangle below this 5 and 5^ draw two lines at right angles to theline joining these points, and with a radius equal to thelength along the curved line from 5 to 6, strike two arcsfrom 5i and 5^ as centers. The points 6X-6X° will thusbe determined. One half of the sheet is now developed,and since the figu
Locomotive boiler construction; a practical treatise for boilermakers, boiler users and inspectors .. . Figure 7Wheel for measuring. 5i-5i° is arrived at. At this position the front line andthe back line of the sheet coincide in the left hand view,which means that the sheet is a rectangle below this 5 and 5^ draw two lines at right angles to theline joining these points, and with a radius equal to thelength along the curved line from 5 to 6, strike two arcsfrom 5i and 5^ as centers. The points 6X-6X° will thusbe determined. One half of the sheet is now developed,and since the figure is symmetrical the other half will besimilar, A-C being the center line of the sheet. As a 26 Development of irregular shaped sheet. check upon the construction, the length of the developedline from ox to 6X should be exactly the same as the lengthof the neutral line of the sheet from o, around to 6, andthe length of the developed line 0^-6^°, should be equalto the length of the neutral line of the sheet from o°. Figure-8Paper measuring method. around to 6°. In order to get these lines equal, a measur-ing wheel as shown in Fig. J is convenient. If the sheet islaid down less than full size, which itfrequently is, in a drawing room, this measuring wheeLshould be graduated to the same scale as the outer edge of this wheel is beveled so as to form asharp edge. The zero or o of the wheel is set to the o ofthe line of the sheet and *the instrument run along theneutral line, the number of inches being noted. The in-strument is then run along the development and thelength of the lines must correspond. Indeed it is a goodthing to check frequently as one goes along, as any erroris then readily caught. In the absence of one of these .wheels, a paper scale 27 Laying out dome sheet. ±Hoia cp. 8A Laying out dome sheet. as Fig. 8, graduated to the same scale as the drawing,can be used. It is bent to coincide with the neutral lineof the sheet and the length of the sheet tr
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Keywords: ., bookcentury1900, bookdecade1910, bookidlocomotivebo, bookyear1912
