This is the first segment of a series of articles written by Aquatica's technical advisor, Jean Bruneau, about the process of making an underwater housing. For an introduction to the series and a listing of all the installments, head to this page.
By Jean Bruneau
Part 1: Designing
Every once in a while people ask me how housings are made, so to dispel any myths I have decided to take you on a tour of our company and show you the process from the ground up. No folks, it’s nothing like the machinery seen in Charlie Chaplin movies. Underwater housings do not come out of an oven and we certainly don’t have a large steam whistle calling the breaks like in the cartoons. In order for you to have fun creating images underwater, we need to be serious about our work (that does not mean we are unpleasant people, we love our fun as much as any of you)!
The first step in creating a housing is not really taken by us, but by the camera manufacturer. The camera that they decide to create obviously has a major influence on whether or not it will catch on with underwater photographers. As a specialized community, underwater photographers are looking for things in a camera that are quite often over-looked by topside photographers. Therefore, not all cameras are suitable for underwater use. When we decide to make housings for a camera, we look for a model that will match the specific needs of underwater photographers.
Once a candidate is selected, the next step is getting the camera. The large camera companies do not give housing manufacturers any special treatment and the best way to get a model ahead of time is by keeping a good relationship with the local Canon or Nikon rep. Usually we can get access to their sample model quite a bit ahead of the official camera launch. We can then take this opportunity to set it up on a laser scan bench and grab a 3D virtual model of the camera that we can load up on the computer and get going on the design work in earnest.
The 3D model is then integrated in the Computer Aided Design software (CAD). The rather complex software allows placement of the housing component in a virtual environment, which allows the engineers to then rotate the virtually created housing around and look at it from every conceivable angle.
Once satisfied with the design, it’s time to layout where the controls and buttons will be spread out and how they will access the camera’s controls. This part is critical and quite a few factors need to be considered:
• How vital is this control’s location?
• How complex is the mechanism to locate when placed in the housing?
• Is this going to conflict with other controls, and if yes, which one is the priority?
• Are there any specific needs to address such as space for the built in flash to pop up.
At this point, the design will gradually go from a simple wire frame shape to a photo realistic rendering, such those you see from time to time from the various manufacturers when they announce future projects.
The final price of the housing is also a consideration. Complex mechanisms tend to be more expensive to manufacture and this needs to be accounted for at some point. Entry-level housings do not benefit from the same in-depth complexity as high-end housings at a substantially higher price bracket. Still, it is understood that every innovation that can be possibly implemented in a new housing design will be included.
The next step is to enter the data of the preproduction prototype into the Computer Numerical Control (CNC) program. The information being entered is really nothing more than a set of directions, sort of like numerical instructions, that tell the machines computer what work needs to be done. Once the programmer has uploaded the data, it will instruct the CNC machine, in this case a sophisticated one working on 5-axes, where and how deep to shave and drill out excess material from the provided block of aluminum.
Chapter 2: Machining
A modern machine shop will have various machining tools at hand to fulfill the multiple tasks associated with such complex shapes. The top of the line machine has got to be the 5-axis CNC machine. While the more traditional 3-axis machine will work on only (you guessed it) 3 axes (up/down, left/right and front/back) the 5 axes one can actually pivot its mechanical head to follow much more sophisticated shapes and contours. That allows us to have a much smoother looking housing in the end, and very importantly, to shave of as much excess material in order to lighten up the final housing shell.
This whole machining process is so visually intriguing that I am sometimes caught gawking at the window for minutes, just like some poor sap staring at a washing machine at the local Laundromat. But hey, bite me, I like my job!
In order to have a complete housing we will need two aluminum blocks -- one for the front portion, and the other for the back. To start off, the machinist will insert a block of raw aluminum of a specific alloy into the machine.
Then cutting tools will be loaded on to the dispenser and the process will begin.
From this first procedure will emerge the internal hollowed side of the housing. The block will then be flipped over, the proper program will be loaded, and the necessary cutting tools will be installed. From there, it’s a just simple “press enter” and the exterior details will be fashioned out. The housing now starts to resemble what it will look like when completed.
From this process comes a shinny, and in my opinion, stunningly beautiful piece that captures and reflects light in a way only a grease monkey like me can appreciate. Alas, this piece of art also has razor sharp edges that will rival some of those sharp objects found underwater. This sharpness will need to be addressed and this brings us to the next chapter, the treatment stage, in which the housing shells are prepared for painting and assembling.