Precharging

[Chris is me]

Originally Posted by Al Skierkiewicz

Safety is our first priority. If the venue requires really tight quarters in the queue, then they may ask (The LRI is the messenger) teams to remove any air in the expectation that injuries will be minimized. If your robot moves when pressurized, I would ask you to wait to pump up. If you consistently demonstrate an unsafe condition, the LRI, FTA and UL Safety people will visit you with suggestions up to and including disabling the offending parts until you can correct the condition. (See R9)

This confuses me. So teams with offboard compressors can't use pneumatics at some venues? If there is a rule at these venues to dump all air in queueing, there is no opportunity to fill the tanks and change the battery between queueing and being on the field for the match. Not to mention how this hurts teams that take more than 2 minutes to fill their air tanks. If this is a constraint teams should expect to ever have to deal with, it should be in the rules so that teams don't design robots that are disadvantaged in these scenarios.

I know you're just the messenger, talking about rules at specific events, but this just seems like a really big deal at first glance. I think I'm misunderstanding the situation here.

[dradel]

You would have to bring the off board compressor with you to que. not a huge deal seeing as it must be powered by the robot per rules anyway.

[JesseK]

Originally Posted by dradel

You would have to bring the off board compressor with you to que. not a huge deal seeing as it must be powered by the robot per rules anyway.

Depends on the cart, TBH.

[FrankJ]

When charging your pneumatic system, expect things to move. especially when using air pressure to hold starting configuration. Most solenoid valves used in FRC will pressurize one side of the cylinder when disabled. The only way to charge the pneumatics is to enable the robot. Depending on the robot not to move when enalbed is an unsafe mindset.

[Chris is me]

Originally Posted by dradel

You would have to bring the off board compressor with you to que. not a huge deal seeing as it must be powered by the robot per rules anyway.

Yeah, no, it's a huge deal.

You can't tether to the robot on the field, so you would have to precharge while queueing - but if you're not allowed to charge while queueing either, and you're required to dump air in the queue line, it's impossible to start the match with air.

It is legal and sometimes a very good idea to build a robot with no on-board compressor, but with many air tanks. These tanks can take upwards of 2 minutes to fill. These robots basically need to be filled in the pit or partially in queueing in order to be able to compete. If these designs are feasible at some competitions but not at others, that really isn't fair.

[dradel]

I missed the part about not being able to tether in que.

[Al Skierkiewicz]

Originally Posted by Ari423

Is is very possible to charge a pneumatic system with little to no danger.

Ari,
You know this and I know this, but many teams do not. I have been hit by moving robot parts many times, including a few this year. I have seen big robot parts move when someone bumped the controls thinking that nothing was enabled. I have seen students operate a valve manually to test something and picked the wrong valve to operate. Just this year I have seen teams attempt to connect pneumatics to a speed controller, I have seen a coke bottle used as a storage tank, I have seen teams use various pumps to pressurize their systems and I have seen really big pistons used for climbing and shooting.

Everyone,
This is not a FIRST rule. It may be a restriction from the venue, the insurer or virtually anyone involved with the event, not employed by FIRST. And it may change from event to event. Remember, at every event we are guests. We are guests that want to be invited back in the future. Now here is some food for thought...Would you want a judge see your robot hurt someone? If you were hoping for Chairman's, Gracious Professionalism or even Safety, would that knock you out of the top spot? What if the person that was hurt was a judge?

[ctt956]

Originally Posted by dradel

You would have to bring the off board compressor with you to que. not a huge deal seeing as it must be powered by the robot per rules anyway.

I think if it's offboard, it doesn't have to be powered by the robot because it's not part of it. I've seen off board compressors not powered by the robot.

[ATannahill]

Originally Posted by ctt956

I think if it's offboard, it doesn't have to be powered by the robot because it's not part of it. I've seen off board compressors not powered by the robot.

Please review R80 including the blue box.

[Al Skierkiewicz]

Summarizing some of the pneumatics rules...
All air used on your robot (except tires) must come from one legal compressor (on board or off board) under control of the Roborio (using a legal pressure switch to sense air pressure) and powered from the same robot battery that is powering the RoboRio.

[ctt956]

Originally Posted by rtfgnow

Please review R80 including the blue box.

I just reviewed it. R80 is below.

The compressor (permitted per R79) may be located off-board, however the compressor must still be controlled and powered by the ROBOT.

And the blue box:

The compressor may be mounted on the ROBOT, or it may be left off the ROBOT and used to pre-charge compressed air in storage tanks on the ROBOT provided the additional restrictions of R85 are met.
The intent of this rule is to permit teams to take advantage of the weight savings associated with keeping the compressor off-board. However, using the compressor off-board of the ROBOT does NOT permit non-compliance with any other applicable rules.

I guess if you have an off board compressor, it needs to be connected to where an onboard compressor would be, which still requires you to enable the robot to charge the air.

[IndySam]

Originally Posted by Al Skierkiewicz

Ari,
I have seen teams use various pumps to pressurize their systems and I have seen really big pistons used for climbing and shooting.

Really AL?, sigh.....


BTW Really big cylinders are usually safer than small one because they move so slowley.

[Al Skierkiewicz]

A team this weekend had two 3/4" bore and maybe 36" stroke to raise a climber.

[Ari423]

Originally Posted by Al Skierkiewicz

A team this weekend had two 3/4" bore and maybe 36" stroke to raise a climber.

Last year we used (2) 1" diam. 24" stroke cylinders to lift the totes IIRC. We ended up with 10 black clippard tanks (we would have out more but we ran out of weight), which lasted us almost the whole match at ~30 psi up, ~15 psi down (with the compressor running). It then took over 5 minutes in the pits or in queue to recharge. If we weren't allowed to precharge before we got on the field (or even if we only got one match in queue to precharge) we would have essentially had a brick with wheels for a robot.