[Biff]

The air things are simply fans and bags. As I said in the original post the pressure is less than 0.2 lbs. to get the force needed to more than lift a Robot, and a flap valve on the input tube to the bag is all you should need to hold air after the match. Fans that create vacuum have in the past been allowed as long a the power for the fan comes from a kit motor. The other thing that occurred to me was to power the fans from the main drive motors using a clutch or a dog mech that way you are not using a motor to only power the fan(s) the fan from a shop vac spins somewhere around 18 to 25 thousand RPM, so some serious gearing up is in order. The good news is it's not to hard to gut the motor part and put a pulley or two on the remains.
One example of a blower that we didn't use last year and one complete with Two Fp's driving it The one that made it to use was one Cim driving an 80 tooth pulley and then the smaller pulley on the shaft. Btw the Fp's drew about 30 amps each and the Cim ran at about 48 to 50 it didn't blow the snap action in the time of a typical match. That's why I suggested getting drive power from your main drive line.
Biff