Desktop Speakers


Iron ore has been mined for thousands of years. It’s inherit heirloom qualities are evident from the many precise tools, building facade, and manhole covers that still exist and are produced today. The process of sand casting iron shares many of the same considerations of injection-molding manufacturing process such as draft, wall thickness, mold flow and shrinkage. 2010.

This project was an exploration of both manufacturing and acoustics.


Pattern Board Fabrication

Model Explorations

The shape of the enclosure was arrived at through a combination of sketching and CAD. Once the final form was resolved, each component of the pattern board was turned on the lathe and assembled onto a board.


All the turned pieces are carefully assembled and glued to a common board that is used to press into sand. Front and center are the sprue, gates, and runners which allow the iron to poured centrally to feed multiple forms.

Pattern Board

This shows how the core and main pattern board interact. The yellow dents where the core (see below) will sit once the pattern has been placed in the sand.

Cast Iron Speakers pattern board.png

Core Box Fabrication

Design Considerations

The most challenging aspect of shaping the enclosure was achieving zero draft on the front face to minimize post-machine work and preserve the primary datum. To get around this I designed a two-part core box that includes a side pull, enabling the zero draft.

Packing Sequence

1. Core box is packed with sand
2. Outside box is unlatched and pulled away from the primary body.
3. Primary body is lifted up horizontally to prevent disturbing the packed sand form.

Cast Iron Speakers Core box _ 1po.png