Composite casing
Casing is important in that it protects the components within from being knocked around, or accidentally shorted. Casing is also very important for giving the user the confidence to really use the device as opposed to admiring it and gingerly trying it out. For our case, we attempted to combine the flexibility and precision of the rapid prototyping printer with the strength, lightness and thinness of carbon-fiber.
Rapid-prototyping plaster
We used the Z-Corp 3D printer to print the skeleton for the casing. Using a 3D modeler we were able to place retention brackets and screw holes to exactly fit the arrangement of the PCBs and LCD display. The main downside to the rapid prototyping material is that it is extremely fragile coming out of the printer, and can be quite brittle when the amount of material is thin.
Working with Carbon fiber
To enhance the strength of the case without increasing the weight, we constructed the top and bottom covers out of carbon fiber sheets. We discovered that our Versalaser laser cutter was unable to cut through the carbon fiber. Thus, our preferred solution is to do the bulk of the cutting using a guillotine-style paper cutter, and to do the finer cutting using a pair of electric scissors. Detail work can be performed using sandpaper.
One thing to watch out for when working with carbon fiber and electronics is that carbon fiber is highly conductive and can short out circuit boards. Therefore, you must be careful to put some type of non-conductive padding between the carbon fiber and the board.