Sheet Metal Technology by David Gingery
Author:David Gingery [Gingery, David]
Language: eng
Format: azw3
Publisher: David J. Gingery Publishing, LLC
Published: 2016-01-20T16:00:00+00:00
You have seen that a cylinder may look like a square or rectangle in a side plan view and a cone may look like a triangle. Yet another geometric shape that looks like a triangle in a side plan view is a pyramid. And a top plan view of a pyramid looks like a square with lines drawn from corner to corner as in figure 16. The routine for the solution of this pattern problem is called “Triangulation” because we use a right triangle to solve the true length of some of the lines. The solution of the pyramid pattern is similar to that of the cone in some respects, but Triangulation is significantly different than radial line development in its many applications.
The triangulation routine is based upon the law of right triangles. A right triangle is one with an angle of 90 degrees between two legs. If you draw two right triangles each with base and perpendicular leg of the same length the hypotenuse of both triangles will be the same length. And so we use what can be termed a “solution triangle” to solve the unknown lengths seen in the plan views. It is a very simple process that will enable you to develop patterns for seemingly complex figures with great ease.
As in other routines, we begin by drawing a full size top and side plan view. Again the perspective view gives you a clear concept of what the figure is to be, but it is not useful in the solutions process.
The corners in the top plan view are marked A, B, C, and D. Since you are viewing the figure as though looking straight down at the peak, point C, you are seeing the true dimensions of each of the four base sides and so they do not have to be solved. But the vertical lines are not true because you are viewing them at an angle.
Point X represents the center of the base which is directly below point C and so it is not visible. But if a vertical line were drawn from point X to point C it would represent the vertical leg of a right triangle. The true length of the vertical leg can’t be found in the top plan view. But the true length of the base of the triangle is found between A and X, B and X, D and X and E and X. Although point X is not visible in the top plan view, the true length of the base is clearly seen between each corner and point C since point C is directly above X.
Notice that the side plan view presents the two base corners designated A and B as though the upper figure were rotated 90 degrees to give a direct side view. Again we see the base dimension in its true length between A and B. But the diagonal lines between A and C and B and C are not true length because they are seen at an angle.
Download
This site does not store any files on its server. We only index and link to content provided by other sites. Please contact the content providers to delete copyright contents if any and email us, we'll remove relevant links or contents immediately.
Audition by Ryu Murakami(4076)
The Body: A Guide for Occupants by Bill Bryson(3762)
Adulting by Kelly Williams Brown(3644)
Housekeeping by Marilynne Robinson(3382)
Zero Waste Home by Bea Johnson(3277)
Be in a Treehouse by Pete Nelson(3196)
Seriously... I'm Kidding by Ellen DeGeneres(3087)
Better Homes and Gardens New Cookbook by Better Homes & Gardens(2936)
Barkskins by Annie Proulx(2867)
The Healing Self by Deepak Chopra(2781)
Hedgerow by John Wright(2765)
The Life-Changing Magic Of Tidying Up- The Japanese Art Of Decluttering And Organizing (v5.0) by Marie Kondo(2733)
Spark Joy by Marie Kondo(2665)
The Genius of Japanese Carpentry by Azby Brown(2590)
The Cellar by Natasha Preston(2577)
Work Clean by Dan Charnas(2549)
120 Days of Sodom by Marquis de Sade(2411)
A Monk's Guide to a Clean House and Mind by Shoukei Matsumoto(2394)
The Book of Numbers by Peter Bentley(2392)