Pneumatics release method
 

How do the pneumatics release the compressed air?

Do they build up a certain amount of pressure (i.e. 1/2 of the maximum value) and release that or build it up completely and only release 1/2 of the built pressure?

Links to a manual would be helpful

Re: Pneumatics release method
 

The pneumatics build up the entire pressure that is allowed in that area. Each cylinder has a certain volume of air that it uses every time it operates. When a vent valve is opened, air under pressure rushes out, allowing enough pressurized air to come in on the other side of the cylinder to fill that volume and move the piston. Assuming that the system doesn't refill, eventually the pressure won't be enough to move that volume of air into the cylinder, and the pneumatics won't work any more until they're filled up again.

Typically, on FRC robots, teams will fill up their system with as much air as it can hold, and then fill it up again once it gets below a certain level, so that the cylinders will always fire.

The FRC pneumatics manual would ordinarily be available right now, but seems to be down. You could try finding the 2009 one, bearing in mind that things may change a bit from then to the 2010 one.

Re: Pneumatics release method
 

Well, you could be talking about alot of things here. Do you mean;

1. Solenoid releasing pressure to a cylinder
2. Pressure switch controlling the pressure in the accumulator tanks
3. Pneumatic purge valve (Releases all of the air in the system)

EDIT: Eric pretty much covered it

Re: Pneumatics release method
 

Pneumatic purge valve

Re: Pneumatics release method
 

It's that little brass valve with a not-quite-triangular twist handle on one side. If the handle is parallel to the tubing running into the valve, you either have no air in the system, or will have no air in a couple of seconds. If it's at right angles, you'll have as much air as you are legally allowed to have, or you're filling the system. (Be warned, you don't want to have it open when you're trying to fill the system before a match. It's bad...)

Re: Pneumatics release method
 

Camper,
This is more of a question of volume vs. pressure. You can determine the volume of air stored in the Clippard tanks at 120 PSI. When ever you send pressure to an actuator of a moving cylinder, it also uses a volume of that stored air. It is easy to determine the volume by noting the diameter of the piston and calculating it's area then multiply that area times the length the cylinder travels. When the valve that supplied the air is closed, it vents the air in the cylinder to atmosphere. If air is added to the opposite side of the cylinder or if the cylinder is moving something heavy or restrained by springs, then the return will be quick. If you do not use one of these return types then the cylinder will not move.
Does this answer the question?