Car Pebble

project by Leila Chouikh and Arran Evans

This project explored the use of rapid prototyping and lost wax bronze casting to produce a product for a specific user.

The Car Pebble was designed for Amy who is a nervous driver. The pebble was designed as an aid to stress relief, as Amy can rub, scratch or squeeze the pebble to relieve tension whilst driving. Amy was actively involved in the design stage as she chose shapes and textures that she was comfortable with.

The first step in the process was to use CAD to create a rapid prototyped model, which would later be cast. The use of CAD allowed us to create detailed and accurate shapes which could not have been done by hand. The model was raised up on wax legs, and covered by plaster to create a plaster cast. When baked in the kiln the model and the wax melted away to leave a hollow. The holes left by the wax created the risers and airs needed to remove air from the cast during bronze casting. It was then bronze cast and finished with metal work. Although we designed the pebble with a variety of different texture the process allowed for an even greater variety as some unexpected textures were created by the 3D printer, such as the thumb print pattern on the front of the pebble.