Saturday, July 30, 2011

More progress on the helmet

As you can see it's now painted, and the spigot for the air hose is installed. I haven't put all the bolts back in yet because I still need to add sealant, just wanted it all in one piece for the photo. Should be done pretty soon!

Friday, July 29, 2011

Helmet progress.

Got all the holes drilled, all the cuts made, and the transparent acrylic view-panels are now installed.

Now I need to remove the panels again, clean it up, spray paint it, then install the weights and air spigot. I've already got 100 feet of air hose (It's just below the helmet in that photo) so once all that's done, we're ready to rock.

Tuesday, July 19, 2011

Now it's my turn.

In the 1970s, a toy called the aqua bell was available. It consisted of a thin, transparent plastic helmet weighted down with a collar section full of sand. It was supplied air from the surface via an electric bicycle pump. It was rated for 35 feet although one shouldn't really go deeper than 25 feet, as that's the limit before which your body will not saturate with nitrogen. Stay above that limit and the bends will not occur.

Unfortunately it's no longer available, and the only diving helmets you CAN buy start around $4,000. There's no good reason for this. They work the exact same way. Air is supplied from a surface compressor, and because it can freely escape out the bottom, the pressure inside self-regulates to ambient at all times. That's why it's not a struggle to breathe. It's the same way historical diving helmets worked before the advent of scuba, basically just a diving bell you wear over your head.

Why helmet diving? Because it's fun. Your hair and face stay dry. If you stick a radio inside and you're in shallow water, you can talk to the person watching over the pump (although a wired communication system would give better results). You can breathe normally, instead of sucking on a regulator. It's a bit like being in a space helmet, walking on the moon.

Today, helmet diving is still done. Unfortunately it's marketed as a tourist attraction and as a novelty for the wealthy and it's priced accordingly. Even though it's still just a weighted container fed air from a surface compressor, a consumer diving helmet like this one costs $4,000:

Here's a tourist attraction featuring similar helmets:

I consider it ridiculous that this experience is available only as a short duration tourist attraction or at an exorbitant, ridiculous price. There's no need. The same thing used to be sold as a toy for no more than $50! Surely something like this can be produced that everyone can afford so that ordinary people can experience helmet diving whenever they like.

Having done the math, my battery pack has around 336 watt hours of capacity and the compressor is 150 watts. That's 2.2~ hours of run time under ideal conditions. With AC conversion loss and the slight sulfation of the battery taken into account I can be guaranteed at least an hour of air. I'll know when it has run out because the bubbles will stop, and because I intend to have a stopwatch mounted inside the helmet where I can see it so I know how much time I have left. When I'm running low I can simply swim to the surface.

Please, no comments expressing concern for my health. Trust that I have a thorough understanding of the risks involved. I am certain this can be built, that it is safe, and that I will not be injured provided I stay in shallow water and have someone with me for safety. I would not put the hambros through anything I wouldn't also subject myself to, and if everything goes as planned, I will.

Here's the initial design for the diving helmet and a possible partial habitat/observatory I might also attempt following the completion of the helmet.

The helmet can be used in this configuration to get to and from the habitat, and also to explore the area around it. This configuration accommodates one person, so the supply of air is always sufficient, although because the rate of flow is enough to sustain 20 people by my math you could also bring a second person down to the observatory provided another such helmet. The real trick will be finding someplace with clear water deep enough to deploy this thing and getting it there.

If all goes well I intend to make a webpage pitching this idea as a commercial product. The goal will be a complete helmet diving system for under $100.

Sunday, July 17, 2011

Hamsub Mk.I is online.

There's good news and bad news.

Good news: The sub is neutrally buoyant, and stays upright in water. The design seems solid, moreso than I expected on the first try.

Bad news: The RC minisub that provides maneuverability is kind of crap. It has no ballast tank and relies on downward angled props to descend. This barely works. I can descend, but not without going forward a bit, and the minute the props stop spinning, the sub slowly ascends (which I can accelerate by reversing the prop spin direction, but the sub also moves backward, etc)

Solution: I've ordered a replacement mini RC sub that is much more expensive but which has a proper ballast tank, so it can greatly alter its own buoyancy on command. It also has stronger thrust, as you can see in the video that's something Hamsub sorely needs. The current thrusters struggle to make the sub turn against the influence of the air hose, which is as thin and flexible as it comes.

Here's a vid of the new RC sub that will soon be providing maneuvering capability for Hamsub Mk.II:

I expect the final product will also make an excellent low cost ROV simply by sticking a video camera inside the passenger capsule. For once, one of my projects has practical applications. Feels wrong somehow.

Saturday, July 16, 2011

Mission 1 complete.

Here's the video:

Everything went about as well as I could expect. Leaving them unattended overnight was nerve wracking but upon opening the habitat I found them sleeping piled on top of one another like nothing was amiss. They're now chilling in their tank awaiting new adventures. :3

Some things I want to fix for next time: The room 2 camera is pitifully low resolution, I apologize for this. I thought it would look better when I ordered it. I've already bought a higher resolution (640*480) replacement that is nearly as compact. I can't use a regular digicam because it takes up too much space, the hamsters need elbow room. But I think the new camera will be ideal, and if so I plan to buy more so in the next video we can get footage from every room rather than just two.

The battery pack read 20% when I found it, so longer missions are probably possible, but I think 24 hours is about as long as I'd consider deploying the habitat in this configuration. Eventually I'd like to upgrade the habitat and install it in a pond out back which I need to clean up a lot first. When that happens I can connect it to grid power and leave it down for a week at a time, with a livestream you guys can watch.

All in all, a fairly successful mission. And it began on the same day as the latest Aquarius mission, Neemo 15. Incidentally, by the official definition of aquanaut (one who lives in an underwater habitat for 24 hours) my hamsters are now genuine aquanauts.

T-minus 1 hour to mission end.

At 1pm today I'll be removing the habitat from the water, marking the end of the 24 hour underwater mission. Early this morning I dropped by the site, plugged my laptop into the webcam USB umbilical and was able to confirm that the hamsters are not only alive but appear active and healthy. Even so I was worried pretty much the entire time. No matter how much effort you put into the design, the safety system and whatnot, when there are lives in the balance you still feel irrationally paranoid until it's all over. I'm very tempted to remove them now lest something go wrong at the last minute but I want to see this through. Wait for the followup post, where I'll have cut together video from the onboard cameras for your review.

Friday, July 15, 2011

Today's the day.

In a bit, I'll be deploying Hampture Mk.III. Video will be available tonight and I'll be retrieving the habitat at the same time tomorrow. Wish me luck.

Saturday, July 9, 2011

Big update

I got my live culture of algae in the mail sometime back and it's been growing in the main jug ever since. Why buy algae you ask? As it turns out if you just scoop up some pond water you're getting tons of different organisms which in fact compete with the algae and impact its ability to efficiently generate oxygen. With a pure supply and a sealed jug (air is bubbled in via aquarium pump) I can ensure that the only thing growing in there is what I intended for.Once the main jug is sufficiently dense with algae I can pour some into each of the smaller bottles. Keeping a large healthy backup population prevents me from having to start over with the cultivation process if something happens to the bioreactor system.

Next, I scouted the precise location from which Hampture Mk.III will be deployed. As you can see there's an island near the center of the lake, with a steep dropoff into the water that should permit me to get Hampture in quite deep water without needing an absurdly long umbilical.Below you can see the fallen log which acts as a bridge to the island. This makes it inaccessible enough that I can confidently hide the surface support gear in the brush to one side of the island and feel fairly certain that it won't be found.Finally, here's the view from the island itself.Hampture Mk.III will be perhaps fifteen feet from shore and 7 feet down. It will be in water 8 feet deep, but propped up off the pond bottom on cinderblocks which will also serve as weights to keep it from floating. It's surprisingly difficult to keep any significant quantity of air trapped underwater, but I've factored that into the design. Once I have those weights attached, as well as a water filter for the drinking intake, it will be time to deploy.

Thursday, July 7, 2011

Hamsub begins development.

One of the most requested additions to Hampture has been a submarine of some sort as transportation for the intrepid hamsternauts. Toward that end, while I wait for an opportunity to install Hampture Mk.III in a nearby pond, I've begun work on a small single occupant submersible:

I intend to buy either an RC sub or ROV kit and use the components to turn this life support pod into a fully fledged submersible, with three waterproof motors and a small camera so I can properly steer it. The thin, flexible air hose will be woven into the same tether that supplies power and control such that the passenger has a steady supply of fresh air at all times. Here's the cockpit pod dealie in a tank of water. While air is being supplied I had a hard time getting bubbles to show up in the pictures.
If it's hard to tell, air is pumped in through the back and vented out through a small hole in the floor near the front window. This ensures that if there is a breach, any water that gets in will be continually forced out by the air pressure. A 15 minute test submersion with tissue inside came back dry, so I put Ratlas in there for about 10 minutes to see how he handled the snug quarters. He shredded the tissue, made a nest and fell asleep. :3

I'd love to figure out some way for a sub to dock at Hampture for food resupplying and transferring hamsters to/from the colony but the mechanism involved seems hopelessly complex and unsafe, so unless I discover that there's some professional quality premade connector that will do the job, Hamsub will be deployed from the surface only.

Bonus mspaint time: