How much air can be stored onboard?

[Silver]

My team feels like we're going to have so many pistons sucking up so much air that we'll run out. I was asked to scan the manual for a max storage limit on the robot, but I found none. Anyone know how much air we can store in tanks onboard our robot?
Also, if we have a compressor onboard, can we still precharge the storage tank(s) before autonomous?

Thanks again,
Digby Baker-Porazinski
Team 5236 - Man o' War

[z_beeblebrox]

There's no limit in the rules, though you're obviously limited by space, weight and cost.

The tanks are normally filled before autonomous, whether or not a team has a compressor..

[Adamz_]

Hey there! Ill do my best to answer what i can. I know that you are allowed to pre-charge your air tanks when your are queing for a game. As for how much air you can store, i don not think there is a limit to how many tanks you can have, you just have to make sure that all the pressure in the tanks is 125 psi max, and the psi everywhere else is 60.

Good luck this year!

[one4robots]

Hey there! Ill do my best to answer what i can. I know that you are allowed to pre-charge your air tanks when your are queing for a game. As for how much air you can store, i don not think there is a limit to how many tanks you can have, you just have to make sure that all the pressure in the tanks is 125 psi max, and the psi everywhere else is 60.

Good luck this year!

One small correction...max storage is 120 psi. All pneumatics components must be rated for 125 psi or better.

[MrBasse]

One small correction...max storage is 120 psi. All pneumatics components must be rated for 125 psi or better.

One more small addition, while this is right it probably is near impossible...

According to R80: Off-board compressors are permitted, however the compressor must be controlled and powered by the ROBOT.

This means that, due to the required pressure switch, this pressure will more likely be somewhere between 108 and 118 psi. The only way our switch has ever allowed 120 psi is when an inspector shorts it to test the relief valve. The one we used last year was our best of the three we have, and it only would reach 109 psi. The worst one shut off around 92 psi.

[Phyrxes]

Maximum working pressure is defined as 60 PSI, but you may choose to use less or get fancy with multiple branches at different working pressures. The lower bound of working pressure is defined by the solenoids used.

[EricH]

For a 28" x 28" x 60" robot, you can theoretically store 47,040 in^3 of air onboard.

The problem, of course, lies in all the structure and electronics required to actually HOLD the air, some of which are required, which displace some air as well as removing some air storage capacity. Actually pressurizing the air will need some thicker material, thus even less storage capacity.


Oh? The air actually has to DO something? That complicates things. See previous paragraph.

(If you can't tell, this post is not intended to be serious. Sometimes, the GDC will get a question similar to the first one on some other component, and answer with something like the above.)

[Wayne Doenges]

At Crossroads we (the inspectors) would watch for teams with carts that had compressor other then the legal KOP compressor. If they used them in que to charge their robot, they would be in violation of the off robot compressor rule. You have to use the KOP compressor to fill your robot. Period.

[cgmv123]

At Crossroads we (the inspectors) would watch for teams with carts that had compressor other then the legal KOP compressor. If they used them in que to charge their robot, they would be in violation of the off robot compressor rule. You have to use the KOP compressor to fill your robot. Period.

Note that you are allowed to use one battery to charge the compressor and replace it with a fresh battery before going on the field. (Q88 (https://frc-qa.usfirst.org/Question/88/is-it-permitted-to-use-one-robot-battery-to-charge-your-pneumatic-systems-just-prior-to-a-match-and-then-replace-that-partially-spent-battery-with-a-freshly-charged-battery-right-before-going-on-the))

[FrankJ]

As a practical matter you are limited by the rate you can charge your reservoir with your legal compressor. In elimination matches, the cycle times get shorter along the opportunity to recharge your system between matches. Consider having to start a match with a discharged system. With more storage volume, it takes longer to bring up your system to a usable pressure. Sometime less is more here.

[PVCMike]

Keep in mind that the more capacity you have, the longer it will take to re-charge when depleted. Sometimes it's better to have less storage that reaches full pressure faster.

[Qbot2640]

At Crossroads we (the inspectors) would watch for teams with carts that had compressor other then the legal KOP compressor. If they used them in que to charge their robot, they would be in violation of the off robot compressor rule. You have to use the KOP compressor to fill your robot. Period.

R79 - Compressed air on the ROBOT must be provided by one and only one compressor. Compressor specifications may not exceed nominal 12VDC, 1.05 cfm flow rate.

You are not required to use a specific "KOP" compressor - but the one you use must comply to R79.

As far as the "offboard" allowance - this really does not change the pneumatic circuit - just puts the compressor in the pit, or on the cart. Space and weight savings at the expense of not recharging during the match.

[sircedric4]

In theory infinite. In practice the maximum will be around 2 gallons given the highest compressing legal compressor. Our robot last year was all air to climb the pyramid. We did numerous tests and if you want to charge in 5 minutes, 2 gallon worth of air is the max. During eliminations you will only have 5 minutes between matches as you win unless you burn your one time out.

[Tem1514 Mentor]

Some thing else to consider is; where is your compressor?

When it is on the robot during a match you may store 120 psi but when the compressor is NOT attached to the robot you may only store 60 psi.

[amesmich]

I don't think thats entirely true. This is only if your regulator is off the bot as well. See R86