Is RCABS extinct?

[redboat219]

Is anyone still using RCABS?

[Subculture]

Plenty of systems operate on a recirculating compressed air cycle. Piston tanks sealed tank water pump, flexible bag water pump system etc,

The system using a small air compressor and bag was largely democratised with the kits that Dave Welch used to produce, obviously that came to a stop with his passing.

[He Who Shall Not Be Named]

Plenty of systems operate on a recirculating compressed air cycle. Piston tanks sealed tank water pump, flexible bag water pump system etc,

The system using a small air compressor and bag was largely democratised with the kits that Dave Welch used to produce, obviously that came to a stop with his passing.

As has the variable ballast tank, gas-saver mechanism and SAS. Times and flavors change.

One thing that has stood the test of time: The WTC concept.

[redboat219]

Surprised you mentioned the SAS.

[Subculture]

The flavour of the month tends to coincide with what is commercially available. Very few will willingly go down the path of scratch building their own dive systems, it still happens quite a bit, but most will use commercial items, or copy the designs.

There was a point in time around the turn of the millennium where choice was extremely limited, and modellers either had the option of secondhand systems, scratch build or find another hobby. That brought about a bit of creative thinking, but naturally it did narrow down the range of participants.

[redboat219]

The flavour of the month tends to coincide with what is commercially available

so I guess right now it's pumps, either gear or peristaltic coupled to a vented tank or bag/balloon.

[bwi 971]

I went down this path, and it was quite interesting to learn along the way. Space reservation turned out to be the most challenging part for me.

One downside of gear pumps is that they allow backflow when not running. This means you need to take preventive measures, like installing a solenoid valve or some other gizmo, to avoid your ballast tank slowly filling up when surfaced. Gear pumps can also generate quite high pressures, so it’s important to install pressure relief valve(s) to prevent your endcaps from blowing out or damaging other components.

Peristaltic pumps, on the other hand, don’t allow backflow, but their downside is a very limited output volume. This can be a drawback depending on your submarine’s size and ballast system requirements.

Grtz,
Bart

[Subculture]

I found the little orange gear pumps tend to max out at around 40psi (about 3 bar), certainly enough to cause issue if your tank isn't built well. Other makes of gear pump may go higher, but not use them. Peristaltics can push well beyond that as they effectively have no slip.

I think all systems have their pros and cons, and you pays your money and takes your choice.

[rwtdiver]

At one point I designed a syringe type ballast system for my Alfa boat, and set about designing my own WTC.


Video link

https://youtu.be/WiuponqZ90Y

I scratched built the WTC and installed the syringe type system. It became a little bit complicated for me, and I never got it working for my Alfa.


This the remnant of that system and I am thinking about giving it another go around in another boat!?

Rob
"Firemen can stand the heat."

This whole project was based on a total experimentation. I had no idea if it was sized properly for the Alfa At the time after building the WTC and adding this syringe contraption I discovered I did not the enough room for the drive motor. Might be now I could use a brushless motor and updated electronics on the ballast system and make it work. Again It would be another experiment.

Rob
"Firemen can stand the heat."

[Rick Teskey]

I am still using rcabs ,simple, easy does the job I switched over after propel squirted me in the face charging against a frozen Schrader valve stung like a sob swapped system out then and there
Art Broder was the first fellow to show me his system.

[Subculture]

Here in the UK a lot of model submariners built kits by John Darnell, and they tended to use a bag with a small oscillating steam engine converted into a basic air pump with a small geared motor, that pumped the air from the bag to a reservoir tank then recirculate it back to surface. The old steam engine used to be a bit leaky, so a lot of modellers swapped them out for a tyre inflator compressor. When those little diaphragm pumps hit the market, it made compressed air systems easily adaptable to smaller boats