2013 running 2 - VI air compressors legal?

[marccenter]

Is it legal to run dual air compressors this year? Would there be any practical plumbing problems to architect around?
Would there be an issue with using the FRC Labview Vi's which are typically design around the use of one compressor and Nason shut-off switch?

[Joe Ross]

See R80.

[CalTran]

While R80 does specify that you can only run one on board compressor, it would be legal to run multiple off board compressors, so long as you include the control and plumbing hardware on the robot. IE 2 spikes, 2 regulators, 2 valves, etc. etc. etc.

[Racer26]

Why would you want to? Its not like off-board you gain anything by having two, since the time between matches is so large.

[JamesCH95]

Originally Posted by 1075guy

Why would you want to? Its not like off-board you gain anything by having two, since the time between matches is so large.

Saver wear on the on-board compressor. And faster recharging for those back-to-back elimination matches.

[Racer26]

I have yet to see an FRC compressor dead from wear in 10 years of competition. Not saying it doesn't happen, just seems infrequent enough that it shouldn't be a concern sufficient to warrant such an overkill solution.

and unless you have an extraordinarily large quantity of storage tanks on board, I've never seen an FRC bot take more than about 45-60 seconds to fill itself.

[JamesCH95]

Originally Posted by 1075guy

I have yet to see an FRC compressor dead from wear in 10 years of competition. Not saying it doesn't happen, just seems infrequent enough that it shouldn't be a concern sufficient to warrant such an overkill solution.

and unless you have an extraordinarily large quantity of storage tanks on board, I've never seen an FRC bot take more than about 45-60 seconds to fill itself.

You and I have clearly had different experiences in FRC

Not that I've seen a dead compressor, but I've definitely noticed compressors getting weaker after a competition.

[FrankJ]

R80 applies to the compressor on board or off board. So either way, you only get one. But only your inspector knows for sure.

[Al Skierkiewicz]

Originally Posted by CalTran

While R80 does specify that you can only run one on board compressor, it would be legal to run multiple off board compressors, so long as you include the control and plumbing hardware on the robot. IE 2 spikes, 2 regulators, 2 valves, etc. etc. etc.

No...
R80
Compressed air on the ROBOT must be provided by one and only one compressor.
This gets everyone every year. You may not, under any circumstances, fill the tanks on the robot with anything other than one and only one FRC legal compressor under cRio control.
The motor on the Thomas compressor is very close to the same internal construction as a CIM motor. We have lost several over the years due to worn bearings, damaged or worn brush assy. or external metallic debris. The surprising thing is we have not lost a piston assy although the seals do dry out with use.

[Jimmy Nichols]

Originally Posted by 1075guy

...and unless you have an extraordinarily large quantity of storage tanks on board, I've never seen an FRC bot take more than about 45-60 seconds to fill itself.

For Logo Motion our robot had 5 Pneuaire storage tanks that took ~5 minutes to fill.

[Racer26]

Originally Posted by Al Skierkiewicz

No...
R80
Compressed air on the ROBOT must be provided by one and only one compressor.
This gets everyone every year. You may not, under any circumstances, fill the tanks on the robot with anything other than one and only one FRC legal compressor under cRio control.
The motor on the Thomas compressor is very close to the same internal construction as a CIM motor. We have lost several over the years due to worn bearings, damaged or worn brush assy. or external metallic debris. The surprising thing is we have not lost a piston assy although the seals do dry out with use.

For the record, I'm still of the opinion this is a crappy rule with unclear intent.

1075 built our power wheelchair-gone-forklift cart to have an onboard compressor, which was powered by the 2004 IFI control system that it ran on, controlled by a pressure switch just like an FRC robot, running the older Thomas compressor, just like an FRC robot, but we were not allowed to charge the system at competition with it, because the robot itself wasn't controlling it.

Its no more or less safe, and the argument of it uses battery power from another source is silly because I can change the battery in my robot after I've charged the air system with the dead one from last match.

[Al Skierkiewicz]

Phil,
You can have your opinion but the rule is the rule. The rule is not presented as a safety issue, it is just a rule. Pneumatics will be inspected according to the pneumatics section. To remind everyone, you need to pass inspection in order to gain points and avoid other penalties. For instance read G5.

[Racer26]

Not sure why you think my name is Phil (it's not).

I don't challenge that it IS a rule, nor that inspectors shouldn't enforce it. Of course you need to pass inspection (presumably by complying with the rules) in order to compete. I think you're taking the argument a bit far.

I do think that inspectors *could* have a hard time enforcing it though. For example, some of the robots that we had on that cart HAD their own on-board compressors, it was simply convenient to use the cart-mounted one.

We've been told not to use it to pressurize the robot before and complied, and the volunteers at the event(s) it was mentioned at seemed to indicate that it was somehow a safety concern because the robot wasn't controlling it, and that was the logic behind the rule.

I further believe though, that questioning the reasoning behind a rule is VALID, and IMPORTANT, because often, even though a rule may have made sense for one reason or another in the past, doesn't mean it still makes sense now. Intent is important. This is a rule that has been around for years, for what appears to be no reason at all.

To be sure, this is the specific portion of the rule I don't understand the reasoning behind.

Originally Posted by FRC Game Manual

R80
<snip>... Off-board compressors must be controlled and powered by the ROBOT.

The only reasoning I can come up with, is that they want you to be under software control so the pressure switch will shut things off appropriately. There are lots of ways to solve that without requiring the robot to be the one controlling it.

A better rule might read:

"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. Off-board compressors must still be controlled by a pressure switch to ensure a maximum pressure of 120psi."

I apologize if my preference for a rulebook which promotes maximum freedom of configuration to the teams, while still achieving its goals doesn't sit well with you. The way the bumper and other pneumatics rules keep getting simplified and loosened, and the way HQ has expressed a desire to simplify the rulebook seems to agree with me. "That's the way we've always done it." just isn't a good reason to continue doing something a particular way.

[Al Skierkiewicz]

Sorry,
I thought Phil was your name. Sorry. There is no mystery to the reason behind this rule. It is in the first paragraph of Section 4...

In addition, another intent of these rules is to have all energy sources and active actuation systems on the ROBOT (e.g. batteries, compressors, motors, servos, cylinders, and their controllers) drawn from a well-defined set of options. This is to ensure that all Teams have access to the same actuation resources, and to ensure that the Inspectors are able to accurately assess the legality of a given part.

Emphasis mine. Think about this rule as being as hard and fast as the robot battery, the PD, the legal motor list and cRio. The penalties show how serious the GDC is about enforcement. For instance...

G05
When placed on the FIELD, each ROBOT must be:
A. in compliance with all ROBOT rules (i.e. have passed Inspection),
If it is not a quick remedy: the ROBOT will be DISABLED and must be re-Inspected.

G03
ROBOTS whose operation or design is unsafe are not permitted.
Violation: FOUL & DISABLED. If the issue is due to design: Re-Inspection.

T06
A TEAM is only allowed to participate in a MATCH and receive Qualification Points if their ROBOT has passed
Inspection. If it is discovered after the start of the MATCH that a ROBOT did not pass Inspection, the entire ALLIANCE will receive a RED CARD for that MATCH.

T08
At the time of Inspection, the ROBOT must be presented with all MECHANISMS (including all COMPONENTS of each MECHANISM), configurations...

To use a second compressor of any type means that the robot has not passed inspection. I think that covers it...

[Racer26]

We clearly don't see this as an issue of the same, or even similar magnitude. You continue to argue about how it constitutes a violation worthy of claiming a ROBOT wasn't inspected simply because its air system was pressurized by some other source, regardless of whether that source is substantially the same as the presently prescribed system or not.

You just made the argument I've heard so many times, that it needs to be supplied by the ROBOT's battery, because everyone has those, and they have a limited supply of power, so that makes it the same for everyone.

The source of the 12VDC power that powers the compressor is irrelevant in any substantial way, since I can change my battery AFTER I've pressurized the system and before the MATCH. Whether I use a robot battery, a deep cycle marine battery, or a solar fusion reactor to power it changes nothing about the ROBOT as it sits in the ARENA at the start of a MATCH, with a fresh battery and a pressurized air system.

As for the rules you cited:

G03 doesn't apply, its not an unsafe design or operation.

G05 may apply, but it IS a quick remedy, opening the air valve remedies any perceived problem that charging from an external source created, so no DISABLED ROBOT or Re-inspection necessary.

And I suggest that T06 or T08 aren't even relevant to the discussion, as I never suggested more than one compressor.

For sake of argument, though, I don't believe that the intent of the "one and only one compressor" rule is to prevent me from having equally functional, and equally legal on their own off-board compressor panels (controlled and powered by the ROBOT, in accordance with R80), but rather, its intent is to say that you are only to have one compressor provide the air at any one time. Whether this time I use compressor A and next time I use compressor B doesn't particularly matter, otherwise, what happens when one breaks during a competition?