{"id":35,"date":"2023-02-17T13:58:14","date_gmt":"2023-02-17T18:58:14","guid":{"rendered":"https:\/\/pressbooks.bccampus.ca\/level4layout\/?post_type=chapter&p=35"},"modified":"2023-03-31T10:51:08","modified_gmt":"2023-03-31T14:51:08","slug":"round-tapering-elbow-3-piece","status":"publish","type":"chapter","link":"https:\/\/pressbooks.bccampus.ca\/level4layout\/chapter\/round-tapering-elbow-3-piece\/","title":{"raw":"Round Tapering Elbow-3 Piece","rendered":"Round Tapering Elbow-3 Piece"},"content":{"raw":"https:\/\/www.youtube.com\/watch?v=N22lD8cs2Dw&list=PL0YcC46LnT8c9-b3ETwpF1vuLQCMUhSQx&index=3\r\n\r\n \r\n\r\n \r\n
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  1. From the given shop drawing, draw the elevation view<\/strong> of the 2 end gores, based off a given throat radius. Use the standard elbow rule for the miter angle. The 2 end gores for any tapering elbow are always drawn using parallel line.<\/strong><\/li>\r\n<\/ol>\r\n\"\"\r\n\r\n \r\n\r\n \r\n
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    1. Connect the end goes to create the middle gore. Notice that all the size change occurs through the heel section.<\/li>\r\n<\/ol>\r\n\"\"\r\n\r\n \r\n\r\n \r\n
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      1. Draw profiles<\/strong> on both end gores, complete with element lines<\/strong> and labeling<\/li>\r\n<\/ol>\r\n\"\"\r\n\r\n \r\n\r\n \r\n
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        1. Continue the element line<\/strong> through the middle gore<\/li>\r\n<\/ol>\r\n\"\"\r\n\r\n \r\n\r\n \r\n
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          1. Create patterns for both end gores using standard parallel line<\/strong> development. We will use the end gore patterns to help develop the middle gore, so they must be done first<\/li>\r\n<\/ol>\r\n\"\"\r\n\r\n \r\n\r\n \r\n
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            1. We will now deal with the middle gore, it is developed just as a round to round on a pitch<\/strong>, with a few differences<\/li>\r\n<\/ol>\r\n \r\n
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              1. Start with a vertical line 1-2. This is an outside edge and therefore a true length<\/strong> in the elevation view<\/strong><\/li>\r\n<\/ol>\r\n \r\n
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                1. Point 3 will be developed the same as usual, except we don\u2019t have a profile<\/strong> attached to the middle gore. If we did, it would be called a sector<\/strong> not a profile<\/strong>, because it is inside the fitting. So we use the end profiles<\/strong>, which is the first difference in developing this fitting<\/li>\r\n<\/ol>\r\n \r\n
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                  1. Using the profiles<\/strong> from the end gores, use difference in profile<\/strong> to create the following points. We can use the outside profiles<\/strong> because the depth of the fitting has not changed. Because parallel line<\/strong> was used, the depth stays consistent throughout the end gores<\/li>\r\n<\/ol>\r\n \r\n
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                    1. Since there is no profile<\/strong> height at point 2, the full height at point 3 is used.<\/li>\r\n<\/ol>\r\n \r\n
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                      1. Pick up line 2-3 from the middle gore elevation view<\/strong> and transfer to the top baseline, 90\u00b0 to the profile at point 3<\/strong><\/li>\r\n<\/ol>\r\n\"\"\r\n\r\n \r\n\r\n \r\n
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                        1. Pick up the true length<\/strong> of line 2-3 and swing it from point 2. Remember for a round to round, we work from center going both ways. So make sure to swing this line to the left and the right side of point 1<\/strong><\/li>\r\n<\/ol>\r\n\"\"\r\n\r\n \r\n\r\n \r\n
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                          1. Now, the next step is another change from a standard round to round on a pitch<\/strong>. We said that the end gores must be developed first and this is where we use them. If we consider that the depth of the end gores has not changed<\/strong>, but for the middle gore, the length of the stretch out<\/strong> has changed, due to the pitch. If we look at each end gore, regardless of shape, it is longer along the miter line<\/strong> than the calculated stretch out<\/strong>. It has grown in length along the miter line, when compared to the straight stretch out<\/strong>. And the middle gore must attach at this point, at the miter line. So the stretch out for the middle gore must be the same length as the miter line of the end gore<\/strong>. So we need to use the step-off from the miter line<\/strong>, not the profile.<\/strong> The step off<\/strong> from the profile<\/strong> would leave us well short of matching the end gore to the middle gore<\/li>\r\n<\/ol>\r\n \r\n
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                            1. Take the step-off<\/strong> 1-3 from the miter line<\/strong> of the end gore and swing it from point 1. This will create point 3.<\/li>\r\n<\/ol>\r\n\"\"\r\n\r\n \r\n\r\n \r\n
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                              1. Take profile<\/strong> height at point 3 and compare it to profile<\/strong> height at point 4. Remember to work from the outside inwards<\/strong><\/li>\r\n<\/ol>\r\n\"\"\r\n\r\n \r\n\r\n \r\n
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                                1. Transfer line 3-4 from the elevation view,<\/strong> 90\u00b0 to the difference in profile<\/strong> to find the true length<\/strong> and swing it from point 3<\/li>\r\n<\/ol>\r\n \r\n
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                                  1. Take step-off<\/strong> 2-4 from the end gore miter line<\/strong> and swing it from point 2. This will create point 4<\/li>\r\n<\/ol>\r\n \r\n
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                                    1. Take profile<\/strong> height at point 4 and compare it to profile<\/strong> height at point 5. Transfer line 4-5 from the elevation view<\/strong>, 90\u00b0 to the difference in profile<\/strong> to find the true length<\/strong> and swing it from point 4<\/li>\r\n<\/ol>\r\n \r\n
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                                      1. Take step-off<\/strong> 3-5 from the end gore miter line<\/strong> and swing it from point 3. This will create point 5<\/li>\r\n<\/ol>\r\n \r\n
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                                        1. Find the true length<\/strong> of line 5-6 and swing it from point 5<\/li>\r\n<\/ol>\r\n \r\n
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                                          1. Take step-off<\/strong> 4-6 from the end gore miter line<\/strong> and swing it from point 4 to create point 6<\/li>\r\n<\/ol>\r\n \r\n\r\n \r\n
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                                            1. Find the true length<\/strong> of line 6-7 and swing it from point 6<\/li>\r\n \t
                                            2. Take step-off<\/strong> 5-7 from the end gore miter line<\/strong> and swing it from point 5 to create point 7<\/li>\r\n<\/ol>\r\n \r\n
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                                              1. Continue with this process until the fitting is complete at point 14. Remember that line 12-13 will have only 1 profile height and line 13-14 is an outside edge, so it will be true length in the elevation view<\/strong><\/li>\r\n<\/ol>","rendered":"