[EricH]

The cylinders, as I read the rules, may not be used as storage tanks. Here is the main rule against it:

<R01> Energy used by FIRST Robotics Competition ROBOTS, (i.e., stored at the start of a MATCH), shall come only from the following sources:
 Electrical energy derived from the onboard 12V and 7.2V batteries
 Compressed air stored in the pneumatic system, stored at a maximum pressure of 120 PSI in no more than four Clippard Instruments tanks. Extraneous lengths of pneumatic tubing shall not be used to increase the storage capacity of the air storage system.
 A change in the altitude of the ROBOT center of gravity.
 Storage achieved by deformation of ROBOT parts. Teams must be very careful when incorporating springs or other items to store energy on their ROBOT by means of part or material deformation. A ROBOT may be rejected at inspection if, in the judgment of the inspector, such items are unsafe.

The following Q&A may also help. http://forums.usfirst.org/showthread...3319#post13319

If you are still unsure, ask the Q&A.