Page 193 - Engineering drawing from first principles using AutoCAD

186 Engineering drawinq [rom first principles

the sides of the spanner. Then draw lines perpendicular to them and which are suffi-
ciently long to insert the 20mm radii.
One line has been drawn on Fig. 8.13. Now turn off ORTHO and SNAPand carefully copy
each line to the right at 30° so that it overlaps the profile of the ellipse. I use the COpy
feature here because the original line then acts as a guide. If you also use the largest
ZOOMframe possible it is quite clear where the profiles of the ellipse and arc overlap. Use
the BREAI( command to clean up the drawing.
The dimensions for the nut are given in Table 8.1. Slide the nut to the left into position.