Back in post #13, I offered an alternate wording to the rule that would be less restrictive.
In essence, what I'm suggesting is that any method of charging your tanks to 120psi which uses an otherwise legal Thomas or Viair compressor that would meet the 1.05cfm rule, includes a working pressure-based shutoff calibrated for 120psi (ie. the Nason Pressure Switch that we've been using for years) should be legal, regardless of its power source (robot battery or otherwise) and control system. You could even skip the requirement that it be an otherwise legal compressor, but that keeps it easy to inspect.
The simplest such system would be to wire the NC Nason switch in series with the power to the compressor through a fuse from a 12V battery with sufficient current capability. I realize that the reason this is disallowed on our robots is because the startup current of the compressor exceeds the current rating of the Nason switch and so runs the risk of failing the switch in the closed position. I agree that this exact configuration should be outlawed for that reason.
However, there is no reason that a similar pressure switch that DOES have the proper current rating couldn't be used in this way.
Alternately, the system which our cart had, which was:
Code:
2x12V Deep Cycle Marine Batteries used to drive the cart->
2004 IFI Control System->
Spike->
Thomas Compressor->
125psi Relief Valve->
120psi Nason Switch feeding the IFI Control System feedback->
Air line to plug into robot.
In essence, using our cart was like charging my robots air tanks using a compressor mounted on another robot that otherwise complied with the pneumatics rules.
We didn't, but you could even take it to the next logical step, and have the cart have more storage tanks on it than the robot, which you could pressurize ahead of time and simply dump into the robot, allowing for a nearly-instant fill (assuming you were smart about how you used release valves in the circuit).
My logic behind all of this is that since we all agree that we can change batteries after charging the tanks, the source of 12V power becomes irrelevant to the equation, provided its safe, and since we all agree that I can put my robot on the field with 120psi in the tanks, the method by which the 120psi gets there, and the time it takes to do it is irrelevant, provided its safe. The 1.05cfm limits how much air I can compress DURING the match to about 2.36ft^3, but the unlimited number of storage tanks and the fact that I can start the match with them pressurized to 120psi makes that 1.05cfm value unimportant to the total cubic volume of air I can use in a match.