EM
What is the displacement? So the tubes on the side are the batteries and soft ballast, right? Where is the weight? Also in the side tubes? If the weight is not in the keel, I'd think it might list too easy to when your existing the hatch in the top, envy if your not Santa :) Calculate your center of gravity for when your sitting on the hatch and make sure you not going to tip over, flood and sink. Have you considered a bottom hatch and a wet entry?
Do I count 4 thrusters? If the tail does not turn then do any of the thrusters? Or are you planing on steering only buy thruster speed and direction? I guess that can be done, but the control circuit will complex.
No doubt it will be a lot cheaper to build than a 1 ATM, but certainly no less fun. What materials are you thinking of using in addition to the acrylic?
Puerto Rico sounds like a great place to be building a sub. Are the walls close to shore?
With greetings from Oklahoma
Doug J
In a message dated 3/3/2004 2:48:51 PM Central Standard Time, emuller@naic.edu writes:
Thanks Doug for your comments, I can address a few of them right away:
I was actually planning to have separated ballast, i.e. a fore and aft
separation in the middle of the big ballast tanks.
The tanks on either side will be linked, so that rolling is not
generated by an offset boyant force, although pitch trim can be
fine-tuned depending on depleation of air tanks etc. Of course, I might
end up adding forward planes anyhow.
Getting in and out will be through a hatch in the top (not for santas).
There is enough ballast to give a freeboard of around 30-40 cm when
loaded up (I estimate). I envisage that the frame extending out that
back can also be used to attach boyant modules to fine tune ballast.
The V tail is simply a cop-out to try to get some stability mostly
against roll, since the projected resistive area against pitch and yaw
is minimised for a 45 degree angle in the V and is maximised against
roll. Since that part of the machine will be (probably) in more
turbulent flow a small x-section is preferable. Furthermore, It will be
entirely passive. Steering (yaw and pitch) is achieved by motors only. I
wanted to get away from dive planes because I live in puerto rico...
there are big walls that I want to be near and be agile at low speeds.
Since I am not using many heavy materials, that require much machining,
I hope that it will be cheaper than the typical 1 atm sub. I think I am
at more liberty to get things wrong and make a second attempt later on.
I expect that it will be quite iterative.
Thanks again for your comments! Please let me know if I am proposing
anything which cause your eyebrows to jump in
confusion/hysteria/contempt/disbelief!
EM.
DJACKSON99@aol.com wrote:
> Greetings EM
>
> Slick looking design. Not the metal can I'm building :) You might
> consider reducing the displacement of the cabin in order to decrease
> the amount of ballast required when you convert to dry? Maybe you can
> use 2 canopies, one for hydrodynamics and the second for the air
> seal. Since you're going to operate shallow you may want to consider
> that light entering the top of the canopy will reduce downward
> visibility due to reflection. You'll need a forward ballast
> compartment too, or you'll have to add dive planes and be more like
> the Bionic Dolphin (www.bionicdolphin.com
> <http://www.bionicdolphin.com>) And you need some way of getting in
> and out without sinking once you strap on the ballast needed to be
> dry, because your canopy opening will likely be below the water line.
> Maybe inflatable pontoons or a small top hatch? The v-tail is cool
> and low drag but they require a mixer that will complicate the build some.
>
> Thanks for showing your design. I look forward to seeing more.
>
> Doug Jackson
> www.jackson.parcabul.com/sub <http://www.jackson.parcabul.com/sub>
>
> In a message dated 3/3/2004 8:10:40 AM Central Standard Time,
> emuller@naic.edu writes:
>
> Hello folks,
> Due to pressure from un-named folks here (i.e. gauge pressure),
> and the
> upcoming threat of competition by scubatron (i.e. absolute
> pressure), I
> have also posted some images of design plans for an ambient, dry
> machine
> on moki.
>
> I suspect I will take the construction in a two-step process,
> firstly by
> building a wet torpedo-like thing and checking how it all works,
> construction methods etc. Then I will cover it over and blow all the
> water out to turn it into a dry machine.
> Comments please??
>
> EM.
>