Subject:
|
RE: submersible, ballast, depth sensor
|
Newsgroups:
|
lugnet.robotics.handyboard
|
Date:
|
Wed, 28 Jul 1999 14:29:08 GMT
|
Original-From:
|
Barry Brouillette <barry@STOPSPAMMERSsgi.com>
|
Viewed:
|
767 times
|
| |
|
|
There is a whole community of Radio Control submariners who have extensive
experience that you could make use of. If you want it to act like a true
submarine with diving planes etc. you should definitely use their knowledge
base. It is much harder than it would appear. A few links:
http://www.wolfsong.com/SubCommittee/
http://www.primenet.com/~kndbrd/rcsubfaq.html
I once built a small submersible using a veterinarians syringe as the
balast tank. A gearmotor drove a long threaded shaft to move the piston in
and out. The tip of the syringe was connected to the outside of the sub and
the other end was open to the inside of the sub. When the piston moved into
the syringe it pushed water out and decreased the air pressure inside the
sub slightly. When the piston came back in it would suck in water and make
the sub heavier. Something like this could be done with almost any smooth
tube and a corresponding piston with an O ring seal. The trick is that if
you go very deep you may exceed the motors capacity to push. The nice thing
about it is its simplicity and no requirement for compressed air.
Barry
-----Original Message-----
-----Original Message-----
From: Andrew Harris [mailto:mail96928@pop.net]
Sent: Wednesday, July 28, 1999 9:02 AM
To: handyboard@media.mit.edu
Subject: Re: submersible, ballast, depth sensor
>
> Hi!
>
> I planned to build a sub myself about
> two years ago but couldn't find the time to build it. What I have to
> offer are some thoughts.
>
> Fortunately a submersible needs lots of ballast, so you can stuff it
> with lots of batteries and gear.
> So my plan was to use a $10 air compressor (the sort you can buy at
> service stations to fill your tires) to move air from a bouyancy
> tank (with a hole at the bottom connected to the water) into a • reservoir
> to sink and to let it flow back through an
> electric valve to rise. This way the only refueling you need is
> electricity. So you don't need to refill the canister from time to • time
> which means maintainance on land.
I'm curious; what is the difference between the "buoyancy tank" and the
"resevoir"? I'd think moving air from one tank to another won't
actually
affect buoyancy. Am I missing something?
> My favorite methode would be to use an electric piston system to move
> water in and
> out of a large cylinder (about half a liter). The other side of the • cylinder
> (the air side) must be connected to the interior of the sub. This way
> you would change the pressure inside the sub. Or you could say you
> change the overal volume, hence the bouyancy.
That's interesting; but difficult, right? Ensuring a watertight seal
around
the piston even under various pressure differences is really hard. Can
you refer a specific piston system?
> I planned also to build some kind of automatic emergency float system.
> Nothing else than some ballast to drop when the batteries run too low
> OR a preset time has elapsed (the latter could be a mechanical • solution
> using a modified kitchen alarm clock).
That's a good idea.
-andrew
mail96928@pop.net
|
|
1 Message in This Thread:
- Entire Thread on One Page:
- Nested:
All | Brief | Compact | Dots
Linear:
All | Brief | Compact
|
|
|
|
