Concept Prototype Keyboard - Design Information

Introduction

The use of CAD enabled each piece to be separated out into an individual DXF file from the master layout to ensure registration for assembly.

The keyboard is made from flat sheets of 1.2mm brushed stainless steel and 6 mm Perspex materials which were waterjet cut. The edges of the Perspex was flame polished.

Cherry MX key-modules are used for the switches, with custom key-tops injection moulded in polycarbonate to a special "white Pyrex" glass effect finish.

Design steps.

The keyboard design is drawn "in the flat" as a full size CAD drawing.

Flat Keyboard - Plan view.

This is not the first drawing! An iterative process of layout and visualisation was undertaken and several different versions explored with, for example, different positions and groupings for the thumbs.

Visualisation

A 3D CAD model was constructed from the flat plan drawing and used to visualise the keyboard with both line and rendered images as the following examples show.

Front view - Line Drawing.

Side perspective view - Line Drawing.

Side perspective view - Rendered image.

The rendered image has smoked rather than clear Perspex as the clear plastic didn't show clearly in the computer generated image.

Assembly

The 3D CAD data also provides the basis for exploded assembly views.

Flat Keyboard - Assembly exploded view, front.

Flat Keyboard - Assembly exploded view, rear.

Cherry MX key-modules (not show in the above assembly diagrams) are fitted to the main stainless steel panel and then discretely wired or fitted with a PCB.

The keyboard is assembled with six M4 dome head socket screws starting from the bottom plate. The swing foot is attached with two M3 screws from the side.

Four clear dome feet (not shown) are attached to the underside, and a cable (not shown) exits the horizontal hole shown at the rear of the spacing piece.

Once assembled the keyboard is ridged due to its laminated structure.

After evaluating and costing the three prototypes several design changes were implemented, including changing the swing foot to fixed feet and increasing the depth of the keyboard to provide better palm support. Additional key positions were added to provide symmetrical left/right key areas and an additional function key [F16] was added to bring the layout in line with current Apple practise.

Flat Keyboard concept and design by Susan Parker MIEE.