A-1. The images below show details of a curved metal shade from a set of traffic lights - Leaving Cert DCG - Question A-1 - 2016

To complete the surface development, follow these steps:

1. Projection of point from elevation to development view: Start by projecting the given point from the elevation (coordinates of point P) onto the surface development.

   • The projection will be a vertical line from point P down to the development view.

2. Location of points m1 and m2 on development view: Identify points m1 and m2 from the elevation and project these onto the development view.

   • Points m1 and m2 may be located by measuring their distances from the edge of the cylinder.

3. Projection of "turning point" from elevation to development view: For this part, locate the turning points on the cylinder (noted as m1 and m2) and project them horizontally onto the development view.

4. Location of "turning points" on development view: Place the turning points on the development view using the projected lines from the cylinder's elevation.

   • Ensure they align correctly with the curvature of the shade.

5. Projection of given points on underside of cylindrical surface to elevation: Project the determined points from the underside of the cylindrical surface back to the elevations.

   • This ensures alignment of both views.

6. Projection of these points to development view: After defining their positions in the elevation, project these points down to the development view.

7. Vertical sub-division to establish intermediate points on development view: Introduce vertical lines to create sub-divisions between points to improve accuracy in the development.

8. Location of remaining points on development view: Fill in any remaining points needed to complete the development, ensuring a smooth curvature.

9. Completion of surface development: Finally, refine the development shape for accuracy, ensuring all curves and angles are correct to represent the finished shade.