Acrylic underwater housing

Discussion
1

Hello all,

I was thinking of making an underwater (up to 30m) housing for a Raspberry Pi Zero, camera module and battery using layers of laser cut acrylic and a powerful glue to hold it all together. I was going to make one of the tops and one of the ends removable for getting at the camera and being able to replace them if they get too scratched (made watertight with double o-ring seals and screws. The idea is to make a underwater camera trap / time lapse camera.

Does the acrylic sheets and glue sound too crazy to work?

2

I would use something with solid walls rather than glued layers.

3

Clear acrylic tube with bolted on disks of acrylic with rubber gasket seal at each end?

Depend how you fit it in, but if the camera lense was pressed up against the inside of the tube wall you may get some image distortion, but it might not be too much. Even if it is there’s software means to correct that afterward. Or, put the camera at one of the flat cap ends of course.

Get a tube with very thick walls (ebay?), you’ll be able to tap a screw thread in it in several places and screw down a thick cap with rubber gasket seal. You could laser cut the acrylic cap and the rubber to whatever size tube you can get with thick enough walls.

Do you need a button or will you set a timelapse going before you seal it in? I feel the second option is going to be a lot easier to engineer…

4

If you could make it entirely wireless with inductive charging and maybe turn wifi on via a reed switch then you could seal the thing fully.

Solvent weld doesn’t just glue it actually melts the two materialls back into one again.

I’d assume that a single plastic tube would be stronger if the gaps were not there, than if they’re sealed up with glue or other materials.

5

We’ve made 40-50L water tanks for work out of acrylic and glue. I’ve never seen one break.

30m underwater would be more force but it would be pushing the plates together not apart, its worth a try

6

30m is potentially 60 psi, not insignificant amount of pressure. I’d go for mechanical seals rather than welds (like @pip says)

7

Thanks all for your . This one will just be a turn on, then put in the box, so no buttons required. Guessing the things like this (http://www.divingmachines.com/Diving_Machines/Housings_files/plasticama.jpg from http://www.divingmachines.com/Diving_Machines/Housings.html) are moulded acrylic rather than welded. Will have a look at the acrylic tubes idea.

8

If you look at OpenROV, they use a cast acrylic tube with laminated laser cut end caps. Instead of using the tube in a transverse orientation, it would be feasible to mount the lens looking out of the end of a single thickness portion of end cap.
I would also consider an external acrylic cover which can be mounted a small distance from lens, allowing water between, so that it can be changed if scratched.

Just a lateral thought. I’m sure you’ll manage it.

Don’t forget to build in dehumidifier strips.

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