Designing for a 3D World
We live in a world where every object we see and touch and move is located in three-dimensional (3D) space. This could be something simple like a toothbrush or complex like a motor car. Fifty years ago industrial designers and engineers would have imagined these objects and then hand drawn them on paper. Using a milling machine, a skilled craftsman would have transformed these flat two-dimensional (2D) drawings into recognisable 3D artefacts. How things have changed!
In a previous blog we introduced the Pandia, our digital X-ray camera. A key component of the camera is the housing which we have called the cradle. Our product engineer Andrew Tucker was faced with a number of design challenges. First, the cradle had to accommodate the electronic sensor, a charge-coupled device (CCD) that has dimensions of 243 x 27 x 12 mm. Second, it had to provide mounting points for the printed circuit boards (PCBs), and third, it had to facilitate the electrical connectivity between the CCD and the PCBs. Finally, the cradle needed to hold an embedded lead plate to provide shielding of the electronics from X-ray damage.
Andrew had at his disposal a 3D modelling tool called SolidWorks, a sophisticated computer aided design (CAD) package (not to be confused with the other CAD, computer-assisted diagnosis, also covered in a previous blog). Andrew then designed the cradle, with all its features, in 3D.
To create a prototype of the cradle, Andrew turned to the latest technology that is transforming the manufacturing industry: 3D printing. In contrast to a milling machine, which is based on a subtractive process, 3D printing employs an additive process, where an object is created by laying down successive layers of material. Andrew called on the services of Skeg, who not only manufactured our prototype but also used the 3D printed cradle to create a silicon mould, thus enabling multiple devices to be fabricated.
“I chose a polyurethane material for the cradle since it can be easily moulded and had to be made from a non-conductive material,” said Andrew. “The cradle is a great example of a simple looking part which is in fact feature rich and designed under an array of high tolerance constraints.” Our electronics engineer Benjamin Lunsky leaves this weekend for the UK where our first Pandias off the production line will undergo extensive testing prior to achieving the CE Mark.