The original 50’s rally computer had a bubble screen to reduce glare thus ensuring that the navigator or driver could read the mechanical pilot hands.
In creating GaugePilot, every detail had to be correct. Trials were completed using flat screens, but they made the GaugePilot look too modern - more like a modern sat nav than a period 50’s accessory.
The screen had to be a bubble to give that right look, but also had to have suitable optical performance for the LED backlit graphical display driving it from behind.
There are a number of methods available for producing a bubble screen. The first is blow forming. This is the traditional method that was used to form aero cockpit canopies by using heated air to stretch a heated plastic sheet to form a bubble shape. The problem with this method is that although the clarity is well maintained the shape is not consistent, and the forming of complex shapes to allow, for example, seals around the buttons is simply not possible.
We experimented with the second method, vacuum forming. This produced a more regular and uniform shape but the materials available created optical distortion.
Our third and final option was to injection mould the screen. This would produce a repeatable product and the wide choice of available plastic material combinations made our challenging performance requirements achievable. Injection moulding it was to be.