I’m looking for an inexpensive analog bullseye level to attach to an underwater installation using a BlueRobotics enclosure. I see really expensive ones for the oil industry (see link), but nothing even close to reasonably priced for a DIY project. I only need it to handle 40 meters. Any advice?
https://www.leveldevelopments.com/products/circular-levels/subsea-bullseye-levels-circular/
Hi @rangewider,
This is well outside my expertise, but if you’ve already got an enclosure can you potentially have one without a depth rating that’s located inside the enclosure? I’m not sure whether that’s suitable for your application, but presumably letting the enclosure handle the pressure would allow getting a much cheaper one.
From the linked one, note that this point
could be quite important. Light through enclosures and water can get bent in somewhat unintuitive ways (there are a few relevant resources here).
Thanks. Actually, the bullseye level is outside the enclosure. The enclosure holds the recording device but not the sensors. I place the sensors manually while on scuba and I need the use the level for the placement of the sensor array.
Fair enough. You may be able to make your own slim ‘enclosure’ with a couple of end caps, an o-ring, and some CNCing to make room for a non depth-rated bullseye level but, factoring in tool requirements and design time, that could end up costing the same or more than the expensive ones you’re trying to avoid.
Hopefully the community can post some alternative options/ideas, but I’m not sure how common an application like this is.
This is easy. Buy a cheap bullseye level and some two-part epoxy at a hardware store. Make a little form with aluminum foil, and pot the level in a cube of epoxy. Basically, you encase the level in a block of clear epoxy. This should get you down to around 300 meters.
Use this as your inspiration… 15 Month Epoxy Hot Dog Update GIF by Whathowwhy | Gfycat
OK, that’s basically brilliant (and I’ll be making a hot dog as well).
But how do I hold the level, level in the middle of the epoxy while it hardens? I can’t just put it on the aluminum foil directly or it will be open to the world at the bottom. Could I lay down a layer of epoxy and let it harden, then put the level down and layer another layer of epoxy to enclose it? Or will the seam between the epoxy layers be too weak?
Depending on the density of your level, you might also have to prevent it from floating to the top of the epoxy while it cures…
I like your two-step idea. You could lay down a 1/2" layer of epoxy and let it cure. Then attach the level to the base layer with tiny screws (or something). Finally pour a second layer on top.
Epoxy bonds to itself really well and is pretty forgiving to work with. If the first layer of epoxy is still slightly tacky, you can continue with the second pour as is. If it has fully cured, just scuff the surface with some sandpaper and wipe with acetone before the second pour.
Assuming your level floats on epoxy, here’s an even simpler process.
Travis. Thanks again. I’ll level with you. 
I think the first idea is better. If I start with a level table, then the top of the first epoxy layer will self-level. Then, when that hardens, I can put my level on that, screw it down and the level will be level. Then pour again. Even the top of the second epoxy layer will be level with the level and the level below.
If I push the level into the first layer while it is liquid, there is a decent chance it will tilt while as it dries.
I’ll post a pic when done.
Gotcha. Good idea! Please do post a picture! I’d drill small pilot holes in the cured epoxy for the screws (to prevent cracking).
Also, if the level gets catawampus during cure, you can realign it with the bottom by gluing a piece of sandpaper to a flat surface and dragging the cube across it by hand until everything is square again.
I like working with epoxy. Really useful stuff.