In this section I will have a brief explanation of the different types of ballast systems I use in my kits.
The Kilo is the only cylinder kit I sell that uses the Propel (Gas) system. Propel is the gas used by companies like Testors to power their air brushes. It is in a liquid state while it is in the can, but becomes a gas when released from the can. The propel is transferred to the cylinder in a liquid state and stored in a small tank. The ballast tank is part of the cylinder and has vent holes in the bottom and a vent in the top that is opened and closed by the R/C system. When you open the top vent the air in the cylinder will escape through the vent and allow the water to enter the open vents in the bottom. The sub being heavier will now submerge. To bring it back to the surface the propel gas is vented into the ballast tank and with the top vent closed the water is pushed back out through the bottom vents. I would say this system is the most widely used in model subs today.
All of my other cylinder conversion kits use the RCABS ballast system. It stands for (Recirculating Compressed Air Ballast System). This system was designed by Dr Art Broder. The system uses the air inside of the cylinder to fill an external bladder to change the buoyancy of the sub. There is a one way air pump mounted inside of the cylinder. It is connected to the bladder by hoses that exit through the end caps. There is also a return line that is connected to the bladder and to a vent valve inside of the cylinder. When the system sits in it's basic state the rubber bladder is empty and the cylinder has air inside. When you activate the air pump the air in the cylinder is transferred to the bladder leaving a vacuum in the cylinder. The sub will now be on the surface. When you open the vent valve the vacuum in the cylinder will draw the air in the bladder back into the cylinder. The bladder now being deflated causes the sub to submerge. It is a very simple system needing no extra outside air of gas to operate.
The third system I use, this one being in my experimental 3.0 cylinder is called RCABS-R (R for reverse).
The idea for this system was given to me by Mr George E. Protchenko.
It is like the basic RCABS system but instead of starting with an empty bladder the bladder is full of air in the basic state. The air pump draws the air out of the bladder and deposits it in a pressure vessel. The bladder now being deflated the sub will submerge. When you want to surface the vent valve is activated and the pressurized air in the pressure vessel will enter and refill the bladder. This is another system requiring no external air or gas to operate.