Wednesday, August 10, 2011


For the past few weeks I've been struggling to think of some way for hamsub to dock with hampture and safely deliver hamsters to and from it. A docking collar was out of the question because it would require some kind of motorized system to pull the two docking rings tight against each other, motorized doors that would open, but also shut tightly enough to keep water out, and all of that would need to be radio controlled. It just wasn't feasible for me. Neither was an airlock system using doors, since hamsub requires an air tube. That's when this design occurred to me:

Fig. 1: Docking chamber with a moon pool in the bottom starts out full of water. This way hamsub can navigate up inside of it and come to rest on the part of the floor that wasn't cut away to make the moon pool.

Fig. 2: A separate air pump just for this one purpose is turned on, forcing air into the docking chamber, pushing the water out until the waterline has dropped down to the moon pool and the chamber is empty of water. The hamster is now free to climb out of the sub and up the tunnel into Hampture.

This is drastically simpler, doesn't risk catching the hamsters in the closing doors, and requires little in the way of modifications to hamsub. I am planning to make the docking station its own separate habitat, connected to the others by a long, flexible tube.

And no, the hamsub is in no danger of tipping over for the same reason a hot air balloon doesn't tip over; The very buoyant part is on top and the very heavy part is hung underneath it. This keeps it stably upright in water despite any attempt to tip it.

Major renovations underway.

So, while installing a ridged climbing tube between the upper and lower floors of the habitat tower, I learned a hard lesson about sealant quality; Upon reassembling the tower I found I had run out of marine grade silicone sealant, so I used something purporting to be just as good, a transparent goo that I immediately discovered was complete crap at waterproofing. Upon test-submerging the reassembled habitat (without the hamsters inside obviously) it slowly began taking on water in the recently reassembled section. I took it out, checked for leaks, added more sealant, waited another day for it to cure, but no dice. Leaks persisted, to the point that the habitat is now in pieces again awaiting proper sealant prior to reassembly.

However,in that time I happened across a few parts that fit perfectly together by pure coincidence. The domed lid of a frappucino (with the large hole for the straw) snaps onto the bottom part of a mini-DVD spindle, which serves as the floor. It does so very tightly, water does not get in. As for the large hole in the top of the dome, the small clear bubble from a 25 cent toy capsule happens to just barely fit when shoved through from below, such that it forms a sort of compound dome that is rigidly watertight without any glue.

This left me with a floor, and a compound dome. I drilled a hole in the floor piece and dremeled it out until it was large enough to stick a ridged climbing tube through and I'm now waiting for the marine loctite epoxy to cure. When the loft section is done, I will drill and then dremel out a hole in the cieling of the main living module and install the loft as pictured here:

You'll notice there's also a water bottle I've already installed. This is because I can't be sure whether or not permitting outside water in via the drinking tube, even through a filter, works properly. The Mk.III habitat used this mechanism but I could not be inside to test it while submerged obviously and the hamsters had a dish of water as backup in case it didn't, or in case they refused to drink even filtered lake water.

My main concern is that the internal overpressure would continually push air out *through* the drinking tube, permitting no water to get in through it. So even though the water intake mechanism would hypothetically offer unlimited drinking water, I've opted for a finite water bottle that I know for sure will work because it does not connect to the outside water and therefore won't permit any kind of pressure related shenanigans to occur. Plus it has a little plastic turtle floating in it so I can see when their water supply gets low. :3

Incidentally I have also replaced the kitty litter with planting soil from a garden shop. Bacterial action in said soil will continually process the hamster waste, and with the help of clover I've planted in the soil, it will metabolize it at a rate sufficient to prevent buildup. This means I will soon be able to leave the habitat underwater for as long as the food and water hold out, which (judging by their rate of consumption) could be a month or more. If I can prove to my own satisfaction that the filtered water intake works (by observing it in the test tank) then that could be theoretically extended to many months, assuming I put in an overly generous stockpile of food.

I've learned a valuable lesson about which sealants work and which don't. Now I can be confident that the Mk.2.5 habitat, once fully rebuilt, will not only sustain hamsters much longer than before without surfacing, but also be more reliably watertight than ever.

Saturday, August 6, 2011

Video: Patrolling Hampture in the minisub

Hampture 2.5

Hampture Mk.III is cool, but it's enormous and heavy, a pain in the ass to lug around. I need something more portable, but with enough living space for the hamsters for 24 hour missions. Enter: Hampture 2.5

It's a two story tower expansion to Hampture Mk.II connected by a transparent tunnel. This gives each hamster a private area and a means of exercise (for whatever reason when put in a circular enclosure, roborovksi hamsters will run themselves around the edge until tired out). They haven't yet figured out that they can reach the second floor, I may have to put in a climbing tube segment, but otherwise they spent the first few minutes thoroughly exploring the addition before going back to building a nest in the living quarters. Here's a video of the hams hanging out in the expanded outpost:

Wednesday, August 3, 2011

Diving helmet nearly complete.

Took ages for the silicone sealant to fully cure. I tested the helmet in the water tank, and it's 100% airtight. That was a pleasant surprise, I expected to have to add dabs of silicone here and there to seal spots I didn't get the first time, but no. Other than being messy (a lot of dust and crap got stuck to it while I was working with the sticky silicone) and needing the paint retouched (bits came off while working with the sticky silicone, that shit gets everywhere) and needing weights, it's ready to go. That's maybe 15 minutes of work, once I have the weights in hand, then a few hours for the paint to dry.

It doesn't look as nice as any of the consumer models, but then it's cheaper by a factor of 50 and it looks better than any of the DIY helmets I've seen online. I'm very pleased with how this is coming together and I can't wait to put it to use.