I've been a recreational diver for the past six years. I live in Finland where there is not much to see while diving so I only do it on longer vacations once every one or two years. I have been building my own underwater housing for my cameras for ten years now. I'm not much of a photographer, instead my interest in building housings comes more from an engineering viewpoint.
The success with the DIY housings (4 by now) has been mixed during the past years but by now I have only destroyed one camera partly. On the other hand not one of the housings has been completely leak proof. Anyway, the housings have been evolving to more and more professional level by the years and now I thought it is time to share the current project with all of you as I have found only a very limited number of other DIY housing projects in internet. Maybe it's because everyone else values their time and gear too much to spend hundreds of hours of time in order to make a housing which implodes in 30 meters...
As a reference below is a picture of my previous DIY housing which is for Olympus E-PL2 with 20mm Panasonic pancake lens. The body of the housing is machined from a solid block of aluminum and the port is turned also of aluminum and attached with screws to the body. Front lens is acrylic and the back cover is 10 mm thick polycarbonate. This housing was made two years ago for a 3 month trip to Central America. There were problems with the back cover as the polycarbonate developed cracks around some threads. This may have been caused by the ethanol I used to clean oil from the polycarbonate. The 10mm thickness also was not enough for deep dives as the back cover bended visibly. Therefore I used the housing mainly for snorkling and for that it functioned pretty well.
Currently I am designing a housing for my E-M5 which I'm planning to use with Samyang 7.5 mm fisheye lens. Me and my girlfriend are leaving to the Philippines at the end of this month so I am starting to be pretty low on time to finish the project. The structure of t he housing is basically the same as that of the E-PL2 housing, however, it will have a dome port, hopefully better ergonomics and I dare to hope that this housing will finally be leak free. Below are two images from the CAD model in its current state. I guess I will have to finalize the CAD model during the next weekend in order to start machining the parts next week. I am planning also to print a 3D model of the housing to test the ergonomics before I start machining it. We'll see if I can make that happen. Oh, in case you are wondering how I get to use such nice tools as 3D printers and CNC machines, the answer is that I work at the machine design department of the largest university in Finland.
There are still a couple of problems to solve with the housing design. First would be how to attach the dome to the port. The dome is separated from an Ikelite 5503.15 dome port which was leaking from the glue seams between the plastic parts. I was planning to use an o-ring between the dome and the aluminum port but then there was the problem on how to press the dome against the o-ring. Also, I was worried that the dome might develop cracks when the pressure presses it against the aluminum. Therefore, I decided that it might be the best option to just glue the dome to the port with epoxy. This will make it leakproof and the glue also should distribute the surface pressure between the dome and the port evenly. The downside is that when the dome is glue, it can't be removed.
Another, still unsolved problem is the trigger button. As you can see in the image of the CAD model, it is still unfinished. If it is located above the trigger button of the E-M5 it will be quite far from the left side of the housing and my (short) index finger will not reach it easily. Therefore the button should be moved to the left somehow. The commercial housings have nice lever systems for the trigger but I'm afraid they will be difficult to manufacture in a DIY project. I would be glad if you could give me some ideas on how to solve this.
I will add more pictures and info later about the current state of the project and of course add pics when I start machining the parts. Now I will unfortunately have to start doing the work I get paid for.