Expoxy Potting New Camera


#1

Has anyone tried the various optically clear epoxies on the market potted over a camera lens? I’m looking to pot the new OpenROV camera and i’d be interested to know if anyone else has done this yet.
My plan is to make the camera capable of handling 216psi at a depth of 500 fsw, thoughts?

thanks!
-Erika


#2

Never potted a camera myself- but for the external light cubes we use Loctite EA E-30CL epoxy, which for its manufacturer’s intended use is for bonding glass. When cured properly, it is optically clear. ‘Properly’ by the potting method I have devised over time is as follow:

  1. Use a heat gun to warm up the epoxy. If you are using an injector nozzle be sure to keep the epoxy tube right side up, with the nozzle on. As you heat it up make sure the epoxy tube doesn’t warp, if it starts to flex just lay off the heat a bit. But you really want the individual parts (unmixed) to be be warm all the way to the core of the tube. Doing this in an upright position allows trapped air to escape in your first few pumps. As it heats up, the viscosity drops, and it flows with much less effort. The first few pumps should be disposed of, as lots of trapped air bubbles will come out at this time.

  2. Additionally, warm up the thing you are about to pot. I generally find it better to use a lower heat setting, passing warm air over a surface for a longer amount of time vs. a hotter air shorter time.

  3. Allow it to cure in a warm environment, it can get cloudy if the temperature is not consistent throughout the entire process.

However I haven’t potted a camera, only other components. Hope that helps!


#3

Hey Erika,

This is a really cool idea, I’m pretty psyched to see if it’ll work. I think Nima’s right with the EA E-30CL, though I think an issue you may run into is heat generated by the chip on the back of the unit, which is (I believe - EE nerds please correct me if I’m wrong) doing the video compression.

If you’re going to pot the whole assembly, I think it might be worth it to put some metal pieces in the potting that are exposed to water, for cooling. Something like this:

Where the metal is close to or touching the chip surface.

Either way, (and I apologize if this is something you already know) epoxy has a hard time sticking to polypro, so that’s a good candidate for making your mold, if you just want a camera in a block of epoxy. Also, potting an assembly this large without some good heat transfer (like the metal fins) could result in bricking your camera, because epoxy releases heat as it cures, and cures faster at higher temperatures, so big blocks get super hot in the middle as they go.

Can’t wait to see the result when you try this!


#4

We first glue a gopro underwater lence to the camera lens and than pot the camera in a 3d printed camera house. http://stinger.no/cases/nano-rov


#5

We have good experience with 3m dp270 with regards to potting electronics. Other epoxy resins have damaged components and we think this is related to the generated heat when curing.


#6

I fear you will alter the camera focus. See if you can do a test with some removable material first.


#7

Hi Erika,

What follows is our recent experience with potting epoxies. We are potting high powered LED’S in the range of 30 to 50 watts for the purpose of attracting fish at night. We’ve used 3M DP270 and were disappointed with the results. Currently we are trialing an optically clear epoxy that is performing beautifully. I have not potted cameras but I believe the current epoxy we are using would work well for your application. It’s manufactured in Canada by Polymer Composites and is called MAX CLR-HP available on ebay. The major downside is the costly shipping.

Have a great day,

Justin,