Looking for a pump - ballast pump that is

[anonymous]

Hello there,

I am trying to break into RC subs from planes and cars. have been working on a scratch built 1/96th ish Akula for the last few months in my spare time.
I'm getting close to done but I just cant seem to find one part... am looking for a 12 VDC water pump for the ballest system. I need one that pumps both ways when the polarity is switched, and it needs to be water tight when the pump is off(water cant flow in or out when pump is off).It wouldn't even have to be completely water tight, just so it dosnt leak out too fast under pressure from the compressed air in the ballest tank.


I'm going with a kinda reverse of the blood pressure cuff system. I have the cuff, but in a sealed ballast tank and I want to fill the cuff with water insted of air. I have looked all over the Internet for a pump that will work but I cant seem to find one.
I figger since you guys have worked with Subs a lot longer then I have that someone might have come across one.

any help would be great. thanx

[anonymous]

Here you go. A lot

Here you go. A lot of us are using these pumps on our RCABS ballast systems.

http://www.smartproducts.com/air.html

You want the AP-3P01

It's 6 volt but you can use a simple voltage regulator to feed 6 volts to the motor.

Here's a source for the blood pressure bladders too.

http://safetystore.com/medanerparts.asp

Here's another:

http://www.goldmine-elec-products.com/prodinf....mitem=2


I'm using this set up myself and it works great. You just need one servo to activate the micro switch that turns on the pump. When the servo is moved the opposite direction it make contact with a tire valve and the vacuum sucks the air back into the WTC deflating the bladder.

There's a lot of imfromation on this site and my own videos to watch showing this system in operation. Look around and you'll find it.

Hope this helps you.

steve

[anonymous]

Also you can get water

Also you can get water pumps from the same source as the air pumps but after trying this I will sick with the air system. It just works so well.

Steve

[anonymous]

Well, if I cant make

Well, if I cant make it work with the water then I will go with air. only thing that worry's me about the RCABS is what happens if your bladder pops or gets a leak? all of a sudden your boat dives for the bottom.

I know it is a remote chance...but I was a boy scout...and am still a Treky...so I like being prepared and having backups.
with filling the bladder with water instead of air then the worst case scenario with a catastrophic failure is that your boat's buoyancy will remain neutral. you wont be able to surface with the ballast alone, but you would still be able to drive it up.

[anonymous]

Well water filled bladders can

Well water filled bladders can leak too. And in some cases the bag is located right on top of the electronics. Not good either.

All my boats are trimmed so they will raise to the surface if wither goes wrong. Look at my Kilo video posted on this forum. It's a long download but it shows how I trimmed the boat to near hover but always it will return to the surface slightly above periscope depth when the ballast is full.

It's always a trade off. It just comes down to what you prefer for your system. Just trim it right and you should be fine.

Steve