Bevels On Oblique Planes

be brought into one plane ; it does not really matter which plane it is. As it may not be clear how the elevation of the brace is obtained, this will be first described.

Draw the line a-b, Fig. 2, at the pitch the brace is desired, and the b'ne 1--2 perpendicular to this; upon this set off the half-diagonal of the given brace on either side, obtaining the dimension from a drawing or the stuff itself. Draw-parallels to a b through 1-2, which will give the projections of the upper arid lower edges.

The section of the brace is dotted in to make the explanation clearer ; this is drawn by setting off the transverse diagonal and joining up the corners 1-2-3-4. Next draw a line square to the pitch through the lower corner and turn the sides down upon it. 1 )raw parallels to the edges through these points and intersect them by perpendiculars drawn from each end of the brace as at c-d. Join the points so obtained to points a and b, and the bevels will be found.

A similar post is shown in Figs. 5 and 6. Here the post is so placed that the braces pitch against its diagonal.

The same method is used to obtain the bevels for the right-hand brace, which should offer no difficulty to the student, although the bevels obtained differ from the last set. The braces being square in section, both cuts are really alike, and the development of the undersides is unnecessary, but both are shown to make the method clear.

If the brace were at an angle of 45" only one bevel would be necessary, as each end would be alike. On the left side of Fig. 5 the brace is shown with its sides parallel to the vertical plane, consequently the down cut and foot cut are shown correctly in the elevation. Two methods of obtaining the edge cut or bird's-mouth are shown. First the point e may be thrown down level with x, the lowest point in the bird's-mouth, and projected into the plan, where it is intersected at e" by the side h" produced. Join e"--x' and the true shape of the bird's-mouth is seen. Second, a development of upper side of brace may be made 011 the elevation, projecting across it the point x to the middle, where it meets the angle of the

Was this article helpful?

0 0
Pencil Drawing Beginners Guide

Pencil Drawing Beginners Guide

Easy Step-By-Step Lessons How Would You Like To Teach Yourself Some Of The Powerful Basic Techniques Of Pencil Drawing With Our Step-by-Step Tutorial. Learn the ABC of Pencil Drawing From the Experts.

Get My Free Ebook

Post a comment