Made a working submarine...

[Guest]

My boy and I built a submarine this evening.
(An assignment of his, which is due tomorrow morning)
The sub has to float, sink to the bottom of the tank and resurface.
He was allowed to use a hose attached to the sub, but I talked him out of that because he'd get extra credit if the sub performed it's task untouched and untethered.
We had about five or six failed attemps, but decided to try just one more time...
Here's what we did;
Took a water bottle and cut it in half, then cut a section out to make the bottle about 6" shorter.
Taped 4 quarters to the bottom for ballast.
Drilled 4 equally spaced water inlet holes around the perimeter about 2 1/2" up from the bottom.
Drilled a hole in the cap to loosely hold a toothpick.
On the exterior side of the cap, we placed a foam float onto the toothpick.
On the interior side of the cap we placed another float onto the toothpick, which was to hopefully become a water shut off valve.
We then screwed the cap onto the upper section of the bottle and placed two Alka Seltzer tabs on the lower end of the toothpick.
(He thought it was pretty neat, drilling holes in the seltzer tablets)
Once secured, we the attached the lower half of the bottle to the upper half of the bottle with duct tape.
We filled up the sink, held the sub in the water and waited for the water level to rise close to the level of the four holes, then stood back to see what happened....
It floated, then started to sink and plumeted to the bottom.
The valve poped up an I thought we were home free as the seltzer tablets kicked into high gear.
Problem was, we had a leaky valve... Our sailors were running out of air!!!
After several attemps at trying different materials for valves, we went back to square one, gooped some petroleum jelly to the underside of the bottle cap, hoping that would solve our leaky valve problem.
Sink or swim, this was it ... as it was getting late.
You should have seen the look in my kid's eye when his sub popped back up to the surface!
He was pumped!!!
You should see my kitchen.

[bledsoe3]

That's a cool experiment! It's great to see kids expressions when they are excited about something.

[mikeschn]

ha ha ha... I can see your kitchen...

But it sounds like it was all worth while...

Mike...

You should see my kitchen.

[Chip]

Dean,,, Who's experiment did you say this was,,,??? sounds like daddy had fun too

[Archer_1]

Dean,

Post a picture of your fine, seaworthy vessel! Hope your boy gets an 'A'.

I can't quite picture the valve as you describe it.

[bledsoe3]

Dean,,, Who's experiment did you say this was,,,??? sounds like daddy had fun too

Chip, We dads tend to get involved and forget who we were doing it for. I guess it's just the kid is us.
Dean, ever here this one? Daddy it's my turn.

[Guest]

Dean,,, Who's experiment did you say this was,,,??? sounds like daddy had fun too

Chip, We dads tend to get involved and forget who we were doing it for. I guess it's just the kid is us.
Dean, ever here this one? Daddy it's my turn.

You shoulda seen at the pinewood derbies...

I can't post a picture, since he took it to school... but I drew this diagram from memory.

Once we gobbed on some Vaseline to the top side of the lower float, the sub reserfaced. He was amazed at the gases jettisoning out the four inlet holes. I doubt he will get an "A".
I was quizing him on density, mass, volume...
Stuff which related to the project.

[Archer_1]

You doubt he'll get an 'A'??? Jeez, his school must have some pretty high standards.

Thanks for the diagrams; I was envisioning the bottle lying on its side in the water for some reason.

[Ira]

Boy--I gotta be a lousy father. I would NEVER be able to figure this stuff out.

But since we're talking father/son, gonna hijack a little here:

Younger boy is now in the Cub Scouts. Wife is taking him with the troop camping this weekend. I'm staying home because my older boy, 14 (autistic) can't deal with the cub scout troop situation in tents, the whole social situation, etc., but ...

Once The Crab is ready, we're gonna have a nice, comfortable way for ALL of us to make these trips, but I know I'm gonna have to deal with some political crap because it's "not fair" to the other scouts that we'll be camping so "high on the hog."

Is that MY fault? Did THEY spend 3 plus grand (and counting) to build this thing? Did THEY have to see Gorilla Glue get stuck in Scott's hair? Did THEY have to spend 50 bucks a week on bandaids? Not to mention enduring the never-ending debates here regarding poly glue versus TITEBOND!?

But getting back to that submarine:

Dean--did you ever try that with a beer can?

[mikeschn]

Ira,

You should have been in politics...

Mike...

[Guest]

Ira,
Didn't try it with a Bud can...
It was one of those, waited 'til the last minute to ask Dad for help things...
I was suprised myself that it worked.
I knew if I didn't get the ballast too heavy, that two tabs of Alka Seltzer would refloat it.
My design on the foam floats was pretty weak. (closed cell glazing tape wound up onto itself)
First thing I did was take a full bottle of water, add two tabs, close back up and see what happened... (The bottle got real hard)
Next we worked on the inlet holes and floats to make sure the escape valve would close once the vessel was sunk.
Then came the tricky part... refloating it.
We lost about 5 or 6 crews because the valve didn't seal tight enough to keep the gas from escaping. (It just sat on the bottom with bubbles coming out as our crews perished)
It wasn't until we tried Vaseline on the top side of the lower float, that we had a good seal on the valve.
By then it was too late to build a bitchin' one. (Even though we had talked about turning the bottle sideways, painting it yellow and mocking up something likened to the Yellow Submarine)

[Classic Finn]

Ira,
Didn't try it with a Bud can...
It was one of those, waited 'til the last minute to ask Dad for help things...
I was suprised myself that it worked.
I knew if I didn't get the ballast too heavy, that two tabs of Alka Seltzer would refloat it.
My design on the foam floats was pretty weak. (closed cell glazing tape wound up onto itself)
First thing I did was take a full bottle of water, add two tabs, close back up and see what happened... (The bottle got real hard)
Next we worked on the inlet holes and floats to make sure the escape valve would close once the vessel was sunk.
Then came the tricky part... refloating it.
We lost about 5 or 6 crews because the valve didn't seal tight enough to keep the gas from escaping. (It just sat on the bottom with bubbles coming out as our crews perished)
It wasn't until we tried Vaseline on the top side of the lower float, that we had a good seal on the valve.
By then it was too late to build a bitchin' one. (Even though we had talked about turning the bottle sideways, painting it yellow and mocking up something likened to the Yellow Submarine)

A Lost Crew??? No rescue efforts attempted? Hmmm sounds like a Greek
Submarine Build Attempt.....

Sounds like a great project Dean...And your son gets high marks with it..
Thats a real father and son project... real nice..
My oldest son of 13 made a teardrop model in woodworking class..
I,ll have to get some pics of it... 1st he built a model of cardboard, then
for the aluminum siding he cut up empty soda cans... quite nice actually.

I think it has rubbed off onto him.. he,s looking at the photos here as well
quite often...He even knows of the name MADJACK - Mike and Dean....
real cute to listen to his stories and ideas about teardrops and old trucks..
Its valuable time spent together with your kids.. I enjoy it to the fullest..

LIL FOLKS ARE PEOPLE TOO
VERY MUCH LIKE ME AND YOU.... sings Charlie Daniels

Classic Finn

[doug hodder]

Does anyone remember back in the late 50's...if you sent in 25cents, can't remember the exact amount...less than a buck anyway... to Calumet baking soda...you got a plastic submarine....load some baking soda into it and put it in the tub and it would dive surface etc....cheap fun...but then I used to make steam rollers rubberband powered out of wooden spools....many moons before an x-box....Dean...maybe we can make a bingo stick at the Redwoods Gathering...your son will get a kick out of that and amaze his friends...good job on the sub!!! Doug

[Larwyn]

Alkaseltzer and school.

Brought back memories of what half an alkaseltzer would do when droped into the ink well.............

Great work on your little submarine there. Hope his teacher gives you a good grade on it.......

[Chris C]

INKWELL ????? I didn't think anyone on this board was old enough to remember those. And yes, I remember explicitly what an alka seltzer does in one. What a mess..........and then what a pain in the a$$ after the teacher caught us! Thanks for the memory, Larwyn.