Tuesday, August 16, 2011

Plans To Depth Test The Kodak Playsport

After our last diving trip, I've begun to wonder if I can depth-proof my little Kodak Playsport camera. The Playsport delivers terrific underwater videos, but is only rated to 10'. As far as I can tell, it only has two ways water could push its way past the seals, those being the ports on either side of the camera, shown below*.

These ports have coverings with internal seals. I'm thinking that the seals are what give out at depths greater than 10'. I think a layer of silicone sealant over these ports will protect them down to 30-45'. Once back at the surface with videos stored on the little guy, I can just peel the silicone off and voila! the camera is back to normal. What we need now is a test rig.

Enter the Gorilla Automotive VS401C tire valve stem and a bit of PVC pipe.

I think I can make a pressure chamber large enough for the camera out of PVC pipe, using a threaded end cap with plumber's tape on one end and a glued end cap on the other. I'll drill a hole in the threaded end and attach the VS401C there. Then I take the silicone-sealed camera, put it in the pipe, cover it well with water and seal up the pipe. I take the pipe to a gas station and put compressed air in it until it's at 3 ATM, which is equivalent to 60' of depth**. There's a simple PSI to ATM conversion, so the reading on the gas station air pump can be used to figure out where I'm at.

1 ATM = 14.7 PSI.

I let the thing marinate in the high-pressure water for an hour or two, check the pressure with a tire gauge before releasing and then I take it out and see how it worked. If it leaks, all I let in was fresh water. If it holds, then it's time to dive!

* - Our Maximum Leader provided the background on these photos. In the second one, you can see a little of the texture of her fur.

** - I might start smaller, say 2 ATM, but it kills me to have to spend another $0.50 at the gas station to run another test at 3 ATM.


tim eisele said...

One thing that concerns me is the other failure mode: crushing. A flat shape like that will have poor crushing resistance on the broad sides unless it has good internal bracing. I'm not sure how to test that and still be reasonably sure of having the camera survive a failure.

I suspect the LCD screen would be the main weak point under crushing stress. If it is 2 inches square, I'm getting about 180 pounds force on that screen at 3 atmospheres. Does it have any flex at all if you press on it? And are you confident that the camera would survive if you stood on it? If so, then go for it.

K T Cat said...

Good points, Tim. There's only one way to find out if it will survive ...

tim eisele said...

And then, after completing your testing, you can glue some tail fins on the test chamber and turn it into a water rocket!

K T Cat said...

Tim, I've thought more about this and I might reinforce the screen with some silicone as well. It's not like I need to look through it.

On the other hand, the thing is designed to be put in your pocket and has to survive a 250# man sitting on it on a folding metal chair or something like that. I'm sure it's been designed to withstand that kind of pressure on the screen.

Kelly the little black dog said...

Have you thought about putting it in something like this or that?

Kelly the little black dog said...

Then there is this.

K T Cat said...

Kelly, I thought of those kinds of boxes, but the Playsport has such spectacular optics that I don't want any extraneous plastic or glass between its lens and the water. I'm willing to take the chance with the thing to get good video.

As for the camera you showed, it's great, no question. I'm just not ready to shell out the cash for a new camera yet. Besides, this is a lot of fun!