Aluminaut Research Submarine 1/96th Scale

[trout]

The big question for me is will this piston ballast tank seal the thread or leak like a sieve? Today, I got a small window of time to test it out. I connected another syringe to the ballast tank by means of a vinyl tube (Thanks Emergency Care) filled it with water and let the ballast tank fill and empty multiple times. I pressed on the attached syringe's plunger to increase the pressure and created a vacuum by holding the plunger and was able to stall the motor, but the result is..........NO LEAKS! The piston travel limiter is now attached to the motor housing and drying as I type. Maybe a video or some pictures in the next several days.

The tank is small and I weighed the volume of water it holds ~3.5 grams. For a sub this size that should be significant enough, what do you think?

[He Who Shall Not Be Named]

Sounds like that hurdle is behind you. Should get your boat from designed waterline (lower edge of superstructure) to completely submerged. Will be fun to see how much utility you get from that vertical thruster up on deck (the people blender).

[Scott T]

If this model had a wet space in the hull you could leave the tube and suringe attached
and fill it with dish soap to lubricate the plungers. Congratulations on the successful test.

[trout]

David we will see how it will all works out. Thank you Scott. Did a little video while son's pinewood derby car was drying.

[crazygary]

Mornin', Trout!!
Wow!! Definitely looks like a "keeper"!!
Nicely done.
Thanks for the inspiration!!
K.I.S.S. is the only way to go!! Bravo, buddy!

Crazygary

[trout]

Thanks Grazygary,
Tonight, working on the molds for the light bar. Will post when it is done.

[crazygary]

Very cool, buddy!
You Da Man!!
Appreciate the excellent photo coverage on your build! Makes all the difference in the world!!

[He Who Shall Not Be Named]

Ditto to Gary's comments. You are scary good, Tom. I hate you! At some point (as those cavities within the tool get tighter of section) you'll only get a resin fill if you resort to vacuum and/or centrifugal casting techniques. I'm seeing your work with the piston tank leading to a 'hovering' sub-system for the bigger cylinders. Cary on, sir! You carry to the Torch well.

[trout]

Thanks guys! David, I do have an idea for a proportionsal ballast system. Pinewood Derby is out of the way, so a little time on this idea might be available.there will need to be some parts for the lathe that need to be acquired. I have the design and concept on paper, it is getting it in hand that will be the challenge.
Crazygary, don't just steal the piston tank as David suggested on another post, but please improve on it!

[crazygary]

Not to worry, my friend!! I have absolutely no intention of
bagging on your design!! That would be most uncool!! All the "Kudos" are yours!!
A "job" well done and carried off with flying colors!! Nice!!

I do, however, have a question! Is there some sort of formula to determine how big a volume of air is needed
to surface?? I'm sure it has something to do with the overall weight of the sub to begin with!!?

Would appreciate any hints!

[He Who Shall Not Be Named]

You need to know the weight of water to take on board. That weight is equal to the weight of the water displaced by the above waterline structures. Period.

[trout]

I wish i could give you some formula (I have no doubt there is one), but I am not there yet mathematically. With the tank flooded, I will trim the sub ever so slightly negative. Then what ever lift I get when the tank is emptied is the lift I get....pretty technical huh? not.

[He Who Shall Not Be Named]

What is the volume of the above waterline structure? Working that out is the hard part if you're going the math route as you usually are not dealing with the classic geometric forms. Or, you can go the original Archimedes route: top off a tub of water, with it situated over a catch container, invert your model and stick it into the water to the waterline. The displaced water runs over the edge of the tub and is collected in the catch container below. That run-off water is the amount of water your ballast tank must hold. In either case, make your ballast tank volume about 110% of whatever you determine the amount to be.

[crazygary]

Great tips here, Gentlemen! Thanks a bunch!

David! Your Archimedes principle sounds pretty straight forward, but, I'm reading it as if my ballast tank should be water filled?? Yes, No?? If so, don't know yet how I can fab up some sort of valved inlet and outlet. Won't be much room for sliding valves inside a 1" diameter cylinder!! Any suggestions?

The Virginia I'm planning to build, I believe, will be a "wet hull" boat. A better portion of the hulls interior will be filled with the wtc. So, first I'll have to build the wtc, with all the necessary components, install it, then perform the
"inverted-water-displacement" trick?? Sounds logical, for a non-Vulcan!! ( With all due respect to Mr. Spock!! Hah!)

Ennyhoo, as mentioned previously, I'm still in "looky-loo" mode, but hope to get her off the ground, so to speak, within the next couple of weeks! Still involved, unbfortunately, with the "4-letter-word" thing: WORK!! P'tooey!!!!!!!!! So, modeling time is confined to weekends, and, naturally, at the whim of my beloved wife, who has managed to amass the "honey-do" list from hell!!!!

But, I digress!!

Thanks again for input, guys!!

[He Who Shall Not Be Named]

Honey-do's first, then play. You know that! You do the Archimedes trick first, to determine the volume of water needed -- which drives the length of your WTC ballast tank. Duh! Machinists!