In isometric drawing, it is often the case that the angle in the perspective plane needs to be calculated.

For example, when the angular separation for a ring of circles needs to be found.

This example involves drawing the bores in a flange. As can be seen in the technical drawing, the bores are evenly distributed across the surface of the flange. As the flange is flattened at one point, the orientation for the first bore must be established and then the angles between the bores.

The Perspective rotation tool enables the bores to be easily drawn into the flange drawing.

If you wish to draw the flange without the bores yourself, the key dimensions can be found in the figure at the top of the following page. You can set the thickness of the flange as you wish. You should already be familiar with the tools and functions required to draw the flange.

Alternatively, you can use the flange drawing that is provided. As usual, the file is located in the Arbortext-IsoDraw-install-path\Tutorial\Tutorial IsoDraw folder.

flange.idr (flange without bores)

Grid Alignment, Element Snap, and Dimensions must be on.

Grid Snap must be off.