Valve advice

[u-869]

Hi all, I am fairly new to RC submarines, having spent most of my time building large scale RC ships.

I have currently planning a large scale type XXI for a client, and am considering the compressed air ballast system. (The sub will be somewhere in the region of 8 ft long).

Could anyone please help with my ignorance of valves? I would like to know your recommendations (and supplier info if at all poss), for a vent valve, blow valve, one way valve and air intake valve.

Many thanks

[carcharadon]

Re: Valve advice

At one time I had a 7ft Nautilus set up as a static diver. I used a fuel injector as a valve. Operating voltage for the FI was on the order of 5 volts but it would work with 12. It was in the wet so the water probably kept it cool. I used both liquid refrigerant and compressed air at about 140 psi. It worked very well. With the compressed air I could only fill the bladder about 3 times and probably about 10 times with the liquid refrigerant.

[u-869]

Re: Valve advice

Hi Charcharadon, thanks for the reply.

This sounds interesting - do you have a diagram/photo's at all pls, showing the set up?

Thanks

[carcharadon]

Re: Valve advice

Sorry no photos.
This is the sub and it was quite a while ago that I had it set up as a static diver.

http://www.youtube.com/watch?v=Sva4FPOnU80

I switched back to dynamic diver primarily because I couldn't see the sub once it went under.

The system was real simple. On one channel it would simply open the fuel injector and gas would fill a bladder which was actually a rubber air spring from JC Whitney. It had a hole in the bottom and the incoming gas would displace the water and it would attain buoyancy. To displace the gas a bilge pump would force water into the bladder displacing the gas or air and the sub would sink.

One-time I had the sub in about 30 foot of water and I would just let it sink to the bottom, sit there for a while, and then bring it up. This worked great and I could always tell where it was coming up by the leading bubbles.

The only problem with this setup was that once underwater I couldn't see what the sub was doing. If I could see it then of course I could make adjustments.

As a dynamic diver I always know that it is buoyant and I could judge how deep it is by the amount of time I use the down control and also the angle at which it submerges. So for my particular situation I abandoned the static system.