Off robot air compressor

[sanddrag]

at the phoenix regional here w have 1 tank and no compressor on our robot. The inspectors are saying we must fill it with the KOP compressor. They say we may not use our own compressor off the bot to fill the tanks. Ours is actually lower psi and much safer of a setup.

Was this in the rules? What difference does it make which compressor didbthe compressing. Isn't compressed air compressed air no matter what brand compressor it comes from?

[KenWittlief]

yeah, its in the rules that you can only use the suppled KOP compressor for your robot.

part of it is a safety issue. Compressor tanks tend to get water in them, and after a few years they must be discarded even though they look like new on the outside.

I would not want to be in the pits next to a team that dragged in some 30 year old compressor they got at a garage sale. Im sure thats not what your team intends to do, but FIRST has to draw the line somewhere.

So thats where they drew it: KOP compressor only.

[Ricky Q.]

Originally Posted by KenWittlief

yeah, its in the rules that you can only use the suppled KOP compressor for your robot.

part of it is a safety issue. Compressor tanks tend to get water in them, and after a few years they must be discarded even though they look like new on the outside.

I would not want to be in the pits next to a team that dragged in some 30 year old compressor they got at a garage sale. Im sure thats not what your team intends to do, but FIRST has to draw the line somewhere.

So thats where they drew it: KOP compressor only.

Yup.

R96 - Pneumatic Storage
Teams are not allowed to remove or adjust the 125-psi set relief valve attached to the compressor.
You may only use the Thomas Industries compressor and Clippard Instruments air storage tanks provided in
the Kit to compress and store air on the robot. You may not use extraneous lengths of pneumatic tubing to
increase the storage capacity of the air storage system.

[Elgin Clock]

That is one drawback of pneumatics as far as we are concerned.

To use pneumatics, you are required to have on your bot the cylinder, solenoid valve, compressor, tanks, gauge and anything else for your system.

The bad thing is that all that is added into your weight.

If you need one little cylinder on your bot, you are talking 10lbs just for the system to run it.

Sometimes it's not even worth it.

That's why we scrapped pneumatics this year in lieu of motors this year.
We actually saved weight.

[JonBell]

Also of note, when using the off-robot compressor:
You MUST:
Put a 20A breaker right after the power source
Put a spike in between the compressor and the power source

We found the spike part to be quite a pain in the behind. We have it set up now so that we plug it into the last relay port on the robot and that trips the spike.

Otherwise, you are not legal.

[ericand]

You do not need the compressor on your robot. You just need to
use it to fill your tanks. We use a minimal amount of air on our
robot and we drag the KOP compressor along to fill the tanks
between matches.

[KenWittlief]

Originally Posted by Elgin Clock

To use pneumatics, you are required to have on your bot the cylinder, solenoid valve, compressor, tanks, gauge and anything else for your system.

what Eric said - you can make a very small / very light package for pneumatics if you only put one tank on your bot, with one small cylinder, the pressure gauge and one valve.

[Elgin Clock]

Originally Posted by ericand

You do not need the compressor on your robot. You just need to
use it to fill your tanks. We use a minimal amount of air on our
robot and we drag the KOP compressor along to fill the tanks
between matches.

Hmm.. Can you quote where in the manual it says you do not need to have a compressor on your bot? I was under the assumption from what we have done in the past that it had to be on their.

[ntroup]

Originally Posted by Elgin Clock

Hmm.. Can you quote where in the manual it says you do not need to have a compressor on your bot? I was under the assumption from what we have done in the past that it had to be on their.

Rule <R95> from The Robot

<R95> The compressor may be mounted on the robot, or if teams prefer, they may leave it off their robot, and
pre-charge and store compressed air in the storage tanks prior to bringing their robot onto the playing field. If
you elect to use pneumatics on your robot, your pneumatic system must contain as a minimum the following
components, connected in accordance with this section.
• Pressure gauges to display the “working” and “stored” air pressure.
• An accessible pressure vent valve to manually relieve the stored pressure

This seems to say you do not need the compressor, if your prefer, and can charge it prior to a match.

-Nate

[Al Skierkiewicz]

To add to Nate's post...
<R97> The Nason pressure switch must be connected to the output end of one of the Clippard tanks to sense the tank’s pressure. The two wires from the pressure switch must be connected directly to a digital input and ground terminal on the Robot Controller, and the controller must be programmed to sense the state of the switch and operate the spike relay that powers the compressor. The Parker Pressure Vent valve must be connected to a Clippard tank such that, when manually operated, it will vent to the atmosphere to relieve any stored pressure. The valve must be placed on the robot so that it is visible and accessible.

Although First is trying to decide what to do in this case, thus far (as in the past) it will be necessary to connect the pump through a Spike relay as specified above. Most teams to use this method, connected the pump output to the Parker Valve, then close it when up to pressure. In the past, it was then possible to demonstrate that the pnuematic system was able to achieve no greater than 120 PSI at the high side (Clippard Tanks) and that there was some kind of automatic shutoff that could be demonstrated for the inspector or field personnel. At a minimum expect that field judges will check your pressure to be sure it is not higher than 120 PSI, the consequence could be to drain your pnuematics before competing or possible DQ.
As always, anything that looks unsafe in any way, will not be allowed.

[sanddrag]

As a note, the system they are making us use is very dangerous. Nobody has another relief valve we can use so we bleed off the line from compressor to robot. So when we are done filling, we are pulling off a pressurized 120psi line. Very bad. The system we had before was much more safe, with a quick release and everything. We were too safe for the rules.

At least they aren't making us use a Spike.

One odd thing though is that they said we may use whatever tank we want off the robot.

Nothing against inspectors, they are just enforcing the rule. But the rule is putting us in danger, and is highly illogical. My 120psi air is just as good as your 120psi air, is it not?. Air is air. The only difference is in safety while filling, and our old system was superior. Regulated and quick released, and impossible to be over 100 psi.

PS. does anyone have the exact corresponding rule from last year?

[Al Skierkiewicz]

Sandrag,
The rules are nearly identical to last year as quoted above, only the numbers have been changed to protect the innocent. The inspectors have been told that the kit compressor must be used and if off the robot, must use a spike to control it. I agree that unsafe practices must be avoided, no exceptions. What does the safety officer have to say on this one?

[KenWittlief]

Originally Posted by sanddrag

...
One odd thing though is that they said we may use whatever tank we want off the robot....

who said you could use a tank off the robot?

why would you want an external tank to charge your robot?

[Kirk]

I have read update 18 and understand that FIRST wants us to hook up our off-board compressor to a robot controller and use a spike, pressure switch and all that. Is this really going to be enforced? In L.A. we were told that we had to wire an in-line 20 amp breaker in case of short and prove that we had the proper regulators and that we could not pressurize the robot to over 120 psi. We did all that and had no further issues. Do we really have to shell out $600+ dollars for another controller and go through all the hassle of programming and wiring it up or will our in-line breaker be sufficient? I am mainly looking for input from lead inspector or other official personnel at nationals.

[fimmel]

a spike can be controlled w/out the whole robot controller. i would have to look up the exact pinouts but we put our compressor on the cart and used the presure switch and a spike to control it. pm me if you realy need the diagram cause ill dig one up.